[Nospam]

Just had an interesting email exchange with Thomas Distributing.

2 of my 3 Maha 9V batteries went bad a few months ago (less than 2 years after purchase). They've each been recharged less than 25 times, alway using the Maha charger.

According to TD, these batteries (thus, I assume all NiMH batteries) need to be recharged every 30 days, whether they're used or not. Sounds bogus to me... what about all the batteries that sit on shelves for months before being sold? So, has anyone heard this claim before?

In any case, they're giving me a 10% discount on my next order, and I wanted to get some of the 230mAH 9V (and some more AAA) anyway, so it's not all bad.

 

[Jon L]

NiMH batteries can be brought back to life! Put them in a ziplock bag and place in the freezer for a couple of days. Take them out and fully recharge them, and they should be good for awhile. I did this several times with success on my home phone's "dead" NiMH batteries.

 

[Nospam]

Thanks for reminding me of that trick! Someone told me about it a few years ago, but I completely forgot about it.

I'll give it a shot, although I'm still planning to order some more batteries to take advantage of the discount

 

[SiBurning]

Consult The Battery FAQ
From the FAQ...
NiMH requires maintenance every 60-90 days. Thomas is just being conservative.
NIMH details
I don't see lifetime in there (with just a quick look) but I seem to remember it's about two years.

You really want to buy batteries fresh. I suspect this is a factor in the problems that plague iPowerUSA. The cells inside their 9V batteries are full of crud, possibly suggesting long sitting times in an unfriendly environment.

To bring them back to life, if it works at all, will take several charge cycles to get them back in reasonable shape. I don't know whether or not the freezer helps in resuscitating depleted NiMh batteries, but the claims about putting batteries in a freezer to extend their life turns out to be incorrect. The correct procedure there is to seal airtight and put them in the refrigerator--low temperature helps, freezing can damage a battery. Now this situation might be completely different, since you're purposely trying to shock it, but I'd be careful about any advice to put anything in the freezer.

While I'm on the soap box... I find 9V batteries are hard to maintain because it's several cells in series. If one goes bad, and they easily do when put under the loads our audio equipment requires, the whole package becomes useless. Since there's no way to remove the single cell and condition it spearately, the whole thing usually ends up in the trash. Not that you can't get good use out of them, but even good batteries can occassionally go bad quickly because of this.