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Canon 7D Error - Cannot Communicate with battery. Use this battery? Press ok.

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David Turner
Canon 7D Error - Cannot Communicate with battery. Use this battery? Press ok.
on Jul 22, 2012 at 7:38:13 pm

Hi All,

My Canon 7D has out of the blue started getting the error: "Cannot communicate with battery. Use this battery" when I turn it on.

If I press OK, I can use the battery, but it will not show me battery life, which for me, is extremely important in the field.

There were no changes or damage that caused this. In fact, I was just shooting in my apartment over 2 weeks. It worked fine one day, went back in the case, then had the error the next day out of nowhere.

- This is definitely a camera issue as I have exhausted all battery issue scenarios. All my batteries work fine in my Canon 5D Mark iii. And the new battery that came with the 5d Mark iii does not work in the 7D.
- The camera is no longer in warranty, it is 19 months old. I consider this pretty new and should not be having these problems.
- There are other posts online that mention a crazy fix of putting the camera in the freezer then taking it out and putting the battery in. I don't see how this would actually fix anything and I'd rather not do it.

- Has anyone fixed this problem themselves? And if so, how have they done it?
- Has anyone convinced Canon to fix this free of charge even though warranty is out of date?
- Has anyone had this problem on a 5D? I'm worries about this happening to my new camera once the warranty is out.

Thanks for your help!

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bill sumner
Re: Canon 7D Error - Cannot Communicate with battery. Use this battery? Press ok.
on Aug 18, 2012 at 3:02:08 am

i have the same issue with a 5d mark 3 which i'm sending in for repair

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Ervin Tia
Re: Canon 7D Error - Cannot Communicate with battery. Use this battery? Press ok.
on Aug 29, 2013 at 7:18:51 am


Any update on this issue?
I just got got this error after 3 years of normal operation.

Ervz | Video Productions | WMC-AP, Philippines

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James Holtzman
Re: Canon 7D Error - Cannot Communicate with battery. Use this battery? Press ok.
on Oct 20, 2014 at 2:17:11 am

7D owners (and others), I hope this fixes your problem, don't waste your time resetting the camera, wiping battery contacts, putting it in the freezer, etc.

I didn't mention in posts on other forums, I've been an instrument technician for more than 40 years and don't have a problem going into the camera and making the repairs, I've done so on other Canon cameras and Canon lenses. Service manuals don't always give the order of which screws need to be removed. I wouldn't know in the case of the 7D because I've never seen a service manual.

We have been led to believe that the cause of the problem was due to a screw making the ground connection on one of the circuit boards had come loose and was floating around inside the camera. The first symptom is that we get the famous error as described on the subject of this thread. If the problem goes long enough unfixed, not only can we not read the battery level, I've heard that even if the camera is
turned off, the battery will discharge over a very short period of time. Worse than that, if the loose screw shorts between some traces on any of the boards, catastrophic results will occur, then circuit boards actually will have to be replaced.

I held off repairing my camera, simply because I didn't have the time.

I put out the request on multiple forums asking which screws need to be removed. As it turns out, a total of eight screws need to be removed to remove the bottom panel of the camera. Six screws on the bottom and one screw on each side of the camera. I took my camera apart, found the loose screw, applied a tiny drop of #242 blue loctite and put the screw back where it belonged. It should have been loctited in the
first place, never was, I have heard that Canon is charging people as much as $300 for a repair that never should have been necessary, because of a factory defect. I took a photo showing the bottom removed, it is obvious as to where the screw is missing from. The screw was jammed up into the camera, a couple taps on a table top loosened the screw. There are three types of screws, three of the screws on the bottom have a blue thread lock, probably loctite. Three of the screws on the bottom do not, they are the same size. The two screws on the left and right side near the bottom of the camera are a little longer than the bottom screws, don't get them mixed up.

I would attach my photo showing where the screw is missing from but don't know how to attach a photo to this post. I've seen similar photos elsewhere on the web.

We owe the help to John Clark
Pelagic Visions Marine Imaging
Blue H2O Cozumel Watersports

USA Direct 813 398 0791
Mexico Cell 987 111 2170
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John made a 15 minute video, it is on youtube showing exactly what he had to do to perform the repair.

This video is being shared with John's permission:


As I mentioned, if you let this problem go too long, it may only get worse, damaging more boards and costing you more money.

And, yes, I did ask others which screws were to be removed, I didn't have the time to experiment, I had other priorities.

Jim, owner of many Canon products

Empirical Technology

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