Over Charged Battery, what did I damage?

[Reducer]

I have vision plus, lost my charger, so I hooked the battery up to a car battery to charge, this worked a couple of times no problems, I had a 12v car battery charger on the the car battery while charging the phantom battery, :[ battery seemed to be charged ok, turned every thing on as usual, no camera now, no light on camera, app connecting to repeater, I checked battery voltage, its 14v, what did I burn up?, how much is my stupidity going to cost? thanks.

 

[Reducer]

Update: I figured whatever damage was done was done. so I flew it a bit to discharge the battery, after a bit of flying I noticed the light on the camera was back on. shut it down and started the app to see if it was working, got the not the correct battery message, restarted everything, now everything seems to be fine, pluged it into the laptop and all seems to be ok, except under advanced it is saying I have a 6500 mah battery, it is a 5400 mah battery, I ran it down to 25%, I am now recharging off a 12v 7a gel cell with no charger, anybody ever tried to charge a phantom 2 battery like this?,