Alkaline vs NiMH batteries

[Altec]

Noticed that alkaline batteries are 1.5V while NiMH batteries are 1.2V. Does that mean that NiMH batteries give poorer performance e.g. less powerful flashes?

Any idea how many mAh does a typical alkaline battery have?

 

[ckiang]

Originally posted by Altec
Noticed that alkaline batteries are 1.5V while NiMH batteries are 1.2V. Does that mean that NiMH batteries give poorer performance e.g. less powerful flashes?

Any idea how many mAh does a typical alkaline battery have?

No. Alkalines might have a higher voltage, but internal resistance is higher than NiMHs and they cannot sustain supplying a large current for long. So, in digital cameras, they typically die after 10 minutes or so of usage.

NiMHs can provide high current to the appliance being powered for a period of time, afterwhich they die pretty quickly and needs to be recharged.

Regards
CK

 

[tangcy]

Are there Li-Ion recharable AA batt ?

 

[ckiang]

Originally posted by tangcy
Are there Li-Ion recharable AA batt ?

Not that I know of. And the non-rechargeables are damned expensive.

Regards
CK

 

[mpenza]

Alkaline have ~3500mAH. But they do last as long in digital cameras as they are not well suited for high current drain usage.

 

[YSLee]

Another point to note that alkaline's 1.5v is applicable only when the battery is darn fresh. After some time, the voltage level will drop, sometimes below 1.1v even!

NiMH on the other hand, has different voltage drop off characteristics. Generally it is 1.2v throughout, until when it finally dies, then there'll be a very sharp drop off after that.