Charging spare batteries?

[Drachirryz]

I have a Canon EOS Rebel T5. I recently purchased a couple of spare batteries. Is it a good idea to charge the batteries far in advance of being used? How long does a charged battery last if it isn't in the camera?

[ebiggs1]

I feel it is best to keep batteries fully charged.

[Drachirryz]

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@ebiggs1 wrote:

I feel it is best to keep batteries fully charged.

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Thank you.

[ebiggs1]

Nickel-based batteries can be stored in a fully discharged state with no side effect.   Li-ion cannot dip below 2V/cell for any length of time. Copper shunts form inside the cells can lead to a partial electrical short. When recharged, the cells might become unstable, causing excessive heat or exhibit other issues.

But you do as you see fit.

[theandies · Accepted solution]

    If batteries will be left unused for 3 months or more, partially recharge them (to around 30-70% of capacity, depending on planned storage time), then store the device to prevent battery damage (cover the contacts and store at room temprature.  Remember never touch or short the contacts at any time).  If the contact need to be cleaned I usually use a pencil eraser but most modern contacts are gold plated and don't need cleaning. You may need to take the device out of storage and charge again after a few months.  If you know you're going to use them a lot I suggest charging fully though. 

     With my T6i I have not ran out of battery yet while in the field so I've not needed an extra battery.  The longest in the field was a two day trip to Zion National Park in Utah and I still had battery left.  I don't use live view much and have not shot much video since I bought my camera a couple of months ago so I've really not put the battery through it's paces yet. Using the LCD will naturally drain the battery faster. The good thing about Lithion Ion batteries is you can "top them off" to 100% no matter where the charge level is the night before you go out.  This gives you piece of mind knowing you are stepping out the door with a full battery (of course if you have an extra you don't have to worry as much).