Canon 7D battery life and "Cannot communicate with battery" error?

My 7D about 4 months ago (I haven't used in a few months due to Army stuff) started giving me the "Cannot communicate with battery" (CCWB) error. I'm just learning to live with it at this point, but I've realized that ever since that error has started, it's had a much shorter battery life than it did before. There were times where I'd accidentally leave the camera on for a day or two, and the battery would still be at 100%, or at least 75%, and I could shoot with it all day. Now it just dies a lot more quickly when left on, and lasts probably about 500 shots or less.

Anyone experience anything similar? Any solutions perhaps?

Is this happening with multiple batteries, or just the one?

Is it a Canon battery or aftermarket?

I only have one battery. :S It's the Canon battery. I can't exactly afford a new one right now.

quadwing wrote in post #16965103
There were times where I'd accidentally leave the camera on for a day or two, and the battery would still be at 100%, or at least 75%, and I could shoot with it all day. Now it just dies a lot more quickly when left on, and lasts probably about 500 shots or less.

Keep in mind that most Canon cameras go into a "sleep" mode when left on so this maynot be an indicator. Beyond the advice/questions already presented, how is the behavior of the battery/charger combination? Are you getting proper indication of a full charge? Do you have the ability to measure the voltage across the battery terminals?

quadwing wrote in post #16965266
I only have one battery. :S It's the Canon battery. I can't exactly afford a new one right now.

Look on amazon at the wasabi brand aftermarket batteries. You can get one for around $10. They work fine. It's most likely a battery failure rather than a camera failing so I would start there.

quadwing wrote in post #16965266
I only have one battery. :S It's the Canon battery. I can't exactly afford a new one right now.

gonzogolf wrote in post #16965282
Look on amazon at the wasabi brand aftermarket batteries. You can get one for around $10. They work fine. It's most likely a battery failure rather than a camera failing so I would start there.

Or the SterlingTek at http://www.amazon.com …on+7d+sterlingt​ek+battery.

How old is the battery and what does the camera show in the menu as to the batteries condition?

When batteries sit for a few month they often develop a chemical film on the contacts. I'd clean them first and see if that helps. I use contact cleaner on a q-tip for both camera terminal and battery. Don't spray on gear directly! Even a good wipe with a clean cotton cloth can remove most of it. Fixed my camera a few when it lived in the bag for the winter waiting for good light...

There is a known issue with screws working loose on the 7D PC board, causing rapid battery drain. I'd check all the obvious stuff--clean contacts, reset camera, try new battery--before performing this surgery:

http://www.dpreview.co​m …age=3#forum-post-51929450

I had this happen. It is most likely due to a broken PCB which mates to the battery, inside the camera. I tried everything I read about before finally having Canon repair it. I think that cost something like $245, but it brought my baby back to life. Good luck OP!

I just sent mine to Canon for a similar issue. If it's happening with multiple batteries, you'll probably need to send it in.

If you qualify for CPS Gold, for $100, you get 20% off and free return shipping. My total was $175.20, saving $66.80. The CPS strap you get for joining seems to sell here for $50 if you don't want it. It worked out for me because I had more than one item to go in for repair.

Sorry, I've been away the past couple of days. Once I can get in front of my camera (it's across the country right now >_< I'll try some of those things out and update you guys. But I think it's the camera. I haven't tried another battery though. We'll see I guess.

But yeah, rapid battery drain even in "sleep mode" is the issue.

Also, this is my 666th post. Just throwing that out there. Dun dun dun.

quadwing wrote in post #16971289
Also, this is my 666th post. Just throwing that out there. Dun dun dun.

You devil you.

quadwing wrote in post #16971289
Sorry, I've been away the past couple of days. Once I can get in front of my camera (it's across the country right now >_< I'll try some of those things out and update you guys. But I think it's the camera. I haven't tried another battery though. We'll see I guess.

But yeah, rapid battery drain even in "sleep mode" is the issue.

Also, this is my 666th post. Just throwing that out there. Dun dun dun.

I had that for about 8/9 months. It was on the original Canon battery I had. My Canon battery was dying in hours from a full charge. I bought an after market battery, ( it cost about half what the Canon version ) the error code continued, I had no battery level indicator in the viewfinder either.

I kept meaning to do something about it, just never got around to actually doing it. Then, all of a sudden, everything came back to life and its been fine ever since ( about a year now ). It holds it charge, the battery level indicator works now with the new battery.

A theory of mine is, the original Canon battery dies and somehow, does some damage to the cameras electronics. From what I've read on these posts the common denominator in these threads is the dying of the battery. Perhaps that's why it rights itself in so many cases after a prolonged period...............

Anyway, good luck with yours, I hope it sorts itself out.

quadwing wrote in post #16971289
Also, this is my 666th post. Just throwing that out there. Dun dun dun.

Meh, post one more and you're no longer the sign of the beast How long have you been using this battery? As was previously stated, check your battery health in the menu. From what I've read, Canon and others recommend just replacing the battery by the time it's two health bars. At least these lithium ion batteries seem more consistent: they hold their charge a lot longer, and their lifespan seems to be equal to usage. Then again, if your camera is constantly giving you cannot communicate errors, there could be improper seating with contacts (be it dirt/film/etc). I could also see that improper seating would continually cycle the battery. Perhaps first cleaning all contacts, then checking the battery health is in order. If the battery health still is low, I'd recommend going with a Canon battery. 3rd party batteries are hit or miss as to how long they'll last.