anyone clued up on AA batteries?!

[vw_golf_nutter]

Sorry, this may seem like a really stupid question but ive had a bit of a burning accident with a childs toy tonight and i hope it wasnt my fault.
I have a whole load of different rechargable batteries, they are all 1.2v but some say 2000mAh and some are 1300mAh. I have used them together before but is that ok? I mean they wouldnt react badly used together would they? I have no idea what the mAh thing is.
Also this toy says to use with 1.5v Alkaline AA batteries. Obviously ive been using the wrong batteries as ive been using 1.2v rechargables, but again would this cause a bad reaction?
thanks!

[DubFan]

mAh is milli-amp hours. IE it tells you how long a battery lasts.
So a 2000mAh will give you 1milli-amp of power for 2000 hours. But most toys will need say 100-250milliamps of power so a 100mA toy will drain a 2000mAh battery in 20 hours.

If you mix a 2000mAh battery with a 1300mAh battery, the toy will just run until the lesser battery is drained and the better battery will still have some power in it, but not enough to run the toy. It should be ok, and I wouldn't have thought it could cause something to overheat in the toy unless there is a fault in the toy.
You are more likely to have a problem if you mix them while recharging. If you charge a 1300mAh battery with a 2000mAh battery at the same time, the 1300mAh battery will be fully charged sooner but because the 2000mAh battery isn't the unit will continue to charge the 1300mAh battery even though it is fully charged, which could cause the battery to get hot.

http://www.component-shop.co.uk/html/batteries_explained.html

[Thom89]

Basic rule of thumb... Don't mix battery types, outputs, or makes. Match the ones that you have, and discard immediately anything that looks not healthy or you know to be old, I discard rechargeable's after about 4 or 5 years regardless
Never leave batteries in any items that are prolonged out of use, they will eventually leak and damage the insides
I also only buy decent branded batteries, but nearly always end up with rechargeable "Uniross" they seem to be the best all rounders, and reasonable price...

Thom