Mercedes SLK World banner
Status
Not open for further replies.

Need some help guys

2K views 8 replies 5 participants last post by  Livefreeordie 
#1 ·
I have a problem keeping a charge in my battery. A little history; over the winter i took the battery out of the car and placed it on a trickle charger all winter. This past month i took the car out of storage for the season, ran the car at idle for an hour then took it for a short ride. One hour later the battery was dead, i took the car to a local parts store and had the charging system tested, all was good. I had the store charge the battery, went home and it was dead. i checked all cables and all looks good. Either the battery is dead (2 years old) and the test was done wrong or there is somthing draining the battery fast. Any ideas??
Thanks
 
#2 ·
Is the battery case cracked anywhere? Can you check the water levels in the cells? If so are they low?


If you fully charge it on your trickle charger while disconnected from your car, and then let it sit off the charger overnight (and not connected to your car either), then reconnect it to the car and check to see if it is dead then or not. That should isolate whether your car is draining it fast or if the battery won't hold the charge.
 
#4 ·
Is the battery case cracked anywhere? Can you check the water levels in the cells? If so are they low?


If you fully charge it on your trickle charger while disconnected from your car, and then let it sit off the charger overnight (and not connected to your car either), then reconnect it to the car and check to see if it is dead then or not. That should isolate whether your car is draining it fast or if the battery won't hold the charge.
No cracks in the case and the water level is good. I will try charging the battery and let it sit overnight. When they checked the battery they set the machine for 1200 cold cranking amps, that sounds wrong 1200 should be for a deep cycle battery.
 
#3 ·
Wasn't there a post on how to find out if some on-board device is drawing too much from the battery?

IIRC (really fuzzy memory), it was something simple: a DC light bulb placed between the negative post of battery to the negative ground/chassis. Or use an amp meter. If there is an usual power draw, then pull fuse one at a time to isolate the device that's drawing too much power. I cannot recall the milli-amp allowed when all devices are asleep. (Please correct me or post a link to that post, when found)
 
  • Like
Reactions: -1-
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top