# Charging of non rechargeable batteries



## chop_tomatoe (Aug 19, 2013)

First of all statement:
I am aware of fire/explosion risk and i'm not recommending anyone to try to recharge non rechargeable batteries.

As some of you probably know, non rechargeable AA/AAA batteries can be recharged but it is not safe because chemicals inside can expand when get hot which may lead to explosion/fire.
Some guy on youtube charges them by setting power outlet to power on, power off every 15 minutes to avoid battery heating by using timer outlet.
That's how i want to charge my standard alkaline AAA's.
Only thing that bugs me is _how many amps and volts should i use and for how long time?
_




For those who wanna tell me to just buy rechargeable batteries - i already have them - sanyo eneloops and maha c800s charger, 



and i'm happy with it.
But i wanna try this.


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## Wrend (Aug 19, 2013)

I've tried this using basic "dumb" NiMH/NiCd 4 cell wall chargers, and it does work to a degree, but I won't really recommend it, because you only get maybe a 3 to 5 cycle reusable charge life from them (with significantly reduced performance), and I've found that their likelihood of leaking increases dramatically, to nearly 100%, if having them around for a bit.

So yeah, not really worth it, given the risks, and reduced performance. There are reasons you have your Eneloops, and one of them is so you don't have to bother with stuff like this, even though it can _kind of_ work. Why bother?


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## StorminMatt (Aug 19, 2013)

I should also note that, about 15-20 years ago, the 'next big thing' that was going to replace Nicad and NiMH was rechargeable alkaline batteries. But even though this technology was actually designed around being rechargeable, it was a flop (although I noticed that Fry's Electronics is still trying to push it). Capacity was less than normal alkaline batteries. This capacity was noticeably reduced with each recharge (especially if deep cycled). And the cycle life was somewhere on the order of 20-30 cycles - once again, fewer if you actually deep cycled your batteries. And if you were using them because you were on that 'can't use NiMH because I NEED 1.5 volts' kick, they typically would not charge to 1.5 volts (1.3-1.4 volts was more typical - less if you deep cycled your batteries). Not to mention that these batteries still had all the other shortcomings of alkaline batteries (such as high internal resistance and low current capacity). About the only good thing about them was that they didn't self discharge. So I wouldn't think things would be any better with alkaline batteries that are NOT designed to be recharged. Anyway, recharging alkaline batteries might be kind of an interesting thing to try as a kind of 'science experiment' to see whether it can be done. But as an actual means of saving money on batteries, it's just not practical.

One thing I should mention. Given the deep cycle performance (or lack thereof) of rechargeable alkaline batteries, it's probably best to try recharging alkaline batteries BEFORE they are completely dead. Or even close to dead.


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## Wrend (Aug 19, 2013)

> One thing I should mention. Given the deep cycle performance (or lack thereof) of rechargeable alkaline batteries, it's probably best to try recharging alkaline batteries BEFORE they are completely dead. Or even close to dead.



Good point. I had forgotten about mentioning that tidbit. I think I remember hearing that it's best to attempt to recharge them before they're half way depleted.

Also, about attempting to recharge them, you want a slightly higher voltage than recharging NiMH/NiCd to be able to push a charge into them and a lower maximum charging current rate due to their high charging IR and risk of overheating. I've heard that a faster current pulse rate is also recommended, such that you might get from a wall wart style PS/"dumb" charger.

Either way, if you do attempt this, be sure to keep a close eye on them.

I hardly use alkaline cells at all any more these days, let alone trying to recharge them, so take this for what it's worth.


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## IdRatherBeFishing (Aug 19, 2013)

I remember way back when we (my brother and I) had some radio controlled race cars that we got for Christmas from a really COOL "big box store" called Incredible Universe (sort of like what a Microcenter is today, only they had appliances, among other things, too). Along with the RC cars we got a full set of "rechargeable" batteries and a charger. I remember they were the alkaline batteries, and they were silver/gray in color. I think they were Incredible Universe branded sanyo's. I've probably got some around somewhere. 

I also remember that after racing those cars around for a while we were really fighting with them trying to keep them charged. 

All that having been said, taking about the charging cycle and that needing to be different than that of NiCd's or NiMh's, would it be worth a try to use one of the old alkaline chargers? If I knew where mine was I would give it a try if it still worked.. don't know where it could be though.


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## Wrend (Aug 19, 2013)

> ...would it be worth a try to use one of the old alkaline chargers?



I wouldn't bother with it. We've moved on to better batteries and chargers these days. (Well, holdouts excluded.)

It's interesting that it can be done (to a degree), but that doesn't mean that it should be done, especially when there are better alternatives.


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## Zorzi (Apr 11, 2014)

And especially when the chances of leakage increases...


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## Etsu (Apr 11, 2014)

As others have said, not worth it. However, I have done it several times just for fun. I've used a smart charger designed for rechargeable alkalines, as well as a dumb charger that uses lower current (250mA).

Of the two, I think the dumb charger does a better job. The smart charger tends to terminate the charging too quickly, probably because non-rechargeable alkalines don't react the same way that it expects from rechargeable alkalines.

With the dumb charger, I let it run for about an hour at a time, to prevent over-heating, then repeat a few times. Though, after an hour, the batteries still seem cool, so perhaps I'm just being paranoid.

With either approach, the batteries come off the charger around 1.6v, but after about a day of resting, they tend to settle at about 1.4v. I can't seem to charge them higher than 1.4v, even if I repeat the process to see if I can get more juice into them.

But it does work. You just need to be careful, and don't use them in anything of value in case they do leak. (Which is good advice for even fresh alkalines!)

I wouldn't charge them in series, though. Just use a regular charger and charge each cell independently.


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## mcnair55 (Apr 11, 2014)

chop_tomatoe said:


> First of all statement:
> I am aware of fire/explosion risk and i'm not recommending anyone to try to recharge non rechargeable batteries.
> 
> As some of you probably know, non rechargeable AA/AAA batteries can be recharged but it is not safe because chemicals inside can expand when get hot which may lead to explosion/fire.
> ...



Personally i would ban the posting all together as it could give inexperienced users the wrong idea,there is enough bogey man stories on here about batteries let alone this incredible stupid idea.


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## yellow (Apr 14, 2014)

they were called "RAM"-cells (ram battery)
... and - already mentionned - not worth the disadvantages


PS, aside from all already typed: 
not able to give the current needed


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## MarioJP (Apr 14, 2014)

Oh, I remember those days. "Renewal reusable alkalines". I sure fell for their ads. They only had 25 cycles and be lucky if you ever get to 25 cycles as the cells degrades in just a few cycles lol.


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## zebraa (Apr 17, 2014)

chop_tomatoe said:


> First of all statement:
> I am aware of fire/explosion risk and i'm not recommending anyone to try to recharge non rechargeable batteries.
> [...]
> But i wanna try this.



Take your own advice, don't do this.

Eneloops are the way to go.


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## TinderBox (UK) (Apr 17, 2014)

I have had a few charger`s years ago that could charge disposable battery`s , the best battery`s to charge are ones that have been drained quickly say in a digital camera, or flash gun or flash light or similar, they charge the best you can get 5 charges or more, battery from clocks or remote controls don't charge, or charge very little.

But in my opinion it is a waste of time, with leakage and risk of explosion, 20+ years ago when i was recharging alkaline battery`s ni-cd were 500mah , now we have 2900mah ni-mh charging alkaline battery`s time has come and gone.

Buy some Eneloops and a good smart charger

John.


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## Ford7.3PSD (Apr 18, 2014)

TinderBox (UK) said:


> I have had a few charger`s years ago that could charge disposable battery`s , the best battery`s to charge are ones that have been drained quickly say in a digital camera, or flash gun or flash light or similar, they charge the best you can get 5 charges or more, battery from clocks or remote controls don't charge, or charge very little.
> 
> But in my opinion it is a waste of time, with leakage and risk of explosion, 20+ years ago when i was recharging alkaline battery`s ni-cd were 500mah , now we have 2900mah ni-mh charging alkaline battery`s time has come and gone.
> 
> ...



It is generally not worth it to try recharge non rechargeable batteries. I have tried to do it with some make shift battery charger and a 270mAH charger. In my experience even if they don't leak while recharging, they will leak later on a few months later. 

I have never tried out Eneloop but I have 18 Duracell rechargeable AAA "Stay Charged" 800mAh batteries. These are low self discharge and I use them in my LED flashlight. I have only charged them a few times since I bought them.

Does anyone know what is the best for rechargeable C,D & 9v batteries? I don't like those D batteries with 2500 mAh capacity. I am looking for some in the range of 5000-10,000 mAh.


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## Ardillakilla (Apr 20, 2014)

I have Tenergy Centura C & D cells and have been happy with them.


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## yellow (Apr 21, 2014)

Ford7.3PSD said:


> Does anyone know what is the best for rechargeable C,D & 9v batteries?


an *18650 Li-Ion*


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## Conte (Apr 27, 2014)

I've done it before using a manual method.

Have a 1a variable voltage power supply I built using when I was a kid. Still works. 
I run an ammeter in series to the battery to carefully regulate the charge rate. 
Can't remember the settings. Like other I did it just to try.

One persuasion was to preserve "collectable" batteries. 
One that note, I should check them to see if they kept their charge. 



Ford7.3PSD said:


> Does anyone know what is the best for rechargeable C,D & 9v batteries? I don't like those D batteries with 2500 mAh capacity. I am looking for some in the range of 5000-10,000 mAh.




I've had good luck with this brandof D cell:
http://www.onlybatteries.com/showitem.asp?ItemID=18194.61&cat1=14&uid=1416

They will self discharge tho'. I've treated mine right, babied them even and they still work well after years. 
That company I buy from has some 10ah Low Self discharge versions now called "Acculoop". I wonder if they are any good. That supplier is Canadian btw. I'm in Canada.


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