# Can you charge NiMH with higher Voltage setting? Short Answer: Yes!



## LuxLuthor (Mar 13, 2006)

I just got one of FiveMega's shorter Mag85 lights that use 9 x 2/3A 1.2V NiMH batteries in series (10.8V total) and am trying to figure out the best way to charge the pack with this $20 "Hitech" (model IC-14V) smart charger I bought from this website. (I'm trying to avoid buying a $120 Triton type charger, since this is the only thing I would need it for).

It has a voltage dial that correlates to the # of battery cells including 7 cells correlating with 9.8V; 8 cell setting = 11.2V; 10 cell setting = 14V, but no 9 cell setting.

Assuming that FM's pack of nine 2/3A (1.2V each) cells in the battery pack are in series to give 10.8V output, but Lexina said that these will each charge up to 1.4V (x9 = 12.6V) should I use the 8 cell charger setting of 11.2V or 10 cell setting of 14V ?

Lexina (in that FM topic) said: "I guess you could set at 10-cells but terminate the charge periodically and take a MM reading." I am wondering what would happen if I just let this smart charger run until the red (charging light) turns green (trickle) if I set it at 10 cell (14V).

It also has either 300mA or 600mA additional dial setting choice, so I'm assuming that should be at 600mA? 

Thanks for any advice.


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## wptski (Mar 13, 2006)

*Re: Need help with best charger settings please*

If it doesn't have a nine cell setting, that's it, it won't work, period. Your either undercharging or overcharging. You don't want to overcharge and damage the cells, correct? The ma setting would depend on the mAh rating of the 2/3A cells. If they are at least 600mAh, you could use that setting. If they are less, stick with the 300ma setting.


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## LuxLuthor (Mar 13, 2006)

*Re: Need help with best charger settings please*

Thanks for your note. These 2/3A are 1200 mAh. I have been searching google for 2 hours trying to find out what happens if you use a higher Voltage setting in a smart charger, like the 10 cell 14V with 9 NiMH cells that should be charged with 12.6V. I can't find anything about it anywhere.

I only got this cheaper charger after the owner of the battery site told me it would work with this 9 battery in series setup. I'm waiting to hear back from him about the setting.


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## LuxLuthor (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

I think it will be ok to use a 14V setting to charge the 9 cell battery pack that should be charged with 12.6 V, because when I look at this site, and particularly the graph on item 3.8.3, it appears that the charging of NiMH cells takes them all the way up to 1.55V and they quickly drop down to their resting 1.2V after about 30 seconds.

I figure the 9 cell pack x 1.55 V = 13.95V which is pretty close to the 14V 10 cell setting this charger has.


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## lexina (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

I think you would run a high risk of cooking the cells. When I charge my 7-cell pack using the same charger at the 7-cell setting, the cells become pretty hot towards the end of the charge just before the light turns green. After the light turns green, the pack can measure up to 10V (which is an average of 1.43V per cell). If you set the charger at 10 cells for a 9-cell pack and leave it until the light turns green, I am quite sure the cells will be damaged.

Perhaps you can do what jfrazier suggested in the Group Buy thread - set the charger to 8-cells and leave until the light turns green then reset to 10-cells. You should then periodically monitor the pack voltage and terminate the charge at around 12.6V - 12.9V.


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## Bob_G (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

Wouldn't it be easier to just bite the battery and get one of those Universal Smart Chargers for 30 bucks or so that everyone seems to be selling? Is there a reason one of these wouldn't work?


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## wptski (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

I never could find a maximum voltage vaule per cell either but I have a Sirius Pro Former and asked them what was the applied voltage/cell. They said 1.6V/cell.


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## LuxLuthor (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

The more I read about charging NiMH batteries, using 14V with 9 batteries (essentially 1.55 V per battery) should work fine. The heat is more related to the amount of current (mA) applied for faster charging. Using this GreenBattery.com charging time calculator with 600mA and 1200mAh NiMH batteries, gives 2.4 hrs charging time, or at 300mA 4.8 hrs. 

Using a higher current charging as a percent of the battery mA rating raises the heat, but shortens the charging time.

This Panasonic NiMH guide linked from Wiki says that the safe upper voltage limit per cell is 1.8V (see point 4 on first page).


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## wptski (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*



LuxLuthor said:


> The more I read about charging NiMH batteries, using 14V with 9 batteries (essentially 1.55 V per battery) should work fine. The heat is more related to the amount of current (mA) applied for faster charging. Using this GreenBattery.com charging time calculator with 600mA and 1200mAh NiMH batteries, gives 2.4 hrs charging time, or at 300mA 4.8 hrs.
> 
> Using a higher current charging as a percent of the battery mA rating raises the heat.
> 
> This Panasonic NiMH guide linked from Wiki says that the safe upper voltage limit per cell is 1.8V (see point 4 on first page).


That states if it reaches 1.8V/cell limit because of a problem not that it's a safe voltage limit.


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## LuxLuthor (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

Yeah, I understand...but my point is if they put a limit of 1.8V before it gets switched over from charging to trickle, that is yet another bit of information that charging in my case with a voltage of 1.56V per cell (14V/9cells) should not be a problem. I doubt battery manufacturers would allow batteries to blow up with a voltage of 1.6 or 1.7V even if applied for a full charge cycle, if they don't set their switchover limit until 1.8V.

I'm also thinking that if this charger is promoted as one that works with battery packs from 2 to 10 cells, and they don't have a select position for either 3 or 9 cells, then the next one up must be safe, or they would have had to exclude those size battery packs from the list.

I also have an email in with the Intellect Battery company to see if they have any advice. Worst case scenario, I buy a different charger...but I'm more using this as an opportunity about charging the various types of batteries. There are a lot of things I never knew, including a lot of things mentioned on this wiki link.

I had no idea about the flat state, damage from trickle charging, treating new batteries, etc. etc.


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## SilverFox (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

Hello LuxLuthor,

Keep in mind that most charging chips utilize a fail safe of 1.6 volts per cell. If the cell gets to that voltage, the charge terminates.

Most NiMh cells will show other charge termination signals at around 1.45 volts per cell.

You need around 1.8 - 2.0 volts per cell to charge, but I would not subject my cells to a voltage that high. The cells will probably take it, but will lose capacity and cycle life as a result.

Do you happen to have a link to the operators manual for your charger?

Tom


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## LuxLuthor (Mar 14, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

Thanks for the info.

No, I wish I did have a link. It is the Hitech IC-14V model that is on a number of websites, and is a company in China. I can't even find their home URL. I got it from this website

This was another resource - note Figure 5.8, which says like many other resources that the more typical charging voltage is 1.5-1.6V, but I have not seen any resources or specifications that say as high as 1.8-2.0V per cell is used for charging as you said. In fact, the Panasonic link above specifies their cutoff at 1.8V switching over to trickle as a safety measure.

This charger specifies a 1.5V charging output. This site has those smart chargers from the failed GB thread, and other types.


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## LuxLuthor (Mar 15, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

OK, I am now 100% sure that it is safe to use this $20 charger variable cell number dial setting of 14V (10 cells) for the 9 cell pack (1.56V/cell average) of 2/3A Intellect 1200 mAh NiMH batteries.

I have spoken with Greenbatteries.com and Thomas Battery company, and most importantly got an email back from Intellect battery company all saying that most all NiMH chargers use 1.4V to 1.5V (with variable amounts of mah current ranges), which is needed to bring the batteries to their NORMAL 1.4 to 1.45V initial charge reading, which falls to 1.2V within about 30-45 seconds.

They all confirmed that a slightly higher 1.56V is not a significant increase over the typical 1.5V, and some chargers likely have slightly higher voltage than their stated 1.5V output, but getting into the 1.70-1.8V range is not as clearly safe.


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## mdocod (Mar 15, 2006)

*Re: Can you charge NiMH with higher Voltage setting?*

If I were in your shoes- I would do like others have said, and run it on the 8 cell setting for awhile, then crank it to the 10 cell setting and periodically remove it and test the pack with a multimeter. I would remove it at ~13V personally.


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## LuxLuthor (Mar 15, 2006)

That's not a good idea because the 8 cell (11.2V) setting only charges the cells with 1.24V (11.2V/9) which is wayyy below the 1.5 that these cells need to be charged with to get the proper fast charge delta V drop. 

Again, most NiMH chargers use 1.5V per cell normally. Undercharging and long cycle charging of NiMH actually damages them.


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## wptski (Mar 15, 2006)

LuxLuthor:

Why bother to post the question if your going to go against the suggestions anyway?


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## LuxLuthor (Mar 15, 2006)

Well the thread started out as a question, since I had very little knowledge on the subject. I assumed there were people reading who would have expertise on the specific subject of the upper limit of safe fast charge voltage that can be applied to NiMH cells when I started, since there is little I could find with google on this specific topic.

Since then, I have spent about 5 hours reading, searching for engineering design specs of NiMH chargers, and talked to 4 expert people by phone. Most of the posts here were not based on the facts I have uncovered and given links to. 

For example the last suggestion of charging with 1.24V per cell demonstrates that they did know about the delta V charging peak graph needed to properly charge a NiMH before switching over to trickle. That suggestion can actually lead to damage of these type of cells which need high voltage and faster charging current cycles. Some of that is discussed at these two sites: http://en.wikipedia.org/wiki/Nimh_battery and Panasonic's pdf link here

As a result of doing my own research, I learned a lot about this specific topic, and can now correct incorrect ideas and suggestions. I doubt that anyone knows the actual maximum tolerated voltage for the Intellect 2/3A 1200mah battery that I got from the manufacturer as another example.


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## wptski (Mar 15, 2006)

LuxLuthor:

There link from one of those links to a Quest battery page that suggests against using -DeltaV as a form of termination! A majority of smart chargers use -DeltaV


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## LuxLuthor (Mar 15, 2006)

Bill, know what you mean about the Quest article under section 3.8.2.2 where they talk about using the ΔV of 3 mV once the battery reaches its "Peak Voltage," and how that is safer than using the -ΔV ("Negative Delta Voltage") which requires a longer high (fast) charge current be continued until there is more of a ΔV drop from the Peak Voltage of 5 mV. 

That is another example of the fine points in charging NiMH batteries that I have learned. I do not know if this $20 charger uses the ΔV of 3 mV once the battery reaches its "Peak Voltage," or the -ΔV ("Negative Delta Voltage") 5 mV longer drop method.


My whole reason for trying to find out about these issues initially was the cost savings of this $20 Intelligent Charger vs. a $125+ Triton type charger when I am only using it for this one FM flashlight mod. My DSD & AA/AAA MAHA chargers meet all my other battery charging needs.

_*Also as I mentioned earlier, if you look at the chart 3.8.3 diagram, you can see they draw the peak charging voltage PVD point at 1.57V which also supports my feeling that it is safe for me to use the 10 cell 14V setting for the 9 battery pack (14V/9=1.56V/cell). *_


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## wptski (Mar 15, 2006)

LuxLuthor said:


> Bill, know what you mean about the Quest article under section 3.8.2.2 where they talk about using the ΔV of 3 mV once the battery reaches its "Peak Voltage," and how that is safer than using the -ΔV ("Negative Delta Voltage") which requires a longer high (fast) charge current be continued until there is more of a ΔV drop from the Peak Voltage of 5 mV.
> 
> That is another example of the fine points in charging NiMH batteries that I have learned. I do not know if this $20 charger uses the ΔV of 3 mV once the battery reaches its "Peak Voltage," or the -ΔV ("Negative Delta Voltage") 5 mV longer drop method.
> 
> ...


LuxLuthor:

There are numerous RC type chargers out there like the Triton, Duratrax ICE, etc. that use cell count in their setup but there also some that don't like the Schulze 330d too. I would guess that there are more that do than don't! They want a cell count for some reason and it's not capacity in series!!


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## LuxLuthor (Mar 16, 2006)

wptski said:


> LuxLuthor:
> 
> There are numerous RC type chargers out there like the Triton, Duratrax ICE, etc. that use cell count in their setup but there also some that don't like the Schulze 330d too. I would guess that there are more that do than don't! They want a cell count for some reason and it's not capacity in series!!


 
Yeah, I have been looking at all the RC/Hobby websites and forums where they talk about all those chargers. Personally, I would not want to get a $125+ charger just for charging the 9 batteries for one flashlight. A number of those require 12 V power sources (Triton), and/or many have limits of 8 cells.

I know there are reasons for specifying the correct number of cells, but I have reassured myself with my reading and talking to the 4 experts that using a setting for a 10 cell pack in a 9 cell situation is not a significant issue. Even if this $20 charger uses the -ΔV ("Negative Delta Voltage") shutoff method, worst case is that I'll lose a little lifespan of the batteries. 

I also plan on using the timed formula of charging at 600mAh with these 1200mAh batteries of 2.4 hrs (145 mins)...so if it doesn't cycle off, I'll do it manually. I should get the light tomorrow or Friday, so I'll let you know how it works.


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## lexina (Mar 16, 2006)

maybe i am missing something. if the charger has a setting for 10 cells and you run it for 9 cells instead, surely it is going against the intention of the manufacturer and it is going to do some harm to the cells. you could do a timed charge as you mentioned but then it will be no different from using a dumb charger


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## wptski (Mar 16, 2006)

lexina said:


> maybe i am missing something. if the charger has a setting for 10 cells and you run it for 9 cells instead, surely it is going against the intention of the manufacturer and it is going to do some harm to the cells. you could do a timed charge as you mentioned but then it will be no different from using a dumb charger


I'm with you! 

I have a Sirius Pro Former constant current charger using for forming 1-8 Ni-CD or Ni-MH cells. It has selectable capacity range but no selection for the number of cells. It calculates that somehow! I just used it on eight new Ni-MH AA cells. The voltage applied was 12V or 1.5V/cell.


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## cmacclel (Mar 16, 2006)

Here is a REAL simple answer. If the charger has NO setting for 9 cells than DONT use it. Or you can sit there with your hand on the battery's while charging and a soon as they get warm there full. 


Mac


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## LuxLuthor (Mar 16, 2006)

Well, I'm happy to report that this $20 charger worked perfectly, and in almost the exact time frame it should have, based on the GreenBattery.com calculator formula here. They say it should have taken 2.4 hrs (2Hrs 30 Mins), and it changed to trickle at 2 Hrs 33 Mins.

I used the Intellect 1200 new batteries (after scotch taping the sides of each row of 3 to keep in a stack), which had an initial pack voltage reading of 11.7 V outside of the light. I put the pack in the light with a WA-1185 in one of FM's bipin ceramic holder, and ran it for about 5 mins until it dimmed significantly. Reading of pack now 10.9V.

I placed the charger dial in between the 8 cell and 10 cell settings, even though there was not a "click" when dial is put on one of the actual printed numbers. See this image of settings used.

I pressed the yellow "Discharge" button which changed diode to yellow, and drained it down to 10.3 V, and pressed discharge button again which turned diode red for Fast Charging mode.

I watched the Voltage carefully with multimeter every 3-5 minutes, and got reasonable readings at all times. Here at 30 minutes (12.52 V) then 13.00 V at 60 minutes then at 2 Hours up to 13.28 V.

It reached its Peak Voltage of 13.52 V (which is 1.5V per cell) at 2 Hrs 30 Mins at which time it finally got a little warm to the touch (not at all hot...only slightly more than a lukewarm feeling). I then watched the voltage drop down to 13.46 V (-ΔVof 6 mV) and at 2 Hrs 33 Mins, it tripped to Trickle Mode and I disconnected it after 5 more mins on trickle.

I let the batteries cool for about 10 mins, put them in the light and took an in socket reading of 12.82 V with switch turned on. I could not remember the voltage at which other people have been insta-flashing their 1185 bulbs, so I decided to wait another 20 minutes before turning on the light....and it worked perfectly with hellfire shining forth. No insta-flash of the bulb!!!

In summary, maybe there is some sort of variable rheostat voltage controller that allowed my half-way position of the dial to work for 9 cells, or maybe there is a sensing regulation and/or voltage tolerance of the cells and/or charger. 

All I know is the projected time frame it should have taken to charge the 1200mah cells with 600 mah setting accurately changed it over to trickle mode within about 5 minutes of when it should have. 

The temperature of the batteries never got hot, or even significantly warm, but there was a clear increase in the temp in the last 3-5 mins before it switched to trickle, and coinciding with the 6 mV voltage drop.

Based on the advice of the 4 experts I spoke with by phone & email, my own reading on the subject, and this actual MM testing during my first charging, I can verify that this method and $20 charger is a safe, economical option for those who do not wish to pay lots of money for more elaborate battery pack hobby type chargers (Triton, Duratrax, ICE, Promax, etc.). 

I got this Hitech charger (CBP-2-10CHG) from this site half-way down the page. I hope my notes in this thread are helpful to other users who may have bought this same light, but don't have a charger yet.


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## lexina (Mar 17, 2006)

good to know that the mid-way setting works - i have always wondered about that. thks.


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## LuxLuthor (Mar 17, 2006)

I was trying to think of a way to test for this half-way setting to be sure it was outputing voltage for 9 cells, but can't figure out how. I do know that if I put the MM in the charger's output leads it won't put out any measureable voltage or current.

I wanted to try this setting before doing the 10 cell adjustment, but I'm not curious enough to potentially screw something up just to prove that the 10 cell setting would also work. There is the same issue with not having a printed click slot setting for 3 cells. 

It made sense to me that they likely were using a potentiometer rheostat that rotated though the range of voltage adjustments, and even if there was not a "click" slot or printed setting for 9 cells, that the voltage position should still exist in between 8 & 10. Anyway, it worked perfectly.


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## cmacclel (Mar 17, 2006)

Lux it works and if supervised you should be OK but calling it "Safe" is kind of a long shot to me. 


Mac


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## wptski (Mar 17, 2006)

LuxLuther:

You read nothing on your meter because the charger checks for cell(s) before the charging starts. You may get away with this with Ni-MH cells but don't ever try this with Li-Ion or Li-Poly cells or you may be fighting a fire!

EDIT: Speaking of so-called experts! I once had a pulse charger for my cellphone batteries and called thier tech support about a problem. I was told to just remove the battery and reinsert it again. The charger "never" worked the same again!!


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## LuxLuthor (Mar 17, 2006)

*Mac*, wouldn't you think there is a variable potentiometer/rheostat that changes the voltage as you rotate the dial that would in effect give a reading of 9 cells halfway between 8 & 10 ? I'm not sure why you don't consider this safe, given how the voltage measurements, exact changeover time to trickle, and temperature all worked out.

I'm not asking to be argumentative, and I really do appreciate everyone's input. But this whole thing has been an interesting learning experience about various battery types, performance, charging, storage, etc. I just don't automatically buy the statements of "If it doesn't list the exact number of cells, don't use it."...without challenging the facts behind that assumption.

From all I read, there were also many forum stories in the various radio controlled hobby forums about people screwing up their chargers and batteries when using the more expensive Triton, ICE, and other sophisticated chargers as well. This $20 charger seemed to be as safe and "in specs" as anything I have read about for this exact purpose.


*wptski* -- Yeah, after reading about the issues of Li-Ion/LiPo charging, storage, and care....I totally agree with you on needing to be very careful and more conservative when dealing with them.

As far as experts....yeah I agree, and took them with a grain of salt, but when all 4 said the same thing, and gave technical Voltage specs of chargers and battery limits that they knew about, and when their advice was verified with a number of websites, I was fully prepared to charge at the 10 cell setting if what I tried didn't work.

This was yet another site that lists towards the bottom under building "The Ultimate Charger" item #5 using a safety manual cutoff when fast charging (at 1C) of 1.78V. Remember I was only charging mine with current rate of 0.5C (600mAh rate with 1200mAh batteries).

Again, thanks for everyone's input. Just because I am questioning what you have said does not mean I don't appreciate your input....I just wanted to challenge your points back to you and see if there were resource facts backing them up.


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## wptski (Mar 17, 2006)

LuxLuthor said:


> *Mac*, wouldn't you think there is a variable potentiometer/rheostat that changes the voltage as you rotate the dial that would in effect give a reading of 9 cells halfway between 8 & 10 ? I'm not sure why you don't consider this safe, given how the voltage measurements, exact changeover time to trickle, and temperature all worked out.
> 
> I'm not asking to be argumentative, and I really do appreciate everyone's input. But this whole thing has been an interesting learning experience about various battery types, performance, charging, storage, etc. I just don't automatically buy the statements of "If it doesn't list the exact number of cells, don't use it."...without challenging the facts behind that assumption.
> 
> ...


Who are your four experts and what chargers are they quoting spec on?

I have a Triton and DuraTrax ICE that have parameters for the number of cells installed, so I question anyone wanting to use a higher cell count than what's installed. Not becasue I know the reason why, just because I know that's the way it's normally done. I also have a Schulze 330d that doesn't have a parameter for cell number input on Ni-MH but "may" have for Ni-CD, I can't remember! I going to cycle some new Sanyo 2.7Ah cells that I just got so I'll make a note to record the input voltage on whatever I happen to use.


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## LuxLuthor (Mar 17, 2006)

Bill, I don't know if they are "experts" like electrical engineers who personally do the design specs for battery chargers, but they were all knowledgeable about NiMH voltage/current/temp/time for charging. Various ones by phone rattled off chargers they either had used or sold. 2 of them were ok with 1.56V, but said above 1.6V to charge got into a gray zone. 2 others thought that above 1.7V for charging was to be avoided.

Most of their answers started with ideally there should be a correct cell selection, but that most chargers use 1.5V or slightly higher, and going to 1.56V was not a significant increase. All were more concerned about mAh being used, especially to not go above 1C (1200 mAh in my case). When I said it only went up to 600 mAh, they all reassured me that 1.56 would be ok in this situation, three of them said to test while charging with MM as I did.

They were from phone calls and/or email to Intellect Battery (manufacturer of these batteries), Greenbatteries.com, Thomas Distributing (sells MAHA PowerEx batteries), Lees Hobby shop (local store that had Duratrax, Promax, & MRC), TowerHobbies.com, cheapbatterypacks.com (where I bought it, and willing to refund).

Most of them were more conservative than the 3 or 4 website links I have given in this thread of upper Voltage points at which fast charging should be terminated.

Didn't you say earlier that you found out that your Sirius used 1.6V to charge with? Also, how will you test the Voltage when you test those cells? I could only get the ongoing voltage that changed with time of the battery pack during charging, but not the output from the charger.


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## wptski (Mar 17, 2006)

LuxLuthor:

The Sirius people stated that it’s 1.6V/cell but with eight cells I measured 12V or 1.5V/cell while charging which is the only way to measure it.

Another point is the method you use to hold your cells. I have several Radio Shack 4/8 AA cell holders although they work for the mostpart I’ve run into problems where I will get a low capacity on my Triton or DuraTrax ICE during discharge. I have two adjustable clamps with heavy wire and Anderson Power Pole connectors that will hold two AA cells. I have another that will hold 4/8 AA cells using PVC pipe as a guide which has numerous holes for cooling.

I used the 8 cell RS holder and the Sirius Pro Former on eight 2.7Ah Sanyo AA. Discharged on the Triton for 2506mAh. A second time at 2589mAh. I connected it to the Schulze 330d in AutoC and the highest charge was only 600ma and that dropped to 290ma. I pulled out the large clamp. It always ramps up at the start but now went up to 4A and slowly dropped to 1.2A at around 11.2V. The last time I check it was around 700ma at 12V and had inputted 2.1Ah but I had restarted the cycle so I has another 230mAh added to that. This charger is very sensitive to cell connections!


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## LuxLuthor (Mar 18, 2006)

Bill, I'm not sure what all that means about how you hold cells as it applies to my situation. You completely lost me when you started talking about "two adjustable clamps with heavy wire and Anderson Power Pole connectors that will hold two AA cells. I have another that will hold 4/8 AA cells using PVC pipe as a guide which has numerous holes for cooling" I also have no idea what you were doing with apparently running discharging cycles with three separate chargers???

This was always just a simple project of using a simple El Cheapo $20 charger so I could get this one custom FM flashlight cranking out some Hellfire WA-1185 in a short Maglite. I do know that I would not want to use a battery charger like the Triton that has to use a 12V power source, since I'm not into any RC hobbies. AC power all the way for me in this situation, Baby!

I'm still not seeing how you can measure your charger output to know the Voltage output was 1.5V from your Sirius vs. them telling you it put out 1.6V per cell.


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## cmacclel (Mar 18, 2006)

Lux this may be a little of Topic but why even play with this cheap charger that you have to Mickey Mouse to work. In the last month you have spent like almost $2k on lights so why bother with a $20 charger?? Pick up a Triton or Ice charger there around $120 and will charge any battery you can throw at them. Also the condition the cells also. My new CBP 1650 cells after they where first charged only put out 750mah, after 8 conditioning cycles their up to 1500+ mah where they should be.


Mac


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## wasBlinded (Mar 18, 2006)

The important parameter during most of the charge time for NiMh cells is current, not voltage. If charging current is correct, voltage will be too. I think this focus on "charging voltage" is a red herring with NiMh cells (very important with Li-ion cells, though).

I suspect that a # of cells setting on a NiMh charger is important for two reasons - it knows how much negative delta V to look for (3 mv per cell for example) and it will set a "fail safe" voltage level that would only come into play if the charger did not detect negative delta V. The charge termination neg delta V for 8 vs 9 vs 10 cells is not different enough that the smart charger should miss the peak, though not having the right number set would probably increase the possibility of missing it, especially if the cells in the pack are mis-matched.


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## wptski (Mar 18, 2006)

wasBlinded:

The voltage parameter is there for some reason and I don't think that it should be ignored. The Schulze 330d adjusts the applied voltage in small amounts while keeping current the same during some portion of the charging cycle. As the current is lower the applied voltage increases towrds the end. Since the Schulze has a PC interface that graphs, I was going to post the graph form last night but "somhow" managed to lose it! If I don't lose the current one running, I'll post it later.

LuxLuthor:

I'll have to take a picture of the clamp, etc. and post it for you.

I just measure the voltage across the pack contacts while connected to the Sirius. I was charging eight cells and it read 12V, so it was 1.5V/cell. They told me 1.6V but it was lower.

I charged the eight cell pack twice with the Sirius and discharged it twice on the Triton. I then took the discharged pack and connected it to the Schulze 330d in its automatic charge cycle program. The cells were still in a RS eight cell holder. The Schulze wouldn't charge any higher than 600ma max and settled down at 290ma. I removed them from the RS holder and install them in my rigged with wires Sears adjustable clamp. Now having a better connection, the Schulze adusted the current as high as 4A and settled down to 1.2A for a majority of the charging cycle. Get it now? Pictures of the clamp and graph will help.

The PVC pipe is used to hold all the cells in line to clamp them. It's almost impossibel to hold eight cell in line and clamp them.


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## LuxLuthor (Mar 18, 2006)

*MAC:* My first contact with cheapbatteries.com after I bought the charger was to ask for a refund and get a better charger, and he was willing to do that. He also said that he was sure it would be ok, and if I wanted to try charging the Intellect cells also bought from him and if anything went wrong, he would refund that as well...so I figured I had nothing to lose...and it became more of a curiosity. 

As I began reading about the more elaborate chargers to buy, I knew I didn't want to screw around with also having to get a 12 V power source like the Triton requires. They were all so much more complicated and cost as much as the FM flashlight I wanted it for. There was enough about the cost, complexity, and limited use I had for one of those chargers that made me want to at least try a no risk Mr. Wizard experiment on this $20 charger.

Then it became fun and interesting to read about batteries, how to properly charge, condition, store, and learning what lifespan they had....which XeRay also suggested after I bought that spotlight. It became a learning experience. 

I now suspect I know as much or more about batteries than even most RC hobby users, whose forum discussions on battery technology are light years ahead of anything I have read here at CPF.

So to answer you question, I just really don't have a need for one of the more elaborate, expensive chargers. I can now use this $20 model to even condition and properly charge my AA/AAA batteries that I had been using in my MAHA model.

*wasBlinded:* I agree with you, as did the "experts" I spoke with. In fact 3 of them did say that the -ΔV of 3-5 mv changeover would work fine even if I had a higher applied voltage (1.56V) from the 10 cell setting. 

As this link explains, and confirmed by my phone calls, (read under the dT/dt versus -dV/dt section), when the batteries reach their maximum chemically stored charge, they begin to generate oxygen which heats up the battery and forces a drop in voltage as my testing confirmed. So I am sure that the higher voltage (1.56V) would have still resulted in the -ΔVdrop required to changeover to trickle because the oxygen reaction starts when the batteries are full, which forces the voltage to drop.

I might even try doing my next charge at the 10 cell setting and see if I get the same results.

*wptski: *So are you saying that the battery charging holders you use have poor contacts either because of electrical design, or inadequate physical contact pressure? Or is it somehow related to the holder having a certain amount of resistance that it interferes with necessary charger current/voltage getting from the charger to the batteries? Personally, I would dump any holder like that. 

In my setup, I simply put a piece of scotch tape along the sides of the three 2/3A size (1.2V NiMH) cells which gave me MM measured contact of each column, and then a tripled voltage when the 3 stacks of 3 were put in FM's holder.


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## wptski (Mar 18, 2006)

LuxLuthor:

Yes, the Radio Shack spring contact AA holders. I had better luck with the eight cell holders than than the four but the Schulze likes neither one. There must be some added resistance generated by the spring contacts. This could be why chargers have a solid spring contact and not the coil spring type. If so, what's commonly used in most lights? A spring type!


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## LuxLuthor (Mar 18, 2006)

If I was guessing....as with wire gauge, the thicker the wire (lower the gauge)...the better the current flow....and battery holders with a thin wire spring on the negative contact end would likely restrict current flow. I'm sure that's why battery chargers use solid metal contact strips.

Look at how thick the coil springs are in a typical size C/D Maglite as a way to resolve that higher current flow issue (vs. a AA size Mini Mag tailcap coil). Compare the C/D Maglite coil to your battery holder coil thickness for the answer there.


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## wptski (Mar 18, 2006)

LuxLuthor:

My 5W BB750 has a spring type contact and not that heavy and it draws 1.8A! I know that the heavier coil type spring on a MagLite will easily dent a "C" or "D" cell. I don't think that it's the size of the wire but the amount of pressure it puts on the cell in insure good contact.

Here's the graph from the Schulze charger with eight 2.7Ah Sanyo cells.







Here's the picture of the larger clamp holding the eight cell connected to the Schulze with soldered #12AWG wire and solid copper sheet using Anderson Power Pole connectors. Notice the PVC pipe which is a bit shorter the lenght of eight cells. This clamp will easily dent AA cells also. Those type of connectors come with a CBA-II, that's why I started using them on everything.


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## LuxLuthor (Mar 18, 2006)

LOL! Impressive custom setup....but that's way out of my league in terms of a setup to charge batteries.


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## wptski (Mar 18, 2006)

LuxLuthor:

Funny thing just happen, first time too. Switched to the Triton for a D/C cycle and that was going to be it, five cycles. It discharged 2509mAh but only charged 1000mAh! Cells seemed snug enough. Switch back to the Schulze but maybe I shouldn't now that I think about it. I'm running a discharge cycle now and see what happens. I should have just discharged with the Triton still!

I have a large number of chargers. That's a CC/CV power supply in the background which I use mostly for Li-Ion cells.

EDIT: I know what the problem was without looking. I forgot to reset the max capacity input. :mecry:


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## LuxLuthor (Mar 18, 2006)

LOL!....and MAC asks why I want to keep using my simple $20 special. Like I said, I read many many stories of people who had the Triton and many other fancy, expensive chargers and screwed up their batteries. They have more things to cause problems that I just don't need for this purpose.


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## cmacclel (Mar 18, 2006)

wptski said:


> LuxLuthor:
> 
> Funny thing just happen, first time too. Switched to the Triton for a D/C cycle and that was going to be it, five cycles. It discharged 2509mAh but only charged 1000mAh! Cells seemed snug enough. Switch back to the Schulze but maybe I shouldn't now that I think about it. I'm running a discharge cycle now and see what happens. I should have just discharged with the Triton still!
> 
> ...




Ha Ha I did the same thing!! I had no idea the triton had a MAX Mah input for Nimh cells.

Lux the Triton is a great charger and will give your cells longer life as it's charging algorithyms are much more advanced than the cheap chargers. Remember you pretty much get what you pay for.


Mac


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## wptski (Mar 18, 2006)

Mac:

Yep, it was set to 1000mAh, probably from the last usage on some AAA cells as I always set it a bit higher.


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## LuxLuthor (Mar 19, 2006)

cmacclel said:


> Ha Ha I did the same thing!! I had no idea the triton had a MAX Mah input for Nimh cells.
> 
> Lux the Triton is a great charger and will give your cells longer life as it's charging algorithyms are much more advanced than the cheap chargers. Remember you pretty much get what you pay for.
> 
> Mac


 
I can buy a lot of NiMH cells for $125, and I doubt the Triton algorithm will make that much difference for the cells I'm using after seeing my measurements with this $20 charger were right on the button. Plus I would have to also screw around with all the settings, and a 12 V power supply...and all the mistakes that I keep reading about being made just like this one with the Triton. 

If I was into RC hobbies, yeah I would agree with you...but for a flashlight it doesn't make sense to jump into the Triton league....even if I found an AC one that worked as well. 

My point in this thread was to see if this simple $20 charger would do the job *safely* without an apparent 9 cell setting, and I have answered that question. I can highly recommend it for others buying this FM flashlight GB using nine 2/3A NiMH cells, and not wanting to blow more than the cost of the light to charge its batteries.


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## lexina (Mar 19, 2006)

LuxLuthor said:


> My point in this thread was to see if this simple $20 charger would do the job *safely* without an apparent 9 cell setting, and I have answered that question. I can highly recommend it for others buying this FM flashlight GB using nine 2/3A NiMH cells, and not wanting to blow more than the cost of the light to charge its batteries.


 
I believe when you started this thread, you were trying to determine if it would be ok to charge a 9-cell pack in the 10-cell setting. Midway through, you became convinced that it would be possible and safe. However, in the end, you actually decided to charge your pack by selecting a setting mid-way between the 8-cell and the 10-cell setting - a Mickey Mouse job as cmacclel described it. So I guess, unless you are willing to try, we still do not have an answer as to whether it is ok to charge a 9-cell pack with the 10-cell setting!


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## wptski (Mar 19, 2006)

I thought that somebody mentioned this above but maybe not. Is it the maximum voltage per cell or cell count? If you set the voltage of the pack, you are setting the cell count. NegDeltaV looks for a mv/cell drop and if the charger calculates the wrong drop which it's looking for, that's not good. Like LEXIA mentioned, LuxLuthor ended up not setting his charger for 8 or 10 cell but 9 cells!


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## wasBlinded (Mar 19, 2006)

The difference in "looked for" -ΔV between a 9 cell pack and a 10 cell pack is pretty small and not likely to cause the charger to miss its charge termination signal, considering that a range from 3 mV and 5 mV per cell seems to be an acceptable range.


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## wptski (Mar 19, 2006)

wasBlinded said:


> The difference in "looked for" -ΔV between a 9 cell pack and a 10 cell pack is pretty small and not likely to cause the charger to miss its charge termination signal, considering that a range from 3 mV and 5 mV per cell seems to be an acceptable range.


Can you prove this? Are we back to the start again, where cell count and /or maximum voltage means nothing?


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## wasBlinded (Mar 19, 2006)

wptski said:


> Can you prove this? Are we back to the start again, where cell count and /or maximum voltage means nothing?


 
I can't prove it myself, any more than I can personally prove that the world is round. But here is a quote from http://www.batteryuniversity.com/partone-11.htm



> A nickel-metal-hydride charger must respond to a voltage drop of 8-16mV per cell. Making the charger too sensitive may terminate the fast charge halfway through the charge due to voltage fluctuations and electrical noise. Most of today's nickel-metal-hydride chargers use a combination of NDV, rate-of-temperature-increase (dT/dt), temperature sensing and timeout timers. The charger utilizes whatever comes first to terminate the fast-charge


.

Notice they say nothing about absolute voltage being used to determine end of charge. And, they give a range of from 8 to 16mV per cell for NDV. For a 9 cell pack, that is a range of from 72mv to 144mv. For a 10 cell pack that is 80mv to 160mv. There is a lot of overlap there! This is predicated on using a high charge rate so that there is a strong NDV when they are full.

There are also some "black box" NiMh chargers out there that claim to be able to smart charge different size battery packs, yet they have no setting for number of cells or voltage - only charge current. That suggests to me that they are looking for NDV and not paying much attention to charging voltages.


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## wptski (Mar 19, 2006)

wasBlinded:

Someone used that same quote from that Battery University page in another thread too! I'd like to see a list of today's Ni-MH chargers that use a combination of NDV, dT/dt, temperature sensing(??) and timeout timers?

I just don't "think" but I don't know for sure why manufactures would have a user input parameter that serves no purpose!

Now just so you don't think that I just like to disagree. I ran a test with my Triton. I discharged two old Radio Shack cells. I set it for three cells instead of two and the input capacity way high. These cells aren't marked anyway.

I connected a dual input temperature meter with two K-Type probes on the cells. I set it to 700ma rate. The voltage applied was 1.3V-1.4V range. I watched for awile but the temp was only 80F on the cells, so I felt safe to leave it. Thirty minutes later, it had terminated with 867mAh input.

It could be that cell count is only used for discharging plus the discharge voltage per cell and has no bearing on the charge cycle.

The one question I'd have now is, why do chargers that don't discharge have a cell count or max pack volatage then? Back to square one again!


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## LuxLuthor (Mar 19, 2006)

I resent my carefully controlled experiment with my $20 charger being characterized as "Mickey Mouse" when my results were right on the target of what should have happened. I think the comments are coming from embarassment that your 7-8 times as expensive chargers cannot do any better of a job for this isolated 9 cell charging regimen.

:lolsign: 
If anything is Mickey Mouse it is the failures of several using their sacred Triton chargers. Like many many posts in RC forums, you have screwed up your own elite battery charging....and despite those superb Triton algorithms.....hard to imagine, but welcome to Disneyland.

:wave: 

OK, now I have to defend the honor of my "little red engine that could," and I'll repeat the experiment tonight with the setting on 10 cells. Everyone was just guessing that the approximate 9 cell position was why I had the results I did. I'll find out.....stay tuned sports fans.

:touche:


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## wptski (Mar 19, 2006)

LuxLuthor:

I have "no" problem at all with using a cheap $20 charger and me using a Triton, ICE, Schulze, C210, C808M, C204W, C204FS, C777PLUS, C777PLUS-II and I may have left one or two more out! I don't care what kind of car you drive or how much your house cost either!

What problems are RC people haveing charging Ni-NH with a Triton? Some of those guys have more than one! There have been several fires charging Li-Poly packs with different chargers but you can't compare those to Ni-MH packs.

In your quest to use your cheap $20 charger, you've uncovered some information which for the most part is taken granted by many, including myself!

There still is the unanswered question, why does a cheap $20 that doesn't discharge have different voltage settings if it and cell count don't matter?


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## wasBlinded (Mar 19, 2006)

wptski said:


> There still is the unanswered question, why does a cheap $20 that doesn't discharge have different voltage settings if it and cell count don't matter?


 
Maybe its like the "Close Door" button on most elevators. :shrug:


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## lexina (Mar 19, 2006)

wptski said:


> LuxLuthor:
> There still is the unanswered question, why does a cheap $20 that doesn't discharge have different voltage settings if it and cell count don't matter?


 
Maybe this will contribute partly to solving the mystery but Luxluthor's charger (I actually have an identical one although under a different brand name) DOES have a Discharge function. You can see a photo of his charger from the 2nd link in post #25


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## LuxLuthor (Mar 20, 2006)

OK, gentlemen it is time to eat your lunches ! The poor little red engine that thought it could, thought it could....did the job perfectly. I gave him much praise and put him back in his box to get some sleep for such a nice job.

First of all, this much maligned $20 charger does have a discharge button, which I referred to in my last test. Secondly, this time I set the dial to 10 cells....DAMN THE TORPEDOES !!!

I drained the same light until it shut off, waited 5 mins turned it on to fade off again, then measured the starting pack voltage. 

Next I plugged in the $20 charger which just happens to come with the EXACT plug needed to make a connection with the FM battery pack, and press the DISCHARGE BUTTON which turns the diode yellow. Voltage drops to 10.14V, then AUTOMATICALLY changes to Fast Mode charging with diode now red.

All the pictures are listed below with times stamped on the images. You can blow them up and see the dial pointing to 10 cells, and the color of the diode, and Voltage reading on my MM. 

Basically it performed exactly as the previous time with the peak voltage briefly (15 seconds) of 13.57V and dropping to 13.52V when it trippped into Trickle Mode. Batteries never got more than the same SLIGHTLY WARM feeling. Time to Trickle mode: 2 Hrs 30 Mins.

Eat your hearts out all you who spent $150+ on your Tritons and 12V power supplies, because my little $20 red engine worked perfectly !!!

http://home.earthlink.net/~waterhole/charger-10/IMG_0001.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0002.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0003.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0005.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0008.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0010.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0013.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0017.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0019.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0022.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0025.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0026.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0028.jpg
http://home.earthlink.net/~waterhole/charger-10/IMG_0030.jpg


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## wptski (Mar 20, 2006)

lexina said:


> Maybe this will contribute partly to solving the mystery but Luxluthor's charger (I actually have an identical one although under a different brand name) DOES have a Discharge function. You can see a photo of his charger from the 2nd link in post #25


lexina:

It does have a discharge function! Great, my question is answered.


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## wptski (Mar 20, 2006)

LuxLuthor said:


> OK, gentlemen it is time to eat your lunches ! The poor little red engine that thought it could, thought it could....did the job perfectly. I gave him much praise and put him back in his box to get some sleep for such a nice job.
> 
> First of all, this much maligned $20 charger does have a discharge button, which I referred to in my last test. Secondly, this time I set the dial to 10 cells....DAMN THE TORPEDOES !!!
> 
> ...


LuxLuthor:

Doesn't bother me one bit! Sounds like your more upset about this than anybody else. Your tone is a bit on the nasty side.


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## LuxLuthor (Mar 21, 2006)

Oh sorry, I was just poking fun. I'm not upset at all...that's why I put the smilies in my post, and used the child's nursery rhyme of the little red engine that thought it could do it.

Here is my definition of a Mickey Mouse setup, which also worked great, but this is where I really need a higher mAh charging rate. I just wanted to make sure they got discharged which I have never done since buying these for my Archos MP3 player.

http://home.earthlink.net/~waterhole/mickey/IMG_0003.jpg


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## wptski (Mar 21, 2006)

LuxLuthor said:


> Oh sorry, I was just poking fun. I'm not upset at all...that's why I put the smilies in my post, and used the child's nursery rhyme of the little red engine that thought it could do it.
> 
> Here is my definition of a Mickey Mouse setup, which also worked great, but this is where I really need a higher mAh charging rate. I just wanted to make sure they got discharged which I have never done since buying these for my Archos MP3 player.
> 
> http://home.earthlink.net/~waterhole/mickey/IMG_0003.jpg



LuxLuthor;

I completely missed the humor!


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## LuxLuthor (Mar 21, 2006)

That's one of the problems with the internet, unless you know people separately! :rock: :laughing: 

In that lasty Mickey Mouse setup, I just used that to discharge the batteries, then put them in my old MAHA MH-C401FS charger. Man it takes forever to charge up 2500 mAh NiMH's.


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## wptski (Mar 24, 2006)

I just charged a DeWalt 14.4V Ni-CD pack which is 12 cells on a Duratrax ICE which has a 10 cell maximum at 1.5A, no problem at all! Cell count appears to mean nothing other than for discharging!


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## LuxLuthor (Mar 24, 2006)

Interesting info....and almost nothing about the voltage parameters related to the number of cells online. It all relates to charging current, or safety upper limits.

Hey, if I was to get an AC powered charger that I could use for Lithium Ion, NiMH, and maybe LiPoly....what would you recommend? I do not want to deal with a 12V power source for the Triton.


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## Handlobraesing (Mar 25, 2006)

The voltage shouldn't really matter with the NiMH chemistry, because the charger should be a constant current source. Automatic cell number detection works by pushing a constant current through the pack and measuring the open circuit voltage. 

For lithium ion and lead acid, having the exact voltage and current limit is critical. 

I suspect the only reason the charger needs to know the cell count is for setting the -dV value. So if its set for 8 cells, it might wait until it sees -80mV drop while in 10 cells, it waits until -100mV drop. If the charger can use temperature probe, it should matter even less.


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## wptski (Mar 25, 2006)

LuxLuthor said:


> Interesting info....and almost nothing about the voltage parameters related to the number of cells online. It all relates to charging current, or safety upper limits.
> 
> Hey, if I was to get an AC powered charger that I could use for Lithium Ion, NiMH, and maybe LiPoly....what would you recommend? I do not want to deal with a 12V power source for the Triton.


I think that you have only one choice, MAHA C777PLUS-II.


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## wptski (Mar 25, 2006)

Handlobraesing said:


> The voltage shouldn't really matter with the NiMH chemistry, because the charger should be a constant current source. Automatic cell number detection works by pushing a constant current through the pack and measuring the open circuit voltage.
> 
> For lithium ion and lead acid, having the exact voltage and current limit is critical.
> 
> I suspect the only reason the charger needs to know the cell count is for setting the -dV value. So if its set for 8 cells, it might wait until it sees -80mV drop while in 10 cells, it waits until -100mV drop. If the charger can use temperature probe, it should matter even less.


The Duratrax ICE "does" use -DeltaV for termination! It also has its own temperature probe input but it's not very accurate.


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## Handlobraesing (Mar 25, 2006)

wptski said:


> The Duratrax ICE "does" use -DeltaV for termination! It also has its own temperature probe input but it's not very accurate.



Then, its better for the batteries to use the lower setting even though it might result in a slightly premature cut-off. You won't damage the batteries by repeated premature charging. 

If it's an option, set it for lower cell count, then have it go into C/10 to C/30 rate trickle charge and top off for a few hours to achieve full charge.

Even if you skip the trickle charge and take it out right after the -dV cut off and say the pack is only charged to 80% capacity, it shouldn't be an issue for everyday use.


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## wptski (Mar 25, 2006)

Handlobraesing said:


> Then, its better for the batteries to use the lower setting even though it might result in a slightly premature cut-off. You won't damage the batteries by repeated premature charging.
> 
> If it's an option, set it for lower cell count, then have it go into C/10 to C/30 rate trickle charge and top off for a few hours to achieve full charge.
> 
> ...


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## LuxLuthor (Mar 25, 2006)

Handlobraesing said:


> The voltage shouldn't really matter with the NiMH chemistry, because the charger should be a constant current source. Automatic cell number detection works by pushing a constant current through the pack and measuring the open circuit voltage.
> 
> For lithium ion and lead acid, having the exact voltage and current limit is critical.
> 
> I suspect the only reason the charger needs to know the cell count is for setting the -dV value. So if its set for 8 cells, it might wait until it sees -80mV drop while in 10 cells, it waits until -100mV drop. If the charger can use temperature probe, it should matter even less.


 
Well the readings I took when setting the dial on 9 or 10 cells (for the 9 cell pack) show repeatedly that fast charge terminates with a drop of only 5-6 mV...which correlates with my "by touch" increase in temp of the batteries to a mild lukewarm range that was first detectable about 2-4 minutes before it auto-changes to trickle mode.

So I think it is only related to what wptski said about it being used for discharge. I just don't think it makes any difference with a lower or higher cell count from the voltage standpoint. All the things I could find as online references were only concerned with charging current, and upper limits of applied voltage not to exceed 1.7 to 1.8V (avg per cell)...and about the Peak Voltage and/or -ΔV involved in termination of fast charging. This was what 5 "experts" also told me by phone calls/e-mails I made.


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## LuxLuthor (Mar 25, 2006)

wptski said:


> I think that you have only one choice, MAHA C777PLUS-II.


 
Damn...this looks pretty impressive for only $69 !! Is there any downsides to it that keep it from being used for the same purposes as ICE or Triton...other than the fact that it seems to charge at a fixed current of "800mAh for NiMH & NiCD batteries and 400mA for Lithium Ion battery pack," but I can still deal with that by planning when to run the charge?


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## SilverFox (Mar 26, 2006)

Hello LexLuthor,

The only repeated complaint I have heard about the C777+II is that it often "cooks" NiMh and NiCd batteries and battery packs. This seems to happen even while using the temperature probe.

BentHeadTX has a current thread running where he is looking for a replacement for this charger because of this.

The Li-Ion side seems to work fine.

Tom


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## wptski (Mar 26, 2006)

The Duratrax ICE wouldn't allow me to charge at the wrong cell count but the Triton did! It took a few rounds as the capacity was increasing.

This was a 7.2V 2200mAh Ni-MH pack. I charged with a 6 cell setting and discharged with the same cell count but I charged at a 1 cell count but again discharged at 6 cell count. At a 6 cell count setting the capacity was 2288mAh and with a 1 cell count it was 2052mAh. A bit of a difference. I didn't pay any attention to the applied voltage at the different cell counts, probably shound have! :sigh:


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## TedTheLed (Mar 26, 2006)

what I do is have a dc power supply with two knobs that go from 0-3 amps and 0-30 volts.

I just hook up to a bunch of (similiar) batteries in their holders, turn up the voltage till the current flows, then turn it up a tiny bit higher, and set the appropriate current. When the voltage gets up to the voltage I set, it stops flowing..
Then I set the voltage a wee bit higher and feel the batteries every few minutes and terminate when warm, brown, and tender. 

I bought an analog unit (with needle gauges) wish I spent a little more for the digital for a more exact setting..

(kidding about the brown and tender)


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## wptski (Mar 26, 2006)

I have a HyTech CC/CV power supply but it's so touchy for setting the current. I tried it once and that was enough for me!


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## TedTheLed (Mar 26, 2006)

I got an EZ power supply -- it's..easy..and has been workijng for several years with no prob;

..as I said they call this a 'digital' supply but the scale is analog -- I'd get a digital read out next time around,

http://www.tequipment.net/EZDigitalGP4303A.asp


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## wptski (Mar 26, 2006)

TedTheLed said:


> I got an EZ power supply -- it's..easy..and has been workijng for several years with no prob;
> 
> ..as I said they call this a 'digital' supply but the scale is analog -- I'd get a digital read out next time around,
> 
> http://www.tequipment.net/EZDigitalGP4303A.asp


I payed about half of that for mine!


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## TedTheLed (Mar 27, 2006)

Wpt. -- so did I -- a few years ago.. but I can't find the place I got it. It was in New Jersey also..

Where did you get yours from?


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## LuxLuthor (Mar 27, 2006)

SilverFox said:


> Hello LexLuthor,
> 
> The only repeated complaint I have heard about the C777+II is that it often "cooks" NiMh and NiCd batteries and battery packs. This seems to happen even while using the temperature probe.
> 
> ...


 
LOL! I'm trying to picture what you mean by it "cooks" NiMH/NiCads. Sounds strange if the applied current is only 800 mAh...that is only 200 higher than my "Mickey Mouse" $20 charger....so I'm wondering why he would say that, unless his is defective. Thomas Dist. Co. & their PowerEx seems like a quality operation....so hard to imagine they would sell a battery charger that cooks and ruins batteries....but I'm a noob on this. I think for this price, I'll try it and see what happens. I also wonder if he is using their optional battery holders with it.


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## wptski (Mar 27, 2006)

TedTheLed said:


> Wpt. -- so did I -- a few years ago.. but I can't find the place I got it. It was in New Jersey also..
> 
> Where did you get yours from?


Off eBay but it might have been a store that sells on eBay too!


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