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Cellular NiMH battery pack; can they be charged directly ? Answered

I have some perfectly good Nokia battery packs from useless 5165 phones (Model "bms-2s").
They are 3.6 - 3.7V NiMH and have 4 flat copper contacts which 'make' with the phones by sliding on. The Phones have matching 'teeth' and happily 'smart' charge either these or the newer LI batteries.
(Clear pic here: http://www.jpldisplays.com.au/catalog/images/CPB-BLS2N.jpg )
I want to know if it is OK to simply connect the matching output from the charger across the +/- terminals (the 2 outer ones AFAIK...) and charge them directly ?

These work great to power LEDs and I already made a 5165 LED torch, but it was a pain to do and I'd rather just use the batteries naked.

Thanks for any info !



6 years ago

My last post indicates that I found my answer myself.
None of the replies were in any way helpful to me as far as answering exactly what I asked  about.

By very carefully stripping the plastic outer skins off of the Nokia packs I found they have little protectors in place, and so I left those connected.

I must emphasize the following:
At no point have any batteries that I've re-used leaked, gotten hot, caught fire, or exploded in any manner whatsoever.
There has been no hazard created or seen in this process.

It is my belief that when others harp upon a thing that someone else wants to learn about=> saying it is overly dangerous and prone to explosions and the like, those folks have over-active imaginations.
Here's what I mean:
I, personally, have seen maybe a dozen real, serious car fires in my life, and oddly enough - not one has exploded, ever.
That sort of stuff gets into people's heads from TV shows, I think.

I have found that re-using cellular batteries minus the phones and using their own chargers is a wonderful and cheap way to power small projects with very high quality batteries.


8 years ago

When working with high-energy battery chemistries -- NiMH and LiPO in particular -- you MUST! use a proper charging circuit. See "Related" at the right, specifically the "SAFE Recharging" item. Otherwise you risk the cells exploding, catching fire, or both -- and burning metal is nasty stuff.


Answer 8 years ago

The above answer does not come close to answering my question, sadly.
Using Nokia batteries with a Nokia charger would seem to be a self-evident testimony towards 'safety' though...yes ?
Most of my question was directed to whether the phone made the charger 'smarter' somehow - and the correct answer appears to be: NO.
I have connected 2 sets of these batteries in parallel via their circuit boards to a single Nokia charger as a supply for an LED spotlight and charged them for days on end.
No fires, explosions or even any excess warmth.
No overcharging either - and they stay charged incredibly well - it's been a month now that the improved light has been in my car with no charging and it is still just as bright as the day I put it in there.

Now - to further address the notion of 'burning metal':
I agree - hideous stuff - and I'll tell you that 30+ years ago I worked in a scrapyard that foolishly handled metal turnings; hundreds of tons in each pile.
Uncovered. Ferrous turnings, well oiled. Great.
When it rained they would catch fire sometimes - and NOTHING could stop that fire so it had to burn itself out.
The owners feared it would someday melt through the concrete of the dock upon which the yard rested - but that was not the BEST part...
Looming over the scrapyard were multiple storage tanks of LPG and LNG - enough so that if they caught fire the bay would be vaporized for a while and the cities on both sides would simply disappear instantly. (Of course, having the good fortune to be right there, us guys wouldn't even know we'd been vaporized...) The residents of said cities had exactly zero idea how they lived in the blast radius of such a bomb and a few times when (just for yuks) I tried to tell some folks about it - they simply refused to accept that I spoke truthfully.

My point in all the above:
We must learn to use and re-use what we have at hand and fear does not belong in that formula.

If Tesla and DaVinci and others of their genius had been as fearful as people are today they'd have sat in little rooms - too afraid to discover anything !!!

One must try - observe - test things when information is lacking.
BIG explosions really only happen on the TV and in the movies, mostly.


Answer 8 years ago

If you know what you're doing, great.

If you don't know what you're doing, caution (not fear, just knowing what you're getting into and whether you're really competent to handle it) is entirely appropriate.

Empiricists tend to suffer more injuries than necessary.


Answer 8 years ago

Please notice - neither of your postings here have even approached or tried to provide me with info useful in actually using and/or charging batteries.
THAT is what I was asking about.

I am not interested in discussing philosophies of experimentation with you - and being as I am well past 50 I suspect my philosophies are pretty well in place.

Also - I have suffered very few injuries from my doing and learning of tangible things in this life to date.

The worst injuries I have acquired in this life have been at the hands of other people - go figure.

I would appreciate if someone who understands how & if cellular phones work as 'smart chargers' could pitch in here - and please - no more high school safety lectures !!!?


Answer 8 years ago

Websearching "charging lithium batteries" quickly finds some descriptions of typical charging practice.

One example -- which I can't vouch for, but which sounds reasonable from what little I do know -- is http://www.powerstream.com/li.htm

Fast charging involves tracking cell temperature as well, if I remember correctly. (I know it usually does with NiMH. The manufacturers' descriptions of fast-charging NiMH are somewhat scary; they involve letting the cell build up a positive pressure of oxygen to drive one of the two reactions.)

Since I don't know how the Nokia battery terminals map to the contents of the battery pack, I can't say much more than that. This info is probably also on the web somewhere and obviously should be factored into your charger design.


Answer 6 years ago

Good Grief - time for an update here !!!
I've been re-using NIMH and LI packs with their original chargers, wired into different projects for about 3 years now.
There have been exactly ZERO fires - ZERO expl;osions, ZERO problems at all really.

In one thing I replaced a tiny lead/acid gel cel which was nasty with a couple of NIMH packs and they've been in daily use for about 2 years now, holding an excellent charge and giving good service.

All I ever did was to measure terminals for the rated battery voltage with my voltmeter and apply the charge THERE.

This is not a particle accelerator with superconductors and millions of volts - it is just wee battery packs for small projects.


Answer 6 years ago

Hi. Its been a while, but I just came to your post. I was wondering: So you're saying that you can connect original nokia charger to the pins of the nokia battery and it will be ok to charge it (without the phone)? I just want to make it sure, cos I'm gonna need this for my small led project:). Thanks.


Answer 6 years ago

Exactly what I've done and it works fine.
In fact I even re-did a bigger portable light from halogen to LEDs and used 2 of them wired in parallel with the same jack for the original charger and they charge together perfectly.

When I've re-used the LI batteries all I do is leave the battery pack intact with all it's protective stuff inside and solder directly to the correct terminals.

It's very easy and I've already done it for years with no trouble.

Best Wishes.