I suppose this is the most appropriate place to ask about batteries...

I am talking about your standard home or discman-use batteries (A,AA, AAA etc.) Many of my AA batteries are in the need of being replaced. I have noticed that Nickel Metal-Hydryde (NiMH) are slowly replacing NiCD batteries. What is the difference between a NiMH and NiCD battery (besides the chemical element)? Do the NiMH suffer from the memory effect as well? Is there a higher ampere capacity? Besides, can anyone explain me why the standard rechargable batteries (AA, AAA) always come in 1.2V instead of 1.5V? :confused:

My kids had loads of Walkman's, gadgets, Psions, torches etc and I seemed to be always buying AA batteries. Six months ago I bought 4 AA NiMH 1800mAh batteries with a charger and an extra set of 4 batteries, problem solved. Now theres always a set of batteries available when we need them and they are as good as and last as long as the Duracells I used to buy. I reckon I recovered the cost after about three months. As they are NiMH they don't suffer from memory loss, once charged they stay charged whereas NiCad lose some of the charge even if you don't use them.
You can get them here with free UK delivery, I bought them locally but I bought a laptop battery here..
http://www.gmkbatteries.co.uk/acatalog/GMK_Batteries_co_uk__NiMH_Rechargeable_batteries_97.html

Found this on thier site..

NiCad - Nickel Cadmium, older type of rechargeable battery.

NiMH - Nickel Metal Hydride, a newer type of rechargeable battery. Offers higher capacities and improved performance over NiCad.

Lithium-Ion - The newest type of rechargeable battery. Lighter in weight and can offer higher capacities over NiMH

Alkaline - Disposable, environmentally friendly, non-rechargeable, 5 year shelf life.

Lithium - Non-rechargeable, high energy density, 10 year shelf life.

Dry Lead Acid - Valve regulated lead acid batteries, sealed for life - non-spillable and Maintenance free. Common applications include, Alarm Systems, UPS systems & Medical equipment.

Don't know why theyre 1.25v instead of 1.5V

The voltage difference is because the chemical reaction for each type of cell is different, resulting in a different voltage. Each individual cell then gets connected in series &/or parallel to make up the required voltage & capacity however the physical size of the packaging imposes limits on just how many cells can be used.


NiMH do have a memory effect, but it's not as bad as NiCad, There are also limits to the number of recharges the different types have.