Hello everyone, ive been left in charge of my girlfriends fathers SL500 AMG while he's in hospital being treated for cancer. before he went in he put a solar trickle charger on the battery in the engine bay - this hasnt really worked as i wont turn over now plus the electrics are now doing some crazy things and im thinking the trunk battery needs charging now too. Is it ok to just out a normal charger on this or do i need to get the professionals in?

many thanks,

Sam

 

i have been using battery tenders on my 03 sl for a couple winters, i dont think the solar trickle chargers have enough current output to dependably hold the batteries up, particularly if the batteries are getting some age on them and the trunk (appliance) battery is constantly loaded at a few milliamps to keep certain onboard systems with memories etc running..

i recommend small 2-3 amp charger/tenders...available from wal mart for around $20 each. they will charge slowly and then float maintain the batteries at around 13.2 volts which is what a lead acid unit wants to see in resting situation.

i also connect the charger to the batteries before plugging the charger in especially if the battery is deeply discharged, this prevents a high current inrush if the charger capacitors are fully charged before connecting them to the load.

at 2-3 amperes it will take a bit of time to bring them back up but perhaps in 12 to 24 hours..
you might wait for further input from others that have had similar experience before taking the chance on your own.
glen