Laertes

Need help. Have an event tomorrow, went out to prep car and the battery is completely dead. I last drove it about two weeks ago, and very stupidly neglected to replace the battery maintainer. Now it's completely dead. No lights on dash or anything. I've plugged the battery maintainer/trickle charger into the accessory cigarette lighter plug, and now get flashing interior lights and clicking sounds from the doors, maybe the window motors trying to lower the windows the few millimeters since the doors are open?

Anybody have experience with this? Will my CTEK battery maintainer charge the battery back to life? Will I have error messages that will need to be cleared by the dealer? It hasn't been cold and my car is in the garage, so no risk of the battery freezing. I know it's really bad for the battery to be discharged completely, but is it likely it will recover or am I going to need a new one?

Thanks.

NorthVan

It won't charge it enough, give it a boost, and drive it around a little.

drl

I killed my battery leaving key in ignition and trickle charger brought it right back to life. Car started, drove it a bit, no further issue

CRex

Best way to recharge is by driving. Trickle charger doesn't quite do anything beyond maintaining a given battery level...

Laertes

OK. Battery maintainer successful in getting enough juice in to open front trunk; then successfully got it running via jump start. Initially had PSM and PASM errors (as the manual said I would) but those cleared quickly while driving; however, the TPMS now won't work at all. I re-input all the parameters in the instrument display to reset it, but it never gives me the "system learning" message and just gives me the warning light. Anybody ever had this happen after a battery issue? Strange. Looks like a trip to the dealer is in order....

Igooz

Yes, I have a lot of experience on this. The CTEK will charge the battery, but it will take it about 2 days (or so) and the CTEK unit will get nice and hot while working so place it some place accordingly. Ideally disconnect the battery and let the battery get fully charged. The open load battery voltage should be back to around 12.6-12.8v (no load, no charge) to have full SOC.

CTEKs do charge batteries, but they are "tirckle" chargers so it takes a while.

Lead Acid battery (assuming that's what you have) do not like to be deep cycled. IE) discharged all the way down as they lose their "life", so put a short harness on your battery and leave it on the CTEK whenever you are gone for an extended period.

As far as TPMS, they are supposed to "recover" and figure things out after you reset them. Good luck!

NorthVan

I haven't had an issue with my TPMS, but have had other issues on my 06 C2S when the battery died. Took it to the dealer and they recharged my battery while they disconnected the terminals. They told me that it essentially shut down all the computer systems in you car, and then brought them back up when they reconnected the battery. Your TPMS system has likely had a brown out, and never true shut down, so it won't restart it's self again. Try disconnecting the battery for 5 minutes, it should restart everything.