Batteries and charge

[Photofarmer]

Had chance of storms here yesterday, never happened.

But checked spare "fully charged" batteries yesterday morning one took charge for about 5 minutes the other 15 minutes do they leak power.

Just sitting in a pocket in camera bag since mid november.

 

[Tim Mayo]

Most lithium-ion batteries will self-discharge overtime and this can vary depending on temperature / humidity etc. I wouldn't be too concerned unless you are losing like 50% of the charge in only a matter of days.

 

[Bryan Conner]

I agree with Timothy, no worries unless the discharge is really significant. From what I understand, and remember, Lithium-ion rechargeable batteries, when stored at optimal temps (@20°c/68f) can have a self-discharge rate of 0.5-3% per month. If the storage temperature is lower than this, the discharge rate can increase, a lot if the temps are really low.

As far as the fact that one battery charged longer than the other, that doesn't necessarily mean that one had discharged more than the other. Lithium-ion chargers have a lot of technology in them and it may take the charger longer to be satisfied that one battery is indeed fully charged when compared to how long it needed with the other battery. If you are interested in how this works, Battery University has a lot of good info on this. Battery University Lithium Ion charging