Battery maintenance: How many days can I leave a spare battery uncharged ?

[stan10]

Hi guys
I have about 2 spare batteries and I would like to know how many weeks / days I can leave a battery uncharged without damaging it.
I hope to get some response. Thanks in advance

 

[thx1138v2]

Battery charging and discharging profiles differ depending on the battery chemistry.

Many of the old NiCad batteries benefited from fully draining them and recharging them.

Lithium Ion, on the other hand, is the opposite. They need to be kept fully charged as long as possible to extend their life. So if you are talking about phone or laptop batteries, you need to fully charge them before removing them. Otherwise, they may not take a charge later.

By the same token, you should use your device while connected to the charger when possible. For instance, when you are at home keep your laptop on the charger while you are using it and only use the battery when no outlet is available.

How long they will hold that charge depends on their charge when stored and the environment in which they are stored.

 

[stan10]

thanks for your reply, in my case I would be away for about a week , maybe 2 . so I would like to know if Li-Ion laptop batteries can stay uncharged for 2 weeks without damaging

 

[thx1138v2]

thanks for your reply, in my case I would be away for about a week , maybe 2 . so I would like to know if Li-Ion laptop batteries can stay uncharged for 2 weeks without damaging

Probably not. They may not be damaged per se but they probably won't take a full charge thereafter.

As I mentioned earlier, Li-Ion batteries need to stay as near their full charge as possible to maintain their lifespan.

You might consider getting a simple solar panel charger for them if you're not going to have access to an electrical grid.

 

[Onus]

Your batteries will be fine if left alone for a couple of weeks.
As thx1138v2 says, battery chemistries differ, but I think he may be mistaken on some aspects of Lithium-ion batteries. My Lenovo will not charge its internal battery unless it has dropped below 95%; constant charging is not good for them.
Most batteries (other than NiCd cells) should be kept at 60% state-of-charge or higher (lead-acid should be kept as high as possible without overcharging). Li-Ion has a self-discharge rate low enough that they can sit for a few months and not drop that low.