12volt car charger & charging batterys

[Bones]

In the old days you could just charge them with a 12volt car charger and when they were done you could tell by the multi meter .
can you still do that ?

were can I find more info on charging batterys ? any helpful sites ?

[Randy]

i ' m not to sure on this . All i know is i hook my charger up to my car ( 71 Superbeetle ) battery and it charges my rc battery , but it drains my car battery .