[familia5az]

Typically how long can I expect a spare battery with a full charge to last before needing to recharge it ? A month?

Sent from my Galaxy Nexus using Android Central Forums

[zedorda]

Lithium-Ion batteries stored for 15+ days should be stored at 50% charge level and should be expected to lose 8%-31% per month based on storage temp.

For more info:

[mattmatt299]

I've kept a spare for my Android phones in the car since 2009 - sometimes for many months at a time and fully charged. I never noticed more than a few percent loss in charge. Keeping them at 50% charge may increase the life of the battery - but makes it 50% worthless as a spare. Given how cheap batteries are, I always keep a few fully charged ones around and spend the $10 or $20 a year for new batteries.