Overcurrent charging, did I probably damage these batteries?

nitebrite

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Jan 3, 2004
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I had some AA NIMH Powerx 1000MAH that were in the fridge for about 5 years. The went in the charger yesterday at about 31% charge. That is very good indeed. Then must have accidently set the charger to 2000MAH! I did not notice this until I smelled "faint" burning plastic. They were at 87C per laser thermometer. However the charger had not yet shut down on thermal protection which it most definitely has. I caught it when one was charged to 56% that had started at 29% and the one that started at 31% was now at 58%. Is it most likely that I damaged these batteries? They did not vent and seem to be fully intact. I have since discharged and recharged/analyzed them with no issue. Should I recycle these for sfety reasons or are they probably still okay to use since I caught it so early? I apologize for my recent stupid mistakes regarding these batteries. I never messed with NIMH. I only use LI-ION and LI-POLY. Thank you
 

MidnightDistortions

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Probably the only thing you did is reduce those batteries lifespan. NiMH batteries are pretty forgiving when it comes to abuse, at least for safety reasons. Those batteries are not in any danger, but did you burn the plastic on the charger or did the battery wrappers get damaged? Just curious because those were some toasty batteries.
 

nitebrite

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Jan 3, 2004
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No, amazingly nothing burnt at all. I am sure what I smelled was the wrappers but they did not even shrink! The charger is "fireproof" so no worries there. IMO, it is the best charger but there is no reason to get into that debate here. I am just glad for the good news. Since quality batteries are now hard to come by. It is all Chinese junk now. The last PowerX lasted in a phone mainly on 24/7 trickle charge for 11+ years! I would often talk 20+ hours on them! I made one mistake though, they are in fact AAA. I had said AA. I am just glad for this good news! In fact it probably did not even reduce it that much since it was right in the middle of the charge cycle? It uses different types of charges, you know like CV, CC ETC. So depending on what it was using at the time it may have not even reduced their life that bad if I am lucky. Seeing as the last ones lasted 11+ years in quite frankly abusive conditions. If these last 5 years I would be elated. After that it is probably down to the usual Energizer junk. Since the Eneloop Are just not worth the $20 in this situation. If I had any luck I might know where there might be some "Duraloops" still if these just happen to be no good for some reason. Mainly I just wanted to be sure they were not going to vent in my face and you confirmed that at least! Thank you very much!
 

MidnightDistortions

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Well there will be some reduced life. No way to tell until it happens. At least there was no damage, that you can see anyway. Duraloops are pretty good, haven't had any issues with Energizers either, the ones I got 2013's are still running great. Never seen a NiMH battery vent but had a few vent in my time but nothing spectacular. I can tell by the rust like stains by the vent holes (really old batteries).
 

nitebrite

Enlightened
Joined
Jan 3, 2004
Messages
629
There is someone here that reviewed the same charger with Eneloop AA's @ 3 Amps! He had the charger itself up to 92.2C and was not at all concerned I am not sure this is a good idea? I wanted to point out that they revised that charger in 2018 when I had purchased it. It now has 71.5MM sliders and accommodates 21700's just fine. It is one of the best "simple" chargers I have used. Although it does have quite complex microprocessor control.

https://www.candlepowerforums.com/vb/showthread.php?439468-Test-review-of-Charger-Folomov-A4
 
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