Random battery charge question

[Hallis]

I got some random NiMH cells a while back, AA's. C'd and D's, The only printing on them is

G.I. Ni-MH
Rechargeable
Size D 8000mAH
Made In China

I tried googleing but didnt get anything. Do you guys think it would be safe to charge these at 2A not knowing how old they are?

Or should I just attempt at 2a and keep an eye on the heat?

Shane

 

[Jay R]

I'd suggest 1 amp, keep an eye on them and if they don't seem to get very warm, try them at 2 the next time.

 

[winny]

Most NiMHs theise days can take 0.5 C without problems but since generic made in China batteries are perhaps not the best and reliable in the world, Jay R's idea to start with 1 ampere seems like a good idea.

Please post your findings.

 

[SilverFox]

Hello Hallis,

It depends on what you are planning to use them in...

It is OK to charge them at 1 amp, but the termination signal may be missed. Keep an eye on them for heat. When they start to warm up, take them off the charger.

C and D cells are not as sophisticated as AA cells and have higher internal resistance. I have some 8000 mAh D cells that can not be charged at 0.5C. They melt at that rate. They do well at 2 amps and warm up at the end of the charge and give a good end of charge signal. The only time they miss termination is when charging on my old Vanson Speedy Box at 0.7 amps. They seem to properly terminate about half of the time. The rest of the time, the charger times out. This tells me that 0.7 amps is too low a charge rate for them.

If they were my cells, I would charge them at 2 amps. If I found that they couldn't take it, I would recycle them.

Tom

 

[Hallis]

I'm going to be using them in a flourescant lantern. 4 of them. I'll try them at 2A and see how they hold up. IF they dont get hot i'll back them down to 1A. Have to wait till my Indi 16x4 Pro charger gets here.

Shane