# How to charge a 3400mAh 18650 cell?



## jawnn (Nov 19, 2014)

What voltage will the Orbotronic 3400 cell be at the 3.4 amps? and don't I need to charge it at that voltage? will a voltage regulator work? I intend to put the battery in a steel box while charging, because I do not trust them.


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## ChrisGarrett (Nov 19, 2014)

You need a dedicated hobby charger, or consumer lithium ion cell charger to charge up a li-ion cell, either cobalt, manganese, or phosphate.

Most of these consumer chargers, have charging rates from 250mA up to 2A, with many being between 500mA and 1A.

For a 3400mAh cell, a 1A charging rate is fine and typical. Some cells can be charged higher, say at 1.5A, or even 2A, although that's generally at the higher end of what we like.

Chris


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## NoNotAgain (Nov 19, 2014)

I'm confused?? What are you attempting to do? If you are just attempting to charge s set of batteries, most chargers limit current to under 1 amp for the charge duration. They use a voltage cutoff of 4.2 volts.

My Nitecore d4 charger, charging 4 3400 mAh batteries, will only produce .375 mAh for each cell. Nitecore digital chargers monitor current, voltage and I believe temperature, though they don't come out and state temperature.


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## okashira (Nov 19, 2014)

jawnn said:


> What voltage will the Orbotronic 3400 cell be at the 3.4 amps? and don't I need to charge it at that voltage? will a voltage regulator work? I intend to put the battery in a steel box while charging, because I do not trust them.



Max applied voltage should be ~4.2v. However, when the battery is depleted, you need to limit current during charging.
When voltage is low (charge when cell is at ~2.9V) apply ~1A, until voltage reaches desired charge voltage, then taper current until current reaches 50-100mA.

Recommend using 4.10 - 4.15 charge voltage to extend cell life.
Resting voltage (60 minutes after removing from charger) should be ~4.085 - ~4.135, or ~4.185 if you desire the full 4.2V charge.


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## jawnn (Nov 19, 2014)

Thanks this is good info. I made the mistake that I could get more than one hour from a Nitecore rc20 with a above mentioned battery. so now I am going to have to use two or three cells in pack. Wire sticking out the back for Bicycling.
I do have one of those smart chargers, but it is only good for unprotected cells and I do not know if it even works at all.

*Do you think the Orbtronic batterys are reasonably safe?


what is the difference between a charge and a voltage regulator? do the cheap ac chargers slow down at the end of the charge while the voltege regulator will not?*


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## NoNotAgain (Nov 19, 2014)

The only outward difference between a protected and unprotected cell is the protected cell is slightly longer and the circuit is sometimes visible. 

If you have a DMM you can monitor the initial charging to see if the charger works. If there is a concern of malfunction, place the charger outside in a protected area a frequently check on it. 

The Nitecore d4 charger is on sale at illumination supply for $20.50. They also have a two cell version for around $13.00. 

Don't remember if illumination supply or battery junction is the company that sells lithium ion packs, but that might be what you need.

Orbtronic cells are fine.


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## hiuintahs (Nov 19, 2014)

jawnn said:


> What voltage will the Orbotronic 3400 cell be at the 3.4 amps? and don't I need to charge it at that voltage? will a voltage regulator work? I intend to put the battery in a steel box while charging, because I do not trust them.



Ahhh, you are getting your definitions mixed up. The 3400mAh (mili-amp-hour) cell is capacity of the battery. It's measured in current multiplied by time. It means that if your battery if fully charged and you put a 1mA load on it.....it will last for 3400 hours. Or if you put a 1 amp load on it it will last for 3.4 hours.

A 3.7v lithium ion cell is to be charged up to 4.20v. The 3.7v is just a nominal title to the type of lithium ion battery it is, which is what I think your Orbtronic 3400mAh battery is. You want to use a charger meant to charge this type of battery and it takes care of everything for you and won't over charge it.



jawnn said:


> .........*Do you think the Orbtronic batterys are reasonably safe?
> 
> what is the difference between a charge and a voltage regulator? do the cheap ac chargers slow down at the end of the charge while the voltege regulator will not?*


Yes, the Orbtronic should be fine. I think yours is probably based on the Panasonic NCR18650B cell which is a good one. Post a picture on here so I can see it.

The lithium ion charge process is that it injects a constant current into the battery until it reaches 4.20v and then it holds that voltage as the current drops to about 10% of the original charge current and then it considers it fully charged.

If you are using a proper lithium ion charger, you don't have to be worried about terms like "charge and voltage regulator". Those are electronic terms that I think you are getting mixed up on with the lithium ion charge process....but are terms more related to power supplies. The lithium ion charger is a form of a voltage regulator but there is more to it than that.

Also it shouldn't matter to the battery charger if the battery is protected or not.


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## rwfishman (Nov 19, 2014)

Newbie here.
I'm a little confused! If I have a Nitecore i4 “2014 Edition” charger; Some Nitecore NL189 3400mAh Protected Rechargeable 18650 Batteries, and some ZL634 ZL634 3400mAh 18650 Protected Li-ion Battery, do I ever need to be concerned about charging them? I'll be placing them in ether a Nitecore P12, a Nitecore SRT7, or a Zebralight SC62w.
Thanks in advance for your answers.


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## ChrisGarrett (Nov 19, 2014)

rwfishman said:


> Newbie here.
> I'm a little confused! If I have a Nitecore i4 “2014 Edition” charger; Some Nitecore NL189 3400mAh Protected Rechargeable 18650 Batteries, and some ZL634 ZL634 3400mAh 18650 Protected Li-ion Battery, do I ever need to be concerned about charging them? I'll be placing them in ether a Nitecore P12, a Nitecore SRT7, or a Zebralight SC62w.
> Thanks in advance for your answers.



You need to be mindful around li-ions and hopefully have a digital multi-meter handy to check on your cells while you discharge them (or at least learn what they do after being on for an hour, or two.) You'll want to measure the voltage of your cells hot off the charger, then perhaps in 20 minutes time, just to confirm that your NiteCore charger is not overcharging them.

I don't know what the difference is between the 3400mAh NL189 and the 3400mAh ZL634, but they're protected and they should be fine in your lights, assuming that they fit in the first place?

With a little bit of attention to detail, li-ion use in our hobby is quite safe, but not without a caveat.

Chris


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## rwfishman (Nov 19, 2014)

HI Chris,
When you say "discharge them" what exactly do you mean? Are you referring to them being used in the flashlight, or do you mean something else?
Thanks,
Randy


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## ChrisGarrett (Nov 19, 2014)

rwfishman said:


> HI Chris,
> When you say "discharge them" what exactly do you mean? Are you referring to them being used in the flashlight, or do you mean something else?
> Thanks,
> Randy



What I try and do is to, as best that I can, is learn my lights, my cells and my runtimes. 

Now, my brain isn't a stop watch, but I get an idea of how long I can run my lights on high, medium and/or low. This allows me to have at least a mental picture of where my cells might be after 30 minutes, or an hour, or two.

I'll run a light for 20 minutes, remove the cell and check the voltage. After a 10 minute rest, I'll repeat that and see where the cell's voltage is. When I get down to 3.6ish volts, it's time to charge it back up.

This way you're not blasting your light wily-nilly and having no clue as to what the cell is doing voltage-wise.

Chris


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## rwfishman (Nov 20, 2014)

Thanks for clearing that up. Can you recommend a decent digital multi meter? I went to Sears and Radio Shack and they were not able to be of much help so I didn't get anything.

By the way, the reason I bought Nitecore and Zebralight batteries is that was the only way I knew of to be certain my batteries would fit in their respective lights.
Randy


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## thedoc007 (Nov 20, 2014)

rwfishman said:


> Can you recommend a decent digital multi meter?



Search for "Innova 3320" on Amazon. Well reviewed, and since I own one myself, I can confirm it is simple, easy to use, and accurate. It is also under $20. No need to spend a ton for simple voltage checks. It also has an integrated battery tester for alkalines, if that is useful to you.


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## rwfishman (Nov 20, 2014)

Thanks again, Chris.
What type of 18650 rechargeable do you use? Do you use protected or unprotected? For now, I think it's better for me to stick with the protected batteries, but I'm curious.
Randy


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## mattheww50 (Nov 20, 2014)

Whether you use protected or unprotected cells generally depends upon the application. Protection means the cell will effectively open circuit if you exceed either the current limit, or the output voltage drops to low. In generally bad things happen with Li-Ion cells if they are either over discharged, or overcharged, hence the need for a charger specifically designed to support whatever Lithium Ion Chemistry you are using.

In general, for applications that use a singe cell, protection is not needed. most devices simply stop working when the cell voltage fall to low. When there are multipe cells involved in the application, and especially if they are in series, you usually will want protected cells. The risk is that if the cells are not well matched, you can have one cell drop below the safe limit for discharge, while the other cells remain well above the cutoff voltage. That means the total voltage from the series cells may still be above the cutoff point for the device, even though a single cell is below the safe limit. If you use protected cells the protection will open circuit the battery to prevent further discharge when the voltage drops below the safe lower limit for the cell.

Most of the devices I own use multiple cells, so I use protected cells in them.


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## rwfishman (Nov 20, 2014)

Again, I have a lot of studying to do but you would think that if I'm using Nitecore's i4 Intellicharger 2014 Edition that the chemistry between charger and battery would be correct, and I should not have to worry about charging their (and Zebralight's) batteries (both are 18650 protected batteries).
I'm only using single cell lights now and I'm only using Nitecore batteries in Nitecore's flashlighs (and Zebralight in Zebralight). Probably a little over cautious.
A lot to learn, but I'm anal (and don't want to blow myself or anyone else up) so I'll do my best to learn and ask questions.
Thanks.


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## jawnn (Nov 20, 2014)

*How to fill a 3400 mAh cell to the maximum?*

yadayada yada....bla bla continued here: http://www.candlepowerforums.com/vb/showthread.php?393005-chargers-for-18650-cells

*Thread merge there's no need for a new thread - Norm*


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## jawnn (Nov 22, 2014)

*chargers for 18650 cells?*

please tell me about chargers. Are there any that I can program for a protected cell? 

I found this but no nothing about it. It does not look programmable, but is adjustable....?
http://www.adafruit.com/products/280

Maybe I need to remove the protection circuit from an 18650 and wire in a bypass to charge it with one of the RC chargers?? Then have the out put though the protection circuit.


But maybe there is a charger that will fill a 3.4Ah cell perfectly with no adjustments?


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## thedoc007 (Nov 22, 2014)

*Re: chargers for 18650 cells?*



jawnn said:


> But maybe there is a charger that will fill a 3.4Ah cell perfectly with no adjustments?



Just about any charger that will do a proper job for unprotected lithium-ion cells will also work for protected cells. The protection circuit is only there to make sure everything is maintained within spec (prevents overcharging, over-discharging, etc.) none of which will be needed if you have a decent charger. A few chargers might have issues with long protected cells...but that would be the exception, not the rule.

If you have some extra money to spend, take a look at the Xtar VP2. One of the best li-ion chargers out there, with support for multiple cell voltages and a nice readout so you can see the status.

If you are trying to get one for less, take a look at the Nitecore D2. Still a very nice charger, and as a bonus it will work for NiMH batteries too.


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## jawnn (Nov 22, 2014)

*Re: chargers for 18650 cells?*

very good.... but I ended up with a counterfeit i-Max that says it can not do protected cell.. maybe I should find one that says it can. Like the Hyperion* EOS0403i*....

well maybe it's way more than I need? But I do need something for packs as we4ll as the single cells. *Does that do a pack of protected cells?*


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## kreisl (Nov 22, 2014)

*Re: chargers for 18650 cells?*

i have original and counterfeit i-Max, both charge protected 3400mAh fine!


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## aryntha (Nov 22, 2014)

*Re: chargers for 18650 cells?*

Hmm, actually came on here for the same reason, looking for a really good 18650 charger. Haven't been around for a while, and trying to get back into the scene, here and on LPF. Been using the crappy TrustFire ones for a long time, and decided it's time to grow up - I've been looking at the Nitecore D2 or the Xtar VP2; is there anything that you guys would consider to be *better* than that?


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## ven (Nov 22, 2014)

*Re: chargers for 18650 cells?*

Imo the vp2 for a 2 bay charger is one of the best if not the best for the money. Many options from 3.2/3.6(4.2v) and 3.8(4.35v) cells,and 0.25/0.5/1A charge options too.
Nice display/read out of the V too..........
vp2 on left and vp1 on right(vp1 good value without a few extras including USB and 3.8v support)


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## tripplec (Nov 23, 2014)

*Re: chargers for 18650 cells?*

I just started looking for something that will analyses capacity of Li-ion as well. A quick look at the above chargers don't appear to.

I currently have a IQ-328 & Nitecore I4 and if I add another charge to my collection I'd would like with backlite display (a must) as well as cycling Li-ion family of cells while displaying their mAh, and end voltage along with other smart features. XP2 does no appear to do that although a good 2 cell charger.


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## thedoc007 (Nov 23, 2014)

*Re: chargers for 18650 cells?*



tripplec said:


> I just started looking for something that will analyses capacity of Li-ion as well.



Yeah, that will greatly limit your options. This is one of the few I know.


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## tripplec (Nov 23, 2014)

*Re: chargers for 18650 cells?*

Yes, I read that one a week or so ago.


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## trx430ex (Nov 23, 2014)

*Re: chargers for 18650 cells?*

Well I just had a Xtar Wp6 drop dead on me after 2 years of moderate use, is that a fair life expectancy?


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## rwfishman (Nov 23, 2014)

*Re: How to fill a 3400 mAh cell to the maximum?*

I've seen some comments on the need to use a LIPO bag. I understand that a LiPo is a certain type of battery pack. If I'm charging 18650's in a Nitecore i4 intellicharger should the charger be placed in this type of bag too? It seems that would help the charger to overheat.


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## thedoc007 (Nov 23, 2014)

*Re: How to fill a 3400 mAh cell to the maximum?*



rwfishman said:


> I've seen some comments on the need to use a LIPO bag. I understand that a LiPo is a certain type of battery pack. If I'm charging 18650's in a Nitecore i4 intellicharger should the charger be placed in this type of bag too? It seems that would help the charger to overheat.



You definitely don't need to use a fireproof bag when charging 18650s. That is over the line into paranoia...and as you point out, can create additional problems.


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