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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,



Just thought I'd add that I had the battery board replaced and camera cleaned.    It feels like new and works the way it ought. Though a bit of a wallflower now that the 7D2 is my favourite new toy.   Am loving the AF system.




I had the same problem and brought my 7D to Canon.


I had to pay USD 95 and they replaced the DC current with the new one.


It is solved now and no problem at all although I am keeping the battery inside all time.




Here is my experience:  I dropped my EOS 7D into the hurricane Harvey flood, got home and tried to turn it on after several days with a different (i.e. dry) lens.  Nothing happened - the display on the back remained dark and the camera was silent.  I bought a new (second hand) 7D camera and tried the original lens and the lens did not autofocus.  Bought another lens.  I was able to use the flooded battery in the new camera and it worked fine.


After four months I put the original lens on the new camera, lo and behold, it evidently had dried out and it worked perfectly!


So now I tried to put the battery from the new camera into the original camera.  When I turned it on I got the "Cannot communicate with battery" error, but when I hit the "Cancel" button I was able to bring up the camera menu on the LCD.  However I am unable to take a photo.


In my case the problem is therefore with the camera, because I am able to use all three of my batteries in the new camera and none of them work in the old one.


At least the lens recovered from my stupid mistake (falling into the flood waters), but the camera shop still thinks the camera may not be worth repairing. I hope this info helps somebody.




I spent 10 weeks doing disaster response in Puerto Rico and St. Croix, I left my 7D's at home, brought a less expensive camera, unfortunately, the photos don't compare.


I used to have a company's name, found them on ebay, and they had lots of circuit boards and canon parts, don't know if they were new, pulls, etc.  Have you tried doing a complete reset of the camera, even removing the coin cell from the battery compartment?  Usually the problem I've found with batteries not working in a camera is that they are aftermarket batteries.  If it can not communicate, and you tell it to work anyway, usually the only problem is you can't see the battery gage, so in your case, I have to wonder if the battery was really charged, have you checked it with a meter?  Meters may not give true readings as they don't put a load on the battery, but if the voltage is low, then it's low, the false reading would be if it show full voltage with no load but once a load is applied, the voltage sags.


I've had the occasion to repair a canon lens or two, for a lens, there is a lot of electronics inside that lens barrel.  I took a lens all apart in a motel room on the bed, used my cell phone to document every step of the way so I could get it back together.  You were lucky that the water all evaporated and left no conductive deposits.


I was at Hurricane Katrina, with my canon power-shot, out doors took fine photos, once I got onboard the ship, a navy assault carrier, well air conditioned, moisture inside the camera would condense and killed the camera.  I had to ship it back to canon for repair. I've heard some people will put the cam in a sealed plastic bag, also having packets of silica gel helps.


I don't know if I'm helpful or not, if I can help though, let me know.