Originally Posted by vroooom ptssssh
I find that if you connect the jump leads, turn the ignition on the S1 with the jumper car running it will take about 10-15 mins for it to even turn over fast enough.
Thats probably more caused by poor jump leads just for info
If you have to leave the battery connected for a while you are charging your battery from the fresh one, the jump leads most likely can't handle the current your starter is trying to pull.