Is this normal?

I'm using eneloops AA's and am getting a nice dimple in the NEG side of the batteries. I had a pair I used forever and they almost had a crater.

I was wondering if this is normal for NiMH, or if me charging them in a 15 minute duracell charger is whats causing the deformation; I was thinking perhaps eneloops were meant to be charged on a slower charger and not a rapid one.

Another thing, I've been only using them in my Fenix LD20.

Appreciate any comments.

:thinking:


http://i918.photobucket.com/albums/ad26/jessicaparker5353/100_2136.jpg

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It appears that your light was dropped with enough force that the positive battery contact in the head acted pretty much as a wall. There is no spring in the postive contact on the head to absorb the energy of the shock during a drop. This shock energy has to go somewhere... The cells will still work though.

FYI I don't recommend using those "quick chargers" as they reduce the lifespan of your cells by basically cooking them.

LilKevin715 said:

It appears that your light was dropped with enough force that the positive battery contact in the head acted pretty much as a wall. There is no spring in the postive contact on the head to absorb the energy of the shock during a drop. This shock energy has to go somewhere... The cells will still work though.

FYI I don't recommend using those "quick chargers" as they reduce the lifespan of your cells by basically cooking them.

Click to expand...

I didn't think of dropping my light as being the cause. My old L2D (just sold to novice) was beat to hell from being dropped, and it had the batteries with the craters lol. I will keep this in mind; its just at work I use my light so much its near impossible not to drop it here and there.

I have an accu manager 20 I bought, but never used much. I should use the accu when I start using the eneloop xx's I got in the mail today. The accu says "super fast charger" on it, but I don't think its anything like the 15 minute charger I've been using.

spydie fanatic said:

I have an accu manager 20 I bought, but never used much. I should use the accu when I start using the eneloop xx's I got in the mail today. The accu says "super fast charger" on it, but I don't think its anything like the 15 minute charger I've been using.

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Check the mA rating, anywhere above 1000mA could damage your Eneloops; anywhere above 500mA may damage older/cheaper cells (recommended charging rate is usually indicated on the cell).
It's also very important the charger terminates when the cell is done charging.
I'd be very distrustful of a 15-minute charger, since even if it didn't come with specialty cells, it's unlikely the amperage will be healthy to regular NiMHs.

spydie fanatic said:

I didn't think of dropping my light as being the cause. My old L2D (just sold to novice) was beat to hell from being dropped, and it had the batteries with the craters lol. I will keep this in mind; its just at work I use my light so much its near impossible not to drop it here and there.

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This type of damage is also commonly caused by very rigid springs (in either flashlight or charger), but I wouldn't worry about it too much on NiMH cells. It's much more dangerous to encounter this on Li-ion cells.

Thanks for the replies guys. I found the manual to the accu manager 20; its 700mA on AA.

700mA is pretty good rate if it does proper delta-V termination. Check the manual for that (delta-V termination might also be called "microprocessor-controlled end of charge detection" or something like that)

I've had that happen on cells in the past, and have never had a problem. Heck, I've got some Tenergy RCR123's in which one cell is dented on the negative side. This is due to the fact you're pressing the hard nipple of the positive anode against it. This doesn't happen when it's something soft, like a spring (or at least it's nowhere near as extensive).

Here's a pic of my batteries.

http://i3.photobucket.com/albums/y85/Bstrickler/all from phone/IMAG0341.jpg
http://i3.photobucket.com/albums/y85/Bstrickler/all from phone/IMAG0342.jpg

As you can tell, the first battery is the one that's always at the front (I'm OCD like that)