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Thread ID: 88593 2008-04-01 22:29:00 NiMH Battery Charger B.M. (505) PC World Chat
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655086 2008-04-01 22:29:00 Yesterday I purchased a NiMH AA-AAA battery charger from Dick Smith. (M9562)

I placed 4 new 2000mAh AA batteries in it and left them to charge.

3 hours later the LCD was displaying that all four batteries were about ¾ charged and still charging.

Fine, except the batteries were almost too hot to handle. I let them cool and placed 2 in my DigiCam and they seem to work fine.

So my question is: Do these batteries always get very hot when charging?

The Manual claims one of the features of the charger is that it has protection against Over Charge – Polarity Reversal – Over Heating – Over Voltage – Over Current and Short Circuits.

It is just the heat of the batteries that is bothering me.

Should I return the charger or is all the heat normal and not destructive? :confused: 		B.M. (505)
655087 2008-04-01 22:40:00 The batteries will normally become reasonably hot when charging, particularly in a rapid charger. As long as they're not too hot to touch, they're probably just fine.

Just out of curiosity, why on earth did you buy 2000mAh batteries? You can get 2500mAh Energizer ones for the same price... 		Erayd (23)
655088 2008-04-01 22:47:00 It is a Fast Charger, you trade charging speed against ultimate battery life.

There is something wrong however as the charger should have fully charged your 2000mAh batteries in 2 hours so 3 hours at a fast charge is too long and would explain why they were so hot. Maybe why DSE are discontinuing this model :) 		PaulD (232)
655089 2008-04-01 23:15:00 Just out of curiosity, why on earth did you buy 2000mAh batteries? You can get 2500mAh Energizer ones for the same price...

I didn't know. :o

And yes Paul, you may well be right? It's got 12 month warranty so if it stuffs the batteries I'll be back looking for a new charger and batteries. :D 		B.M. (505)
655090 2008-04-02 04:50:00 G-F suggested that DS batteries were good,so I bought 8 for my camera and a DSE charger,they last about 5 mins in camera as apposed to Energiser batteries I bought off DSE as they were out of stock of there own.
So thats the last of trickies batteries I will be buying. 		Cicero (40)
655091 2008-04-02 07:04:00 Yes, they do get hot. beeswax34 (63)
655092 2008-04-02 07:47:00 Yesterday I purchased a NiMH AA-AAA battery charger from Dick Smith. (M9562)

I placed 4 new 2000mAh AA batteries in it and left them to charge.

3 hours later the LCD was displaying that all four batteries were about ¾ charged and still charging.

Fine, except the batteries were almost too hot to handle. I let them cool and placed 2 in my DigiCam and they seem to work fine.

So my question is: Do these batteries always get very hot when charging?

The Manual claims one of the features of the charger is that it has protection against Over Charge – Polarity Reversal – Over Heating – Over Voltage – Over Current and Short Circuits.

It is just the heat of the batteries that is bothering me.

Should I return the charger or is all the heat normal and not destructive? :confused:


Looks cheap and nasty to me. I don't like the DSE branded stuff. I have a 15 minute NIMH charger (VARTA brand), but it came with special fast charge batteries. It will aslo charge normal NiMH batteries in an hour, but I don't think the charge lasts as long. It also has a fan in the side that cools the batteries as they charge, and the 15 minute charged batteries do get hot. I also have a normal NiMH charger that takes about 12 hours, and normal NiMH batteries charging in it don't get very hot, just warm. 		robbyp (2751)
655093 2008-04-02 08:01:00 Thanks guys, most helpful . :thumbs:

I’ve taken aboard your comments so we’ll se what happens . ;)

So far so good, batteries seem to be fine, but any other battery I’ve had anything to do with, including Lead-Acid, didn’t like that much heat .

What’s got me is these AA’s are rated at 2000mah . Are they telling me they will carry 2 amps for an hour? :confused:

Tell you now, I don’t believe them . :rolleyes: 		B.M. (505)
655094 2008-04-02 09:13:00 Heat is damage.

If your haappy to cook em while charging, then its not a problem...Unless they explode but lets hope the cut off kicks in before that happens. 		Metla (12)
655095 2008-04-02 11:53:00 Thanks . . .

What’s got me is these AA’s are rated at 2000mah . Are they telling me they will carry 2 amps for an hour? :confused:

Tell you now, I don’t believe them . :rolleyes:
The low grade ones definitely won't and the good ones won't exactly either . Most batteries (including lead acid car batteries) are rated at a ten hour rate eg . 8 Amp for 10 Hr = 80 AH Taking 80 Amps out you would get way under an hour's supply .
Some batteries are built to dump their charge quickly, others are going to spit the dummy at high rates .
Your batteries should supply (when having had the optimum number of charge / discharge cycles since new, and freshly charged) 200 mA for 10 hours if they have been kindly treated . Ni-MH cells will only reach their optimum performance after a few cycles, but it seems important to ensure the initial charge should be at about the 10 hour rate (0 . 2A in your case) maintained for 16 hours or so . If this is not observed the life and performance of the cell(s) will not reach it's full potential (sorry) .
Fast charging is convenient, but takes a toll on the lifetime of the cells . Heat is not great for life prolonging on any Ni-MH cells, but some of the high performance cells can withstand a surprisingly severe environment . As usual, the cheapest cells will not be the best performers, but the most expensive ones will not necessarily be tops either . 		R2x1 (4628)
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