Storage and life of batteries

[AlanF]

This must have been discussed in the past, but it is so general and there are always new members so it is worth raising. I gather from the internet that Li ion batteries are best stored at about 40% charge, where they degrade about 3x more slowly than fully charged, and should not be allowed to drain. It's not very convenient to have half-charged batteries when you have to grab extra ones for a shoot. So do people actually store them half-charged?

What prompted this is that I just checked the LP-E6 left half charged and very rarely used in my 7D. It read in the menu 46% charged but the previous two green bars for Recharge Performance had dropped to a single red.

So, is it bad practice to leave the battery in a camera for long periods unused? Does the red bar mean that it is now shot (I'll find out later myself this weekend)?

 

[friedkimchi]

I've stored my original Canon batteries for my 50D inside the battery grip for more than 3 months and when I switched it on, the battery meter was still full.

It was fully charged before leaving it inside the battery grip.

Additional details, I don't store my camera in a dry box or anything. It just stays in my camera bag while not in use. Camera bag contains silica gel.

 

[alexanderferdinand]

I try to keep mine between 40 and 80% charge.
This is said to be the comfort zone for LiIon- cells.
And if I expect a journey or a longer session I charge them full.

A red bar means the battery is loosing capacity. I have one, still working with appr. 20% less actuations possible.
A user recently wrote, a cell with red bar heated up when charging.
Didn't notice that, but with LiIon I would always be cautious. Means, I am in the house when I charge them.

 

[insanitybeard]

I can't answer your original question Alan, but I've always tried to store my LP-E6's from my 7D fully charged so that they are always good to go, they've both recently dropped to 1 red square recharge performance after 3-1/2 years use, not sure if that's good going or not! So far both are working ok, though not lasting as well as they once did, I'll get another one to be on the safe side!

 

[Ewinter]

These batteries typically have a usage life of 3-5 years approximately anyway, if you use them regularly

 

[RGF]

I leave the battery as they are at the end of a shoot. May sit for a week or a month or two. Never had major problems

 

[Old Sarge]

I have 4 LP6 batteries, usually two in my grip and two in my bag (sometimes I take the grip off so it drops to one in camera and three in bag). One came with the camera and one purchased the same day (October 2009) and the other two purchased within weeks of that day. All now show single red box in battery check. But all seem to function well and I have not noticed any major decrease in the number of shutter functions per battery though it could be as high as 25% without me noticing. Perhaps there has been a decrease in storage life. I seem to notice that though it is purely anecdotal.

 

[andyhad]

Hi,

Have been lurking for a few weeks, and joined specifically to ask about battery life. I'm an enthusiast, graduated from EOS 1000 to 60 last year, and have just inherited my Dad's 5Dii. It has seen under 5k actuations, and he got it as a retirement present 2.5 years ago (upgrading from a 20D).

The batteries in my 60D typically lasted 700+ - I rarely had to worry about charge status. The first thing I did when I got the 5Dii last week was install magic lantern - have never used it before, but thought that a clean slate would be a better learning experience. Might have been wrong on that.

I noticed that his batteries seemed to be draining very quickly the last couple of days as I was getting used to it and setting things up. Took it out today and took one of mine out as a spare, as the first battery was at about 30% - after less than 150 shots total, I had to replace the first one and the second is now at 69%. This seems horrendous - even with plenty of chimping as I'm checking things out.

Is the 5Dii battery hunggry? Surely not...
Does Magic Lantern hoover up charge? Can't think why...
Is there some setting I've missed likely to have caused this? Possible, but it must be pretty power hungry...

Any input gratefully received!

Really loving FF + 24-105 btw.

Andy