# Pila Charger Voltage Questions?



## recDNA (May 16, 2010)

My PILA consistantly charges to only 4.16 - 4.17 volts. Hitting reset has no effect. It only charges for 10 seconds then goes back to green. (Now I know this is within spec)


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## jmcf1949 (May 16, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

My Pila IBC charges very consistently to the same 4.16/4.17V. I believe this is perfect as it will give me a few more charge/discharge cycles thereby extending the battery life a bit.

Jim - Semper Fi


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## kramer5150 (May 16, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

safety factor perhaps?
My WF-149 only charges to ~4.18, my cells are consistently 4.15 hot off. I personally see this as an advantage. Especially since a good percentage of my lights use buck drivers anyways.


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## jasonck08 (May 16, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I've read of some people's PILA chargers only charging to 4.12v, and some peoples over charging to 4.24v.

I wouldn't recommend the PILA charger despite it being so well "praised" around the CPF community.

Get a hobby charger that you can calibrate the final charge voltage. I can make mine stop at anywhere between 4.18 and 4.22v, and it cost me the same is the PILA charger. It has a digital readout and can charge like 5-6 different battery chemistries.


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## ampdude (May 16, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Don't leave us in suspense.  What model do you use? Does it charge NiZn batteries?


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## recDNA (May 16, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Well I notice the runtime dif so I'd like my PILA to charge to 4.2 as advertised. At first I felt as you do but then I noticed that I'm getting less runtime. I'm disappointed.


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## Ziemas (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> Well I notice the runtime dif so I'd like my PILA to charge to 4.2 as advertised. At first I felt as you do but then I noticed that I'm getting less runtime. I'm disappointed.


Are you sure your DMM isn't off? I was getting funky readings with a bad DMM and my Pila. With a better DMM all is as it should be.


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## hazna (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

My pila seems to charge to 4.20V on one channel and 4.22V on the other channel. One would expect some variation between individual samples. Cheap DMM's are not always that accurate anyway...


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## 45/70 (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> Well I notice the runtime dif so I'd like my PILA to charge to 4.2 as advertised. At first I felt as you do but then I noticed that I'm getting less runtime. I'm disappointed.



That seems odd. The difference between 4.17 Volts and 4.20 Volts with a LiCo Li-Ion cell, is the difference between 97% and 100% charge. I'd say if you actually notice a difference in runtime, that your problem is likely something else.

As for any charger that only charges to 4.17 Volts as opposed to 4.20 volts, I'd look at the bright side, your cells will last longer being charged to this lower level. And, as I said, the difference in capacity should be negligable.

Dave


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## recDNA (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



45/70 said:


> That seems odd. The difference between 4.17 Volts and 4.20 Volts with a LiCo Li-Ion cell, is the difference between 97% and 100% charge. I'd say if you actually notice a difference in runtime, that your problem is likely something else.
> 
> As for any charger that only charges to 4.17 Volts as opposed to 4.20 volts, I'd look at the bright side, your cells will last longer being charged to this lower level. And, as I said, the difference in capacity should be negligable.
> 
> Dave


 
After all the raves about Pila here and paying more than twice what the WF-139 cost I am disappointed. Owner after owner find the same flaw - charging less than the optimum 4.2 volts so it isn't my multimeter. Although the charging algorithm isn't optimal somehow my WF-139 always charges to 4.20 volts. You would think Pila could calibrate them properly or include some sort of manual calibration capability.


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## Ragiska (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> After all the raves about Pila here and paying more than twice what the WF-139 cost I am disappointed. Owner after owner find the same flaw - charging less than the optimum 4.2 volts so it isn't my multimeter. Although the charging algorithm isn't optimal somehow my WF-139 always charges to 4.20 volts. You would think Pila could calibrate them properly or include some sort of manual calibration capability.


for many, 4.2v is non-optimal. i imagine you could easily find someone who would gladly trade you your charger that undercharges cells by roughly 3% so they can get over twice the cell life.


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## Lite_me (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I usually leave the battery questions to the experts here, but I thought I'd add my 2¢. 

I have and use a Pila IBC charger.

As Li-Ion batteries age, they will no longer reach and sustain the optimal 4.2v reading. 

Different manufacturers sometimes result in a different outcome reading. 

Different battery types, ie: 18650s, 16340, 14500s will charge to different states, because of their size, I guess. :thinking: A least this has been my experience anyway. With new AWs of those 3 sizes, The rcr123s top off @ 4.16-4.17, the 14500s @ 4.17-4.18 and the 18650s @ 4.19-4.20. Consistently. 

With all the variables considered above, add contact resistance, DMMs, temperature, resting time, and there's probably others, I think 4.17v is ideal. 

I'm tickled when I see that number. That's what I _want_ to see. That also means that if my readings happen to be on the low side, I have that bit of cushion. Perfect!


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## TooManyGizmos (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I agree with recDNA ... and I like that manual calibration capability... Idea.




recDNA said:


> After all the raves about Pila here and paying more than twice what the WF-139 cost I am disappointed. Owner after owner find the same flaw - charging less than the optimum 4.2 volts so it isn't my multimeter. Although the charging algorithm isn't optimal somehow my WF-139 always charges to 4.20 volts. *You would think Pila could calibrate them properly or include some sort of manual calibration capability.*


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## recDNA (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Ragiska said:


> for many, 4.2v is non-optimal. i imagine you could easily find someone who would gladly trade you your charger that undercharges cells by roughly 3% so they can get over twice the cell life.


 
"With all the variables considered above, add contact resistance, DMMs, temperature, resting time, and there's probably others, I think 4.17v is ideal. "


And if Pila advertised that it charged to 4.17 volts because that is optimal the purchaser can make an informed choice. 

If your Olight SR90 achieves lower than advertised output are you happy because now you have increased runtime? You might be satisfied but I buy a light like that for maximum output and I buy a more expensive charger to more accurately and safely charge to EXACTLY 4.20 volts.

I don't care if 99/100 readers here prefer 4.17 volts. If a product is supposed to charge to 4.2 volts it should charge to 4.2 volts period. No excuses. The failure to do that makes it a less than superior product. Reviews that bubble with praise for its safe algorithm should also warn that it fails to charge to 4.2 volts. In fairness, I have read such posts but I think it is fair to say this product does not do as it is advertised to do.

Perhaps one reason I have different priorities is because I recharge fairly seldom. I'm more of a collector than constant user. I seldom use any of my flashlights for more than 10 minutes at a time. I really don't care at all about extending battery life. I do care about safety though. If the algorithm is safe as advertised it should be able to safely charge to 4.2 volts. Those who prefer to charge to less than 4.2 volts can always take their batteries out before the light turns green. I have no option to fully charge my batteries on this charger.

None of my batteries has been charged more than 3 times and all of my batteries of all sizes and chemistries charge to 4.16-4.17 volts on the Pila. These same batteries charge to 4.2 volts on the WF-139. There may be no practical reason I NEED a perfect 4.2 volt charge but I paid for it and so I expect it. I could easily be mistaken about less runtime. I never measured it scientifically. My disappointment about the failure to charge to 4.2 volts probably colored my judgement. I do feel safer. I hope THAT belief is justified and I suspect it is.

I will continue to use the Pila with my IMR batteries because they lack protection and my RCR-123 batteries because I think they may be more susceptible to damage from the WF-139 algorithm. I'm not saying it is a bad product. I am saying it is a less than great product because it fails to do as advertised. I'll charge my protected 18650's on my WF-139. BTW, all of my lithium rechargeable batteries are AW.


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## jasonck08 (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



ampdude said:


> Don't leave us in suspense.  What model do you use? Does it charge NiZn batteries?


 
I just use a Turnigy Accucell-6. They are like $24+shipping @ HobbyKing.

With the voltage calibration you can adjust the final charging voltage. When i got mine it would only charge to 4.17 or 4.18v. Then I calibrated it a bit and can usually get it to termiante the charge at 4.20 right on the dot.


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## Bullzeyebill (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

The charger should charge to 4.2 volts, or whatever an individual LiIon cell *will allow.* 

Bill


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## 45/70 (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> After all the raves about Pila here and paying more than twice what the WF-139 cost I am disappointed. Owner after owner find the same flaw - charging less than the optimum 4.2 volts so it isn't my multimeter. Although the charging algorithm isn't optimal somehow my WF-139 always charges to 4.20 volts. You would think Pila could calibrate them properly or include some sort of manual calibration capability.




OK, I think I understand your disappointment. Let me cover a few points that will perhaps allow you to feel better about your Pila.

First, I wouldn't say that charging to less than 4.20 Volts is necessarily a flaw. The Magic "4.20 Volts" isn't really magical at all. It is merely the center of the 4.20 +/- 0.05 Volt charging specification. Charging to less than 4.20 Volts allows more cycle life of cells at the cost of reducing the charge by a few percent. Charging above 4.20 Volts reduces cycle life, but allows a few more percent capacity to be obtained. 4.20 Volts is just the middle ground here.

Second, as Lite_me mentioned, a charger that uses a proper algorithm, but with a fixed charge rate cut off, such as the Pila utilizes, will not charge cells of different capacities, all to the same voltage. The higher the capacity of the cell, the higher the end voltage will be. The lower the capacity of the cell, the lower the ending voltage will be. This is a result of having a fixed charge rate cutoff point, as opposed to a variable one, such as a hobby charger utilizes.

A third point, a charger that forces the cell to a certain voltage before terminating the charge, rather than utilizing the 0.1-0.03C CV cutoff of a proper algorithm, such as the WF-139, abuses the cell and shortens the cycle life. As I jokingly referred to in another thread, this could be seen as an advantage, as it speeds up the death of cells that are in suboptimal condition, and forces you to buy new ones sooner.  Note also, that while the Pila's fixed cutoff is a departure from the proper algorithm, it usually falls within the 0.1-0.03C range, for most cells that it is used to charge.

One final note, when using a charger which utilizes a proper algorithm, as cells age, the end voltage will gradually become lower, as the IR of degraded cells won't allow the cell voltage to reach the same level as when the cell was in better condition. I look at this as being a handy feature, as it is an additional way you can guage the condition of your cells. This is something that when using a charger such as the WF-139, you will not be aware of, as it will allways charge the cell to the same voltage.

I hope these comments allow you to look at your Pila in a different light. As I have said before, I don't own a Pila and never have, but the information available here on the Forums is sufficient enough, for me anyway, to recommend it over most other consumer type chargers out there. Hopefully this will change, competition is a good thing for everybody, but really I think you made a good choice. 

Dave


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## recDNA (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Thanks Dave...although I don't understand all the technical reasons for your argument I DO get the point. 

A far as battery degredation all of my batteries are AW and none have been charged more than 3 times.

My point is more simple but I think still fair. If the product design makes it unable to charge to 4.20 volts or the developers believe 4.20 isn't optimal it should simply be advertised that way. 

Advertise "The superior charging algorithm of the Pila Charger is designed to cut off from 4.16 to 4.18 volts depending upon the size and condition of your batteries because that will increase the number of charging cycles " (followed by an explanation like yours). 

Then the purchaser can decide and even the novice won't be disappointed with the performance of the charger.

Isn't that fair?

Again, my intent isn't to rip the product. If it is safer it is better as far as I'm concerned. I just like the opportunity to make an informed purchase.


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## 45/70 (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Yeah, I could go along with you on that, rec. The problem that all of these chargers share in common though, is that they are really good at telling you how wonderful they are, but always fall short of telling you any actual useful information about them. It seems that resposibility falls on us, the users, to determine. 

Dave


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## Ragiska (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> A far as battery degredation all of my batteries are AW and none have been charged more than 3 times.



li-ion cells degrade with both cycles _and_ TIME. they begin degrading from the second they are made, and the loss is non-recoverable. storing at full charge increases the rate of degradation.


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## recDNA (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I bought the oldest ones in February. The newest in May. They all charge to 4.16 - 4.17 volts. As I understand it the charger is designed to do this. 

I really don't wish to continuing arguing about this. I think this ground has been covered and I don't want to annoy the moderators.

I will ask one last question. Do you think Pila should advertise that it designs their chargers to charge to 4.16 - 4.19 volts to avoid confusion?"


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## recDNA (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



45/70 said:


> Yeah, I could go along with you on that, rec. The problem that all of these chargers share in common though, is that they are really good at telling you how wonderful they are, but always fall short of telling you any actual useful information about them. It seems that resposibility falls on us, the users, to determine.
> 
> Dave


 

Thanks again for your help.


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## Ragiska (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> They all charge to 4.16 - 4.17 volts. *As I understand it the charger is designed to do this. *



i suggest you re-read the posts then. it depends greatly on the cells themselves, and tolerances (which are within acceptable limits).

the pila is designed to safely charge the cells to a *proper level*. it is simply your preconception that that means it MUST be 4.20000v exactly.


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## olephart (May 17, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I don't know what you are measuring the voltage with, but how do you know you are getting accuracy to .01V, or less?

A Fluke 175 is good for +/- .01V in that range, so a 4.170V reading could be 4.160 to 4.180. Most any meter selling for under $100 has specs around 2-3%. Some are pretty close despite the specs, but you would have to test em on an individual basis to find out.

I have a $29 meter that reads .015 less than the Fluke in the 3.0 to 3.5V range. If ya had a battery that was exactly 3.2V, the Fluke could measure it at 3.190 and be in spec. The $29 unit would read 3.175 and be in spec.

I have read that an occasional Harbor Freight meter is more accurate than a Fluke in certain ranges. Anyway, claiming a fault due to .03V requires some credentials for the meter before it is a concern.


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## Ziemas (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> Thanks Dave...although I don't understand all the technical reasons for your argument I DO get the point.
> 
> A far as battery degredation all of my batteries are AW and none have been charged more than 3 times.
> 
> ...


I think you are over thinking this quite a bit. If you wish for your cells to be charged to an *exact* voltage then buy a hobby charger which you can program yourself. 

What is your purpose in whining about this here? Have you contacted Pila about it yet if it so concerns you? Also, as specifications seem to be very important to you, the Pila charger is only spec'ed to be used with Pila batteries. Are you you using Pila or some other sort of cell? If you aren't using Pila cells then you don't really have anything to complain about. 

BTW, several have asked about what DMM you are using. Could you please tell us?


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## recDNA (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I just wonder how objective some here are.

1. Your meter is no good.

2. Your batteries are no good. (Many users get the same readings I do and even argue it is "ideal". My rechargeables charge to 4.2v on wf-139 with my meter. My meter measures the voltage of primary cells to correct values)

3. 4.17 volts IS ideal so meter and battery ARE good.

4. I should have bought a hobby charger if I want batteries charged to 4.2 volts.


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## recDNA (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

"Just when I thought I was out... they pull me back in"

1. Your meter is no good. (Many users get the same readings I do and even argue it is "ideal". My rechargables charge to 4.2v on wf-139 with my meter. My meter measures the voltage of primary cells to correct values. If my meter were off would that discount all the other arguments about Pila SHOULD charge to 4.17 volts?)

2. Your batteries are no good. (Some were charged on their very first cycle on the Pila. All are AW)

3. 4.17 volts IS ideal so meter and battery ARE good. (Actually the dealer I purchased from says +- .03 v is normal for this charger and within spec. That being the case it was my suggestion that Pila advertise same.)

4. I should have bought a hobby charger if I want batteries charged to 4.2 volts. (I thought the Pila would do the job and it's not horrible - just has IMHO a flaw)

5. I should contact the manufacturer and not "whine" here. (I've repeatedly said I will keep my Pila and continue to use it for some batteries because it may be safer so I don't think I'm whining nor unduly ripping the product. I don't even regret the purchase. I just wish the Pila would charge to 4.2 volts. Just my preference. Heck, when I first posted this I expected 20 posters to say "Mine always charges to 4.2 volts - you should seek an exchange." If ALL posters did that none of us would have any hint which products were best. We'd hear nothing but praise for every product.)

By the way.. have you noted that some of these arguments are mutually exclusive?

Anyway, I've answered all of the above except the last in previous posts. #5 is just insulting. I'm not "whining". This a a forum for the free exchange of ideas. If one is free to extol the virtues of a product one should feel free to point out a perceived weakness (even if others dispute it IS a weakness). Now please - this topic has been beaten to death. I prefer a charger that uses a safe algorithm AND charges to 4.2 volts. I shouldn't expect this according to some. A few even agree with me. I get it.


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## Ziemas (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> I just wonder how objective some here are.
> 
> 1. Your meter is no good.
> 
> ...


Why do you think people are being biased just because they don't agree with you? Did you post looking for sympathy or to explore what is going on with your charger? 

How do you know your meter is correct? What kind are you using? 

FWIW, I tested my meter (a Velleman DVM850BL) at the shop against several Fluke meters and they all measured the exact same. That's good enough for me. It also measures my Pila charging to 4.20V. My old rubbish meter was telling me the Pila was charging to 4.24V.


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## Bullzeyebill (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

You have asked a question, and people have responded. Your OP did not suggest that you would not be appreciative of those responses. You have made your point, and you are standing by it in the face of good information given you, and now your are wondering if people are being objective with you. I see no further purpose to this thread.

Bill


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## Ziemas (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> Anyway, I've answered all of the above except the last in previous posts. #5 is just insulting. I'm not "whining". This a a forum for the free exchange of ideas. If one is free to extol the virtues of a product one should feel free to point out a perceived weakness (even if others dispute it IS a weakness). Now please - this topic has been beaten to death. I prefer a charger that uses a safe algorithm AND charges to 4.2 volts. I shouldn't expect this according to some. A few even agree with me. I get it.


Why wouldn't you contact Pila about it? They are the folks who can actually help you. Or is it that you'd rather shout about your unique problem on the internet out of some sort of spite or anger at Pila without actually looking for a solution or giving Pila a fair chance to fix your 'problem'? 

I know that my Pila charger charges to 4.20v, as do the vast majority of other members chargers. It doesn't sound like a weakness with the charger at all..... 

Clearly you aren't interested in what people here have to say unless they agree with you. For some reason you've managed to take offense at people trying to offer solutions simply because it wasn't what you wanted to hear.


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## recDNA (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Ziemas said:


> Why wouldn't you contact Pila about it? They are the folks who can actually help you. Or is it that you'd rather shout about your unique problem on the internet out of some sort of spite or anger at Pila without actually looking for a solution or giving Pila a fair chance to fix your 'problem'?
> 
> I know that my Pila charger charges to 4.20v, as do the vast majority of other members chargers. It doesn't sound like a weakness with the charger at all.....
> 
> Clearly you aren't interested in what people here have to say unless they agree with you. For some reason you've managed to take offense at people trying to offer solutions simply because it wasn't what you wanted to hear.


 
Re-read my posts before criticizing them. As I said I DID contact the dealer and was told ,"_A discrepancy of .03V is typically within the tolerance of this type of product_.".

I take offense at the word "whining" as I suspect would you.

If the consensus here were "Your charger SHOULD charge to 4.2 volts. Return it" I would have. I think if you read all the posts here many folks say the charger should only charge to 4.17 volts, that it is not only normal it is preferable.

Perhaps I should have started a poll.


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## Ziemas (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> Re-read my posts before criticizing them. As I said I DID contact the dealer and was told ,"_A discrepancy of .03V is typically within the tolerance of this type of product_.".
> 
> I take offense at the word "whining" as I suspect would you.
> 
> ...


Did you actually contact Pila? You know, the people who make the charger? Their US branch is very helpful and has great customer service. The dealer isn't Pila, unless you bought directly from them. 

Exactly what DMM are you using? Is there any reason you continually refuse to tell us? It's germane to the topic at hand.


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## Meterman (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

The charger IC has a voltage regulation of min. 4.168V, normal 4.200V and max. 4.232V.

Perhaps they want to be sure not to exceed 4.200V to avoid any regress problems and thus lower the voltage range by using additional external components to be 4.200V the max. value. :thinking:

Wulf


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## Mr Happy (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Ziemas said:


> Did you actually contact Pila?


One thing that perhaps has not been touched on more than briefly here is that the Pila IBC is only supported when charging Pila brand cells like the 600S. If you are charging some other cell like AW then Pila will likely not get involved.

Do Pila claim that their product charges their cells to exactly 4.20 V? I have not scrutinized their literature, but I imagine they say simply that it charges their own brand of cells properly and safely. They have no need to say more.


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## recDNA (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Mr Happy said:


> One thing that perhaps has not been touched on more than briefly here is that the Pila IBC is only supported when charging Pila brand cells like the 600S. If you are charging some other cell like AW then Pila will likely not get involved.
> 
> Do Pila claim that their product charges their cells to exactly 4.20 V? I have not scrutinized their literature, but I imagine they say simply that it charges their own brand of cells properly and safely. They have no need to say more.


 

Bottom line is unless virtually every poster reported their Pila charged to exactly 4.2 volts it isn't worth my while to return it just for the difference between 4.16 or 4.17 instead of 4.2 volts. I've learned it is not uncommon for them to charge new batteries to 4.17 volts and ±.03 volts may well be in their range of performance. Expecting perfection was probably unreasonable on my part. Whether or not 4.2 volts IS perfection in brand new cells is another matter entirely. It's just what I expected. 

Since Pila were so highly thought of here I assumed they would dependably charge to 4.2 v every time as does my WF-139 (except IMR123 that charge to 4.21 - 4.22v on the WF-139. The _IMR18650 charge to 4.2 as do RCR123 and AW protected 18650_).

Based on all of the knowledgeable posters' explanations I trust that the Pila will be safer for my small cells. I'll charge my protected AW 18650 cells on the WF-139. I'll charge all of my IMR (since they are unprotected) and RCR123 (because they are so small) on the Pila for safety sake.

Not only is the Pila charger made for their own batteries I don't think it is even designed for RCR123 sized batteries so I see no reason to bother Pila about it. If I were the ONLY person getting these results that would be different.

Thanks again to everyone who contributed their opinions and expertise to this thread.


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## TriChrome (May 18, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I think you're lucky to even be getting a constant 4.17 volts on this charger. I personally think it's either a POS, or something else I'm not aware of is up. I also bought into the "Pila IBC charger is the best on the market bar-none" mantra, and I'm now second guessing what all the hype is about. 

Here's my readings on 16 freshly charged batteries. I'm completely new to reading voltages but I've read about 10 threads on here about how to do it, and bought a $50 Sperry autoranging multimeter to measure the voltage (measured right off the charger, positive probe in V omega terminal, negative in COM; unit switched to V (voltage) with a line and 3 dots above it).

All batteries except the protected 16340's are brand new, and were charged a single time each on a Triton hobby charger. All reached 4.2 volts on that high quality charger so I know that these new (and even used) batteries are more than capable of reaching 4.2 volts, and that it's more-than-likely a problem with the Pila charger. Here's the readings:


New AW Protected 18500: 4.14, 4.16, 4.14, 4.17v

New AW 18650 2600mah: 4.16, 4.16v

Used (maybe 5-10 charges through each) AW protected 16340: 4.11, 4.04, 4.07v

AW IMR16340: 4.11, 4.07, 4.1, 4.09, 4.09, 4.14, 4.07

Something seems really wrong with my charger as well and I'm going to contact Pila, and let the store I bought the charger from know what they say (i.e. my unit is defective and needs a replacement or what).


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## Ziemas (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



TriChrome said:


> I think you're lucky to even be getting a constant 4.17 volts on this charger. I personally think it's either a POS, or something else I'm not aware of is up. I also bought into the "Pila IBC charger is the best on the market bar-none" mantra, and I'm now second guessing what all the hype is about.
> 
> Here's my readings on 16 freshly charged batteries. I'm completely new to reading voltages but I've read about 10 threads on here about how to do it, and bought a $50 Sperry autoranging multimeter to measure the voltage (measured right off the charger, positive probe in V omega terminal, negative in COM; unit switched to V (voltage) with a line and 3 dots above it).
> 
> ...


Also check your DMM as it might be off too.


----------



## ky70 (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Recdna, I likely know less about this stuff than anybody who has posted, but the question about the accuracy of your DMM seems an important factor, as you can not assume your DMM is reading spot on just because it measured batteries coming off your wf-139 @ 4.2v...unless you have other DMMs to use as a reference, there is nothing to confirm that your 4.2v reading (and consequently your 4.17v reading of batts off your Pila) is accurate. It could be low or high (or spot on) but based on what I've read in this thread, that's not known. 

Good luck though in finding the answers you seek as I share your frustrations with grasping a working knowledge of the technical aspects of li-on batteries and such.


----------



## TriChrome (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Ziemas said:


> Also check your DMM as it might be off too.


How would I do that?

If it helps, I measured the voltage of a slightly used Surefire CR123A and it was 3.12 volts. I can also trick my Triton hobby charger into giving me voltage readouts to the hundredth of a volt so I'll compare that when I can.

Is there also a DMM setting to check resistance to see if the cells are damaged in some way, which would make the Pila IBC charger terminate the charge before 4.2 volts (sorry to but in on your topic RecDNA).


----------



## olephart (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Lets flog a dead horse hoping we can stop basing decisions and making definitive statements on tiny voltage readings from random multi-meters.

Take a decent 3000 count meter with accuracy specs of 1/2% (.005) + 2 counts at 4.2V DC. What can you expect ?

4.2V x .005 = .021 + .02 = +/- .041V stated accuracy range.

If ya measure something at 4.18V, it could be anywhere between 4.139 and 4.221 and the meter would be in spec. Most any meter is likely to be better than this when it leaves the factory with fresh batteries. How long it maintains it and the actual accuracy is unknown. It may be less accurate due to:

Low internal battery voltage.
Fudging on specs. (Shocking)
Cheap out of spec components.
Temperature
Change in component values over time.

As a hobby guy, I would assume that most inexpensive meters will be +/- .03 and get on with more important things. If I saw charger terminating at values above 4.21 or less than 4.17, I'd probably want to check it out with a different meter before calling the voltage police. Note, I'm talking about termination V, not what the battery reads when removed.

If ya want/need .01V accuracy on a budget, all is not lost. Find a shop/person that has a new or recently calibrated (within a year) meter capable of +/- .01V, or less. Should be plenty in most areas. Grab a handful of batteries covering a range of voltages. Measure them with both meters noting the difference. Apply the difference to your raw readings. Use fresh batteries in your meter for the test and whenever critical measurements are required. Repeat every year, or so.

Just for fun, here are specs on fluke 175 and 179 meters. There are other meters for less $$ with similar or better specs.

F175 - 6000 count .0063 + 2 = +/- .0083 @ 4.2V
F179 - 6000 count .0038 + 2 = +/- .0058 @ 4.2V

Due to the 6000 count, the +2 count is added to the .000 digit instead of the .00 digit on the less expensive 3000 count meters. Makes a lotta difference.


----------



## Ziemas (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



TriChrome said:


> How would I do that?
> 
> If it helps, I measured the voltage of a slightly used Surefire CR123A and it was 3.12 volts. I can also trick my Triton hobby charger into giving me voltage readouts to the hundredth of a volt so I'll compare that when I can.
> 
> Is there also a DMM setting to check resistance to see if the cells are damaged in some way, which would make the Pila IBC charger terminate the charge before 4.2 volts (sorry to but in on your topic RecDNA).


You can check it against a calibrated meter or a calibrated source.


----------



## TriChrome (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



olephart said:


> Lets flog a dead horse hoping we can stop basing decisions and making definitive statements on tiny voltage readings from random multi-meters.


But those tiny voltage readings can add up to a loss of about 20% of battery capacity... when my HO-M6R only gets 14 minutes of runtime in my Surefire M3T, every minute counts.

I can also only speak for myself, but even if my DMM was off by more than the +/-0.5% its manual speaks of, I would expect it to read the same amount off nearly every time (especially when the batteries are read right after one another). My voltage range is from 4.07 to 4.17 which is quite drastic, especially considering the batteries are brand new, as is the DMM.

...might the fanboys be wrong, and this charger isn't as great as it's been made to sound?


----------



## Russel (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Ziemas said:


> You can check it against a calibrated meter or a calibrated source.


 
Low cost Voltage References


----------



## calebra (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



TriChrome said:


> I think you're lucky to even be getting a constant 4.17 volts on this charger. I personally think it's either a POS, or something else I'm not aware of is up. I also bought into the "Pila IBC charger is the best on the market bar-none" mantra, and I'm now second guessing what all the hype is about.
> 
> Here's my readings on 16 freshly charged batteries. I'm completely new to reading voltages but I've read about 10 threads on here about how to do it, and bought a $50 Sperry autoranging multimeter to measure the voltage (measured right off the charger, positive probe in V omega terminal, negative in COM; unit switched to V (voltage) with a line and 3 dots above it).
> 
> ...


i wouldnt be blaming ur charger where AW cells are concerned, i find them to be all over the place using a hobby charger, no less, as compared to pila batts off the same charger.


----------



## Bullzeyebill (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Ziemas said:


> You can check it against a calibrated meter or a calibrated source.



Bought a calibrated source. 5.0001V at 72 degrees. My Cen-tech P37772, 3000 count, shows 5.00, 72 degrees ambient temp. Now most people won't want to do that, but it sort of helped me make a decision not to jump on a Fluke for awhile, and doing this stuff is fun for me, flashlights, bulbs, LEDs, batteries, DMM's, etc. What CPF is about. Makes me sort of feel better about my Li-Ion cells, and their chargers.

Bill


----------



## 45/70 (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



TriChrome said:


> ...might the fanboys be wrong, and this charger isn't as great as it's been made to sound?



Let me point out that the reason the Pila has "fanboys" isn't because it charges to a certain voltage. The Pila charges to 4.20 Volts +/- 0.05 Volt, which is the specification for the charging of LiCo Li-Ion cells.

The reason the Pila is favored among consumer type Li-Ion chargers, is that the algorithm it uses comes closer to what the Li-Ion cell manufacturers recommend, than any other charger in this class. Voltage really doesn't have anything to do with it, as long as it's within spec.

Too many people are over concerned with voltage, and not paying attention to what really matters, in my opinion, which is how the cell is charged and what happens after that (ie. charging should stop, with no trickle charge). Just because a charger charges a LiCo cell to 4.15-4.25 volts, doesn't mean it's a good charger. The point is moot, if it screws up your cells and presents possible hazards doing so.

Dave


----------



## Mr Happy (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



TriChrome said:


> But those tiny voltage readings can add up to a loss of about 20% of battery capacity... when my HO-M6R only gets 14 minutes of runtime in my Surefire M3T, every minute counts.


I suggest that 20% of capacity is not normally what 0.03 V corresponds to. For instance, here is a discharge graph of an 18650 Li-ion cell (the Sanyo UR18650F):







If we look at the 0.5C discharge curve as typical, it runs from 4.1 V at 100% remaining capacity to about 3.5 V at 0% remaining capacity -- a span of 0.6 V from full to empty, and steeper at the start. If we say that 20% is 400 mAh, then the voltage would have to be down 0.2 at the start to lose that much capacity. I would have to say from that chart that 0.03 V amounts to 100 mAh at worst.

Also, 14 minutes? The HO-M6R draws a little over 2 A, so a typical 18650 setup should give you more than 50 minutes of run time (see the 1C, 2.3 A discharge curve above). Something seems not quite right.


----------



## recDNA (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

My multimeter is a Fluke 73. I brought it into the lab and had one of the techs check it out. The meter is fine. I brought home his meter tonight to double check. He put a new battery in the meter for me because he said that can throw off the measurements as well. 

I just recharged 2 AW IMR123. Both measured 4.16 volts.

I'm not saying this means the Pila is no good but several people have been asking me about the meter so I thought I'd have it checked out. I use meters from the lab so I never even knew what brand it was although I don't think the Fluke 73 is their best model anyway. I was convinced the meter was good anyway because, as I mentioned earlier, I tested several new primaries of different sizes and all tested out at the right voltage. 

*I'm happy to have a safer charger* but I must admit I would be even happier if my safe charger charged new batteries to 4.2 volts. As several have said - this may extend the life of my cells anyway.

Hopefully we can put this thread to bed now...and since I'm on the east coast of the USA that's where I'm headed too!

Trichrome - please let us know what Pila says. THANKS!


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## TriChrome (May 19, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Mr Happy said:


> I suggest that 20% ... ... ... ... Also, 14 minutes? The HO-M6R draws a little over 2 A



I'm going by this generic chart:

4.2 volts aprx. 100%
4.1 volts aprx. 90%
4.0 volts aprx. 80%
3.9 volts aprx. 60%
3.8 volts aprx. 40%
3.7 volts aprx. 20%
3.6 volts aprx. empty for practical use
<3.5 volts over-discharged

Some of my cells are reading 4.07 volts which is something like 8X% (I am estimating, most likely down, to make my point of the charger on some cells being .13 volts off from the fully charged 4.2 reading which is quite a large difference).

For the runtime, the HO-M6R draws 2.1 amps, so since it's being run on the M3T body I mentioned, using 3x AW 550mah IMR16340 cells, that's 15.7 minutes runtime ( (550/2100)x60 minutes per hour=15.714 minutes). My real world timed performance gives me 14 minutes before the light noticeably dims.


----------



## Meterman (May 20, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Recently I made a comparison charging a Sanyo 18650 using my Pila IBC (4.16 - 4.17V) at one hand and a Bench Power Supply set to 4.200V, 4.220V and 4.250V respectively on the other hand. The CBA used for the graph I don't see at all to be a precision instrument, but for comparing similar things it is useful. 






Results:
Pila ......... 2226mAh 8573mWh
4.200V ... 2400mAh 9285mWh
4.220V ... 2436mAh 9454mWh
4.250V ... 2510mAh 9755mWh

The advantage in mWh when charging at higher voltages is even a little bit better than that in mAh - that's often forgotten.

Wulf


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## Bullzeyebill (May 20, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Meterman, was you PSU set for cc/cv?

Bill


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## Meterman (May 20, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Constant current was set to 1.000A and Voltage was set to either of the three given Voltages. Thus at first it works in CC mode until the Voltage is reached, then CV takes over and current tapers until I shut off manually at 30mA.

Wulf

EDIT: Here I used the small version *PL155* because of it's acceptable (acoustical) noise. Not a cheapo either: http://www.tti-test.com/go/npl/npl-spec.htm


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## recDNA (May 31, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

OK, so riddle me this...

One of my IMR123 batteries only charges to 4.08 volts on my Pila. The other to 4.16. Both were purchased on the same day and always charged together. This was their 6th charge. 

I decided to take my life in my hands (j/k) and put them on my WF-139 to see what would happen. Both charged to 4.20 volts. The 4.16 volt battery took 5 minutes to get to 4.20 The 4.08 v battery took 15 minutes to get to 4.20

Does this mean I should toss the battery that doesn't charge to 4.16 on the Pila? Should I simply be happy with 4.08 volts? Or should I just charge it on wf-139 to 4.2?

Why would it only charge to 4.08 on one charger and 4.20 on the other if it is defective?


----------



## kramer5150 (May 31, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*

I would just use the WF-139, so long as it behaves consistently. 4.2 is not over-taxing the cells. my 139 has not given me a hint of trouble in 18 months of regular use, capping off at 4.17V with all my cells.


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## Ziemas (Jun 1, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> OK, so riddle me this...
> 
> One of my IMR123 batteries only charges to 4.08 volts on my Pila. The other to 4.16. Both were purchased on the same day and always charged together. This was their 6th charge.
> 
> ...


Why don't you contact Pila? They are the ones who can help you the best. Maybe you have a defective charger.


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## recDNA (Jun 1, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Ziemas said:


> Why don't you contact Pila? They are the ones who can help you the best. Maybe you have a defective charger.


 

I have. They say it is within specs. Keep in mind it normally charges every battery to 4.16 or 4.17 volts. It is only this one battery that it refuses to charge over 4.08 volts. Many users have results similar to mine. I'd run a poll asking what level your Pila charges to and then list 5 different values but I think some might see it as negative or an advertisement or something. Oh the heck with it. I'm going to do a poll.

The real question I have is why THAT battery charges LESS than the other and then why on a different charger it charges to a normal level. I think it means there is something wrong with the battery. It may be, for example, that although charged to 4.20 volts (I checked this morning and it is actually 4.19 now) the battery has less capacity than the one that normally charges to 4.16

The next time I charge them I'll do it on the Pila again and see if it ID's and charges the batteries to different voltages again or if the slate is clean. I've marked the "odd" battery for identification in the future.


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## mr.snakeman (Jun 1, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



jasonck08 said:


> I just use a Turnigy Accucell-6. They are like $24+shipping @ HobbyKing.
> 
> With the voltage calibration you can adjust the final charging voltage. When i got mine it would only charge to 4.17 or 4.18v. Then I calibrated it a bit and can usually get it to termiante the charge at 4.20 right on the dot.


My Turnigy Accucell-6 does the same thing. How did you calibrate yours. Please show and tell.


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## Ziemas (Jun 1, 2010)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> I have. They say it is within specs. Keep in mind it normally charges every battery to 4.16 or 4.17 volts. It is only this one battery that it refuses to charge over 4.08 volts. Many users have results similar to mine. I'd run a poll asking what level your Pila charges to and then list 5 different values but I think some might see it as negative or an advertisement or something. Oh the heck with it. I'm going to do a poll.
> 
> The real question I have is why THAT battery charges LESS than the other and then why on a different charger it charges to a normal level. I think it means there is something wrong with the battery. It may be, for example, that although charged to 4.20 volts (I checked this morning and it is actually 4.19 now) the battery has less capacity than the one that normally charges to 4.16
> 
> The next time I charge them I'll do it on the Pila again and see if it ID's and charges the batteries to different voltages again or if the slate is clean. I've marked the "odd" battery for identification in the future.


Eariler you said that you contacted the seller and they said that it was within spec. Have you actually contacted Pila USA?


----------



## recDNA (Jun 1, 2010)

*Re: Pila Charger Voltage Questions*

I just called Pila on the phone in Ohio. Only guaranteed with Pila batteries. He said some chargers will charge other brands to 4.2 and some to 4.16 or any value in between but random chance which one you get.

I'm tempted to try some Pila batteries. The Pila rep told me a chip in the battery communicates with a chip in the charger to ensure the perfect charge. Sounds good to me. Of course Pila batteries are expensive though. If it is the safest possible combo it's worth it.


----------



## 45/70 (Jun 1, 2010)

*Re: Pila Charger Voltage Questions*



recDNA said:


> I just called Pila on the phone in Ohio. Only guaranteed with Pila batteries. He said some chargers will charge other brands to 4.2 and some to 4.16 or any value in between but random chance which one you get.



An interesting response, not unlike I might expect. 

rec, I think you are still too hung up on attempting to charge your cells to 4.20 Volts. 4.20 Volts is nothing more than the midpoint between the 4.20 Volts +/- 0.05 Volt recommendation for LiCo Li-Ion cells that are in good condition (note that this voltage often cannot be obtained with used, or old cells, when using a proper CC/CV charger). It is handy if you have a charger that, in fact does charge to this voltage, as it makes it somewhat easier to determine cell condition etc.

The problem is, that the only way to guarantee an end of charge voltage of 4.20 Volts, is to use a CC (or variation thereof) charger that samples cell voltage and terminates the charge when the _actual cell voltage_ is 4.20 Volts, such as the WF-139. This type of charging algorithm utilizes a higher voltage to achieve this, and is not recommended because it can contribute to cell damage. 

A CC charger with voltage sampling, will charge a cell to 4.20 Volts no matter what the condition of the cell is, it will just keep charging the cell until the termination voltage is reached. This is potentially bad for LiCo cells, especially older and, or damaged cells. Any time spent charging a cell beyond where a proper CC/CV charger would terminate the charge (0.10-0.03C, _where "C" is charging current, not cell capacity_), causes oxidation of the electrodes, and damage to the cell.

As for why some of your cells will not charge to an acceptable voltage, I can't answer that. I don't believe that "forcing" a LiCo cell to 4.20 Volts will really tell you much however, other than you should be able to see a voltage drop after the cells rest for a bit, giving you an indication of their approximate condition. With IMR cells, I have no idea if this even works, as I have zero experience with them. My only knowledge of IMR cells is what I've read here on the Forums, and I don't remember ever seeing a way to determine IMR cell condition using rested voltage after charging, as an indicator.

Dave


----------



## recDNA (Jun 1, 2010)

*Re: Pila Charger Voltage Questions*

I said the charger is within manufacturer's specs. A poster repeatedly asked me to contact the manufacturer suggesting my charger may be defective. Finally I did and reported the content of the call. How do you discern from this sequence that it is I who am "too hung up" on 4.2 volts?


----------



## 45/70 (Jun 1, 2010)

*Re: Pila Charger Voltage Questions*



recDNA said:


> How do you discern from this sequence that it is I who am "too hung up" on 4.2 volts?



I wasn't referring to your having called Pila. The response you received was, as I said, anticipated.

What I was referring to is the fact that you tried to charge the under voltage cell in another charger to try and get it to 4.20 Volts. As I said in my last post, just because a charger charges a cell to 4.20 volts, when the Pila won't, doesn't mean that it's a good charger. More than likely, it means it isn't, although can still be useful. Perhaps I misunderstood your intentions, and you were just trying to see what happened.

Dave


----------



## mdocod (Jun 4, 2010)

*Re: Pila Charger Voltage Questions*

The best way to create a scenario where the Pila Terminates a particular cell abnormally lower than other cells (like that 4.08V vs 4.16V deviation) is to create a scenario where you have higher resistance in the path from the charger to the cell. This can be the cell itself, or the end-caps on the cell, or the rig used to adapt to the 16340 size cell in that charger, or a little of everything combined.

The WF-139 terminates based on open circuit voltage of the cell, not charging current, so the WF-139s charging method will use whatever charging voltage is necessary to over-come that resistance until the cell measures ~4.20V open circuit. 

The lower termination voltage in the Pila of that single cell is an indication that something is different.... It's very likely that the Pila is actually the constant here, and it has created a scenario that points out a high resistance condition that may not have been noticed in another charger. 

Eric


----------



## was.lost.but.now.found (Jun 7, 2010)




----------



## mke67 (Feb 19, 2012)

was.lost.but.now.found said:


>


LOL!!! I AGREE...But highly informative. Looking for a charger for my vaping mod box.


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## loquutis79 (Feb 19, 2012)

recDNA, my WF 139 seems to charge my AW 18650 1300's both to 4.18 or 4.19. I don't get the spot on 4.2 on this charger. But when my Pila gets here [its in the mail now] I will probably use that charger all the time. Maybe a few percent less charge, but longer cell life and MUCH safer. Anyone can forget to pull the batteries at green at some point. 100% charge with the higher risk of venting with flames is not worth it to me. So I charge once every 3 days instead of 4. [or whatever]

I hope you don't look at the L/100km specs. for your car, or check the kilawatt savings per year on that brand new fridge. You will be one unhappy camper.

I say, just enjoy your flashlights and the safer Pila charger. Life is short.

P.S. But I do understand your point about product specs. Its not a fair world.


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## NathanF (Mar 4, 2012)

I just got my new Pila charger from Bug Out Gear, and I have to say I'm not super impressed. I just put in two brand new Redilast protected 18650's, and fresh off the charger one is 4.14v and the other is 4.135v. This is as measured with my Fluke 179 True RMS meter.


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## SilverFox (Mar 4, 2012)

Hello NathanF,

Are you not impressed with the charger, or are you not impressed with your cell + protection circuit combination...?

Remember that all three play a part in the charging process.

Tom


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## NathanF (Mar 5, 2012)

SilverFox said:


> Hello NathanF,
> 
> Are you not impressed with the charger, or are you not impressed with your cell + protection circuit combination...?
> 
> ...



You make a good point, though it seems like many others have posted with similar results using similar batteries, now that I've read more up on it. I guess with all the accolades and the money I spent, I hoped to get a more or less "perfect" 4.2V charge, along with the assurance of a safe charge. Run time is very important to me, which is one of the reasons I shelled out more for the 3100 mAh batteries, and quality Panasonic cell based ones at that.

How does the math work out on capacity? If 4.2V is 100 percent charged, would 4.14V be 98.57 percent? Or is it not linear like that?

It's probably not worth worrying about.


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## SilverFox (Mar 7, 2012)

Hello NathanF,

The best predictive "guess" is that at 4.14 volts your cell is at about 94% of total capacity.

Tom


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## Joe Talmadge (Mar 7, 2012)

NathanF said:


> You make a good point, though it seems like many others have posted with similar results using similar batteries, now that I've read more up on it. I guess with all the accolades and the money I spent, I hoped to get a more or less "perfect" 4.2V charge, along with the assurance of a safe charge.



I guess the question is, if the charger forced a 4.2V charge even though that's contrary to the suggested algorithm -- hence possibly less safe and compromising battery lifetime -- is it still perfect? I guess the question that's not totally answered is, is this the Pila charging the battery to the exact right charge according to the algorithm (and the fault for the lower V result lies in battery internal resistance, protection circuit resistance, etc.), or is the Pila not functioning properly by mishandling the CV phase by a tiny bit? I'd guess the explanation is the former rather than the latter, but...

yes yes, I'm captain obvious


----------



## loquutis79 (Mar 8, 2012)

This is pretty much along the lines that I am thinking.

My brand new Maha C9000 seems to be able to do such wonderous things with NiMH, why is it so difficult to make charger which does the same for Li-ion. And the Maha was no more costly than the Pila.

[Silently thinking now...DOES the Maha do the same thing?]


----------



## tatasal (Mar 23, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*



recDNA said:


> Thanks Dave...although I don't understand all the technical reasons for your argument I DO get the point.
> 
> A far as battery degredation all of my batteries are AW and none have been charged more than 3 times.
> 
> ...




Yes, the issue is not what is the better termination voltage. If I buy a flashlight that claims so many lumens, only to step down after so many minutes, (WITHOUT DECLARING IT AS SUCH), then it will be of consequence. It simply cannot be justified later as 'safer' or whatever.


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## ElectronGuru (Mar 24, 2012)

NathanF said:


> Run time is very important to me, which is one of the reasons I shelled out more for the 3100 mAh batteries, and quality Panasonic cell based ones at that..



Nothing here is as simple as the fuel gauge in a car. For example, one of the ways the 3100 gets more rated capacity is by 'allowing' a lower cutoff of 2.5v. But put it in a light with its own cutoff of 3.0v (for example), and you'll be loosing half a volt of capacity/runtime, not unlike a charger terminating at 3.7v.


----------



## 45/70 (Mar 24, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*

You guys are missing the point. There is no specification anywhere that states that a LiCo (or LiMn) cell should be charged to 4.20 Volts. What you will find is a specification for maximum charge voltage. For the aforementioned cells this is generally 4.20 Volts +/- 0.05 Volt, or 4.20 Volts +/- 1%. This is the _maximum voltage_ to which these cells should be charged to.

A charger that uses a proper charging algorithm and happens to charge cells at exactly 4.20 Volts during the CV stage of the charge, will never be able to charge a cell to exactly 4.20 Volts. It is not possible. The cell may charge to nearly 4.20 Volts (eg. 4.195 Volts) if the cell is fairly new and a slower charge rate is used. On the other hand, if a faster charge rate is used, the cell may actually only charge to 4.15-4.16 Volts.

This is the nature of charging cells with a proper charging algorithm. Cells will only charge to a voltage which they are capable of accepting, without damage to the cell. Again, this voltage will vary depending on the charge rate used. Slower charge rates will result in higher end voltages, and faster charge rates will result in lower end voltages. Also, and this does not apply to cheap chargers, only chargers that use a proper charging algorithm, older, or more used cells will consistently charge to a lower voltage than newer cells.

A cheap charger that does not use a proper charging algorithm, often will charge cells to 4.20 Volts, or more. This is because these chargers charge cells at a higher than recommended voltage in order to achieve 4.20 volts at charge termination. These chargers mostly use a CC charging algorithm with voltage checking. This method of charging Li-Ion cells is damaging to cells, particularly older, or more used cells, as it forces them to a higher charged voltage than they would accept, if a proper CC/CV charging algorithm were used.

So again, if your charger consistently charges cells to the same voltage, eg. 4.20 Volts, regardless of charge rate, age of the cells, or how much they have been used, this is the sign of an inferior charging algorithm being used. This is why a $300 hobby charger will charge a newer LiCo cell to 4.15-4.19 Volts (depending on charge rate), and a cheap charger will charge the same cell to 4.20 Volts. The cheap charger is sending the cell to an early death.

This topic is one of the most misunderstood characteristics of Li-Ion cell charging on these Forums. Again, you will not find anywhere, from a reputable source anyway, a recommendation that LiCo, or LiMn cells be charged to 4.20 Volts. Also, take note that the difference in capacity of the same LiCo cell charged to 4.20 Volts, as opposed to 4.15 volts, is less than 5%. If for whatever reason your cell will only charge to 4.15 Volts using a proper charger, the extra 5% capacity that an inferior charger may add, isn't worth it in the long run, as the cell will see an earlier death.

Dave


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## Wreck3r (Mar 24, 2012)

I have been reading this thread with great interest and I would like to throw my 2c on this subject.

I recently purchased the iCharger 206B because I like the fact that it can be calibrated manually and works well with Logview. When I charged my first 18650 (AW 2900), I measured the open circuit voltage of the cell immediately after removing it from the charger. My DMM (Fluke 88460A) showed 4,185. 

I knew that my DMM was within specs so at first I was confused. But I think it's really simply why it wouldn't charge to 4.20.






As you can see, the CV stage starts at 4.20 and the termination current is C/10 which, again, is within the manufacturers standard charging cutoff.





This is the zoomed up version of the charging termination. So everything is according to manufacturers standards, the cell is new and the DMM confirms the log. The only thing that, in my opinion, is at fault is the cut off current of 50mA. If, for example, it went down to 0mA then the cell would have been 100% full, but also with its life shortened because of overcharging (according to the manufacturers guidelines).

There is another way of obtaining 4.20V open circuit voltage (fresh off the charger) and that is by using WF-139 algorithm - charging voltage higher than 4.20 but, again, this is not the proper CC/CV scheme.

Even though the voltage fresh of the charger is around 4,18, after discharging it to 3V with 0.2C discharge rate, it still has 2790mAh which is above the typical stated capacity.

Cheers

LE: Took a long time to source the logs and post and 45/70 beat me to it . But I'm happy to see that I shared the same thinking as you.


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## HKJ (Mar 24, 2012)

It might be easier to see the voltage drop on my curve here. The charge stops at the yellow line:


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## TEEJ (Mar 24, 2012)

Conceptually, remember that the REASON we test the cells so they don't have a DIFFERENCE, is BECAUSE 2 INDIVIDUAL cells might have different internal resistance. 

This is WHY we "match" cells for multi-cell lights.

Its not logical to therefore EXPECT that any 2 cells will, for some bizarre reason "HAVE TO BE IDENTICAL" when done charging.

IF they SHOULD be identical...then we would NOT have to check for "Matches", etc.

You can buy two identical models of a car...put the same gas into them, and one might get 22.1 mpg, and one might get 21.9 mpg. They BOTH get ~ 22 mpg, but the one that gets 21.9 mpg isn't "Broken", its just one one side of the normal expected production variation tolerance range...the the one that got 22.1 mpg is on the other. 

EXPECT a range of performance, EXPECT that two cells of the same age and make, etc, might be a little different...and the 100 cells of the same make/model will cover a RANGE of internal resistance values, etc.

To look at a 4.17 v vs a 4.19 v charge and think there's something "wrong" ignores this EXPECTED range of performance for those cells. Range Happens.


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## ElectronGuru (Mar 24, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*



45/70 said:


> There is no specification anywhere that states that a LiCo (or LiMn) cell should be charged to 4.20 Volts. What you will find is a specification for *maximum charge[r] voltage*.
> 
> A cheap charger that does not use a proper charging algorithm, often will charge cells to 4.20 Volts, or more. This is because these chargers charge cells at a higher than recommended voltage in order to achieve 4.20 volts at charge termination.




This may be the most salient point in this entire thread (emphasis added). 

Broken out:

1) there are two voltages, what the charger is pushing and what the cell reads (pushes back)

2) a cell cannot return as much voltage as is sent by the charger

3a) a charger pushing 4.2v will get back ~4.15v

3b) a charger needs to push more than 4.2v (like 4.23) to get back 4.2v

4) a charger must push more than (is specified =) 4.2 for a cell to give back 4.2.

5) a cell reading 4.2 has most likely been over charged


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## tatasal (Mar 24, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Looking at my Pila IBC manual now, in the Specifications section it says: IBC Charger DC out : 4.2 VDC / 600 mA x 2.
So with this raging brouhaha, perhaps Pila should revise this spec to include the gist of all your correct opinions so as to not 'displease' flashaholics cum statisticians, lawyers, accountants of electronic numbers? Anyway let's all have fun in all of these, missing the point or not! hahaha CHEERS !


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## TEEJ (Mar 24, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*



tatasal said:


> Looking at my Pila IBC manual now, in the Specifications section it says: IBC Charger DC out : 4.2 VDC / 600 mA x 2.
> So with this raging brouhaha, perhaps Pila should revise this spec to include the gist of all your correct opinions so as to not 'displease' flashaholics cum statisticians, lawyers, accountants of electronic numbers? Anyway let's all have fun in all of these, missing the point or not! hahaha CHEERS !



LOL

4.2 v out doesn't mean what you think it means.


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## Wreck3r (Mar 25, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*



tatasal said:


> Looking at my Pila IBC manual now, in the Specifications section it says: IBC Charger DC out : 4.2 VDC / 600 mA x 2.
> So with this raging brouhaha, perhaps Pila should revise this spec to include the gist of all your correct opinions so as to not 'displease' flashaholics cum statisticians, lawyers, accountants of electronic numbers? Anyway let's all have fun in all of these, missing the point or not! hahaha CHEERS !



It's a pity that you haven't read the posts above you. The conclusion will be that PILA doesn't have to do squat.


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## tatasal (Mar 25, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*



Wreck3r said:


> It's a pity that you haven't read the posts above you. The conclusion will be that PILA doesn't have to do squat.



More so Pila's customers doesn't have to do squat either! It's more of a pity you are missing my non-technical point...I perfectly understand your latest technical post...In fact I would have asked a new question regarding my Pila's charging output results if not for the post of 45/70, hkj, teej and you Wrecked, oops, Wreck3r.


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## Bullzeyebill (Mar 25, 2012)

*Re: Why Does My PILA only Charge to 4.17 volts?*

Let us keep it civil folks. Attack the post, not the poster.

Bill


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