Sudden Electrical Failure After Bump Start

[CharlesK]

I've put a new stereo in my 9n today, and sorta ran the battery flat.
Anyway, I bump started it, first time forgot to turn the ign on then when I did start it, loads of warning lights came up on the dash.

Moved the car, realised there was no powersteering, brake servo wasnt doing anything, all interior lights and conttrols had died on me. Also, the Stereo picks up the voltage going to the battery, and when running will obviously read 13-14v, but when it was running this time, was barely above 11.

I swapped batteries over and then everyhting seemed okay, but still a really low voltage from the battery, seems liek its suddenly not charging, but the battery light isnt on.

Anyone have any idea at all what could have caused this? Car electrics are beyond me.

[oh, and had the headunit in my old car, always read acuratly on there]

[Rui polo Gti]

Have u checked the blade fuses on top off the batterie 40a u find it will be blow u put the leads wrong way?

[CharlesK]

It's only ever happened once. Not sure why. All the fuses checked out fine.