05 CTS-V battery drain?
Posted: Fri May 17, 2019 7:04 am
In some ways it is surprising that this hasn't happened more frequently since the car obviously sits a lot. I don't always have the battery charger connected though. The battery that is in it was installed under Cadillac CPO in probably late 2010 so it is pushing 9 years of service (it is rated as a 6 year battery). To be clear, what I'm about to describe has never happened...
The car sat for probably 4 weeks without a charger which I would think is OK. I decided to connect my charger last weekend. It never left the first charging stage (red light blinking). At some point I opened a door for some reason and....dome lights did not come on. Went on travel...left the charger on. When I got back, the red and green lights were flashing alternately. Never seen that before. Disconnected and reconnected last night. Measured voltage on battery (while charging) this morning and it was like 5.5V or so. Oh god.
Finally I disconnected the ground side to isolate the battery from the car and in only a few minutes of charging the battery, the voltage had risen to over 10.5V. So not sure what is going on but it seems like a drain. I think the last time I drove the car was to bring your child to work day. It would really suck if Ian left a light on in the back or something. I guess I'll charge the battery up (seems like it will take a charge, even though I'm sure at this point it is compromised), reconnect it, and sort of see if I can figure out what is going on. If it was just a battery issue (i.e. shorted cell) it wouldn't act any differently disconnected from the car. So it seems like something on the car side drained it. To be continued after battery fully charges.
The car sat for probably 4 weeks without a charger which I would think is OK. I decided to connect my charger last weekend. It never left the first charging stage (red light blinking). At some point I opened a door for some reason and....dome lights did not come on. Went on travel...left the charger on. When I got back, the red and green lights were flashing alternately. Never seen that before. Disconnected and reconnected last night. Measured voltage on battery (while charging) this morning and it was like 5.5V or so. Oh god.
Finally I disconnected the ground side to isolate the battery from the car and in only a few minutes of charging the battery, the voltage had risen to over 10.5V. So not sure what is going on but it seems like a drain. I think the last time I drove the car was to bring your child to work day. It would really suck if Ian left a light on in the back or something. I guess I'll charge the battery up (seems like it will take a charge, even though I'm sure at this point it is compromised), reconnect it, and sort of see if I can figure out what is going on. If it was just a battery issue (i.e. shorted cell) it wouldn't act any differently disconnected from the car. So it seems like something on the car side drained it. To be continued after battery fully charges.