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Cannot communicate with battery - 7D


Dear Friends,

I am a proud owner of 7D for the past 2.5 yrs and have done many trips and shooting with that.

I am not using any battery grip. Have 2 Canon original battery with me.


Fromyesterday night I am getting an error  "Cannot communicate with battery". It is same described in the below link also :-


I am using Original Canon battery and I have tried with both of them but no result.

As per User Guide ,


If the message "Cannot communicate with battery" is displayed when checking the battery status, select [OK] and continue shooting. Please note that the battery level indicator will appear blank.


My concern is :-

1. If I ignore that and continue shooting , will it create any problem to the Camera functionality ?

2. Wil the battery drain fast due to that ?


I am Ok with not displaying the battery infor as of now ( which I will repair by Canon) but need to confirm that the battery functionality will remain as usual. I will be travelling for a birding trip soon and I due to short time I dont want to send it to repair...


Please guide.


Warm Regards,



I also have this problem.  I have multiple Canon and non-Canon batteries which all work in my 5Diii and get the "cannot communicate" problen on my 7D.


Although I was skeptical, I tried bud411's solution.  IT WORKED FOR ME!

Glad to hear this worked for someone else. Maybe it wasn't just a fluke (or the drop onto the tile floor). Would be interesting to hear others try this to see if it works.


After my camera started operating properly, I updated the firm ware to the latest version & all still working like it was designed to do.

updating my canon 7d firmware and installing magic lantern on it seemed to fix my 7d from draining the battery  and no longer does my 7d ask me if i should use the battery even though it cannot communicate to it, it still does not show power bar setting on the display, only in magic lantern does it show the level of power the battery has

What is this Magic Lantern you speak of?



Ok, so 2 1/2 weeks and $302 dollars later, I just picked up my 7D.  No errors, thankfully. Cleaned sensors - thank you.
90 day warrantee on this, so if the issue arrises again before March 7th- and I hope not - then it's covered.

However, can someone here from Canon translate this. - picture attached.

Very vague "Adjustments made to circuit board" What kind of adjustments, was it replaced, should I expect to have this "adjusted" again lets say a year from now? Did the batteries and / or updated firmware cause the board to go haywire? I take immaculate care of the camera so this was a totally out of the blue error when this started.

Is that the leading cause of this "battery communicate error?" After shelling out this kind of money, I thought I would get a more detailed explanation. Although I appreciate the fix, I see this error with MANY 7D cameras all over the web and other forums. Just Google "Cannot communicate with battery 7D" 

If this is a flaw, Canon needs to own up to this and issue a recall if these circuit boards are an issue. 

(Clean and adjust to factory specs - That I understand was sensor cleaning and a deep check to see if the camera is working perfect) 


Canon Repair Invoice - 12/7

Hate to beat a dead horse with this issue, I did have to drop close to ANOTHER $200 on two new EP-L6 batteries. I went to use the camera a few mornings ago - first time in 4 days on fully charged batteries, noticed the battery icon - using my battery grip with 2 L6's - showing 1 bar...15 minutes later camera went off, batteries died.  

Anyway long story shot, I looked at the Battery info on the Menu screen, both battery's showed 1 red bar on the Battery perfromance"...meaning  - "Battery has reached the end of its useful life, and should be discarded and replaced with a new LP-E6 battery pack."

Before the "cannot communicate" problem, I had 3 green bars on my battery performance. 

So to Mike at Canon that posted back in February, YES this affects the battery.

"I am not certain this is a "camera" issue.  :smileysurprised:  Well, of course it IS a camera issue because it shows up on the camera but I don't think it is the camera causing it. I have seen this on several different models. I am sorry I don't know exactly what works to correct it except new batteries."


I am going to repeat my post from long ago. This is only my 40 years of experience with Canon equipment. I am not a technician but this is what I have known. Possibly there is a large batch of faulty batteries out there (even Canon).

I discourage the use of 3rd party batteries ever. Strongly discourage it. Smiley Mad

Now I am sure there is that specific camera that has a flaw but I still will go with bad batteries.

EOS 1DX and 1D Mk IV and less lenses then before!

The "solutions" to this are so widespread. I have seen postings that new batteries will clear up this problem. I've also seen someone put the camera into the freezer for 20 minutes..this seemed to work (No way I was going to try that).  Cleaning the copper connections..that worked for some. Removing batteries and the small watch battery...another "fix." Can't say if this was a permanent fix for them or temporarly. But for many, like myself it needed a costly repair.


Look, I love my camera..I can't complain really, I have it since mid 2010 and this is the first problem I ran into.. I've seen many who only have had the camera a few weeks before this problem started. Even one who bought it from B&H, right out of the box the issue was there. THAT has to suck.. Inconvenience, yes. I guess the bright side for them it's under warranty.


Do I fear this issue will pop up again out of nowhere, I do.  I would like to know...from Canon, what is causing this (battery, faulty internal part..the firmware?) Why is it so common? I would understand a few cameras affected, but when you start typing  "cannont communicate..." into Google and it autofills the rest. Then you know it's a popular problem,


Heck let us know if there is something we need to do to perhaps prevent this again.