today after powering up i revieved the Battery Cell Broken message, this battery is 10 times charged, anyway i  plugged in and out several times but the error stll exists... I took another battery and did my flying. When getting home i inserted the 'broken"  battery but no message anymore, everything seems fine...duhh ??? So i did a short nearby flight with it..nothing wrong. This battery is 8 months old. so no warranrty anymore.. Can i still used it?? So maybe nothings wrong but te software was wrong?

You might consider to give the deep discharge / recharge cycle to both watch how it behave but also to make sure all cells get a fresh balance.
Use up the battery flying low nearby until only around 11% batt are reported then land and let it use up the remaining batt. You want to have it below 8% (i usually aim for 5% but have been as low as 0%), make sure it get airflow while it is standing there.
When batt has cooled for an hour recharge it fully let it rest/cool for an hour once more and then check the status in the app, hopefully the cells keep equal, for the prize those batteries should last for more than 10 times charge.

Thanks  , ill give it a try.

You can also upload the flightrecord from the 'short nearby flight' and see what it says about cell deviation.

One way is uploading it here:
http://www.phantomhelp.com/LogViewer/Upload/

Anothere is here:
https://app.airdata.com
Go to Power > Battery Cells...

Yes, please manage a battery full discharging and charging circle and restart the drone. If the issue persists, are you located in the Netherlands? If yes, I suggest that you try to contact our support for further help. http://www.dji.com/support