Battery draining over a few days

[DSYKES5500 22]

Hi all, 

My battery drains to a point where the car won't start over the course of three days. I can't see anything obvious like the boot light, glove box light stuck on. I've removed all the interior bulbs and taken out the inline fuse for the alarm but the problem remains. I've also tried a new battery. Is there a typical known 205 issue that could cause this?

 

Thanks

[Tom Fenton 1,650]

It has always been something aftermarket for me. Stereo or alarm etc. What I would do is physically disconnect the battery, Measure voltage, leave it 3 days, then measure again. If it’s good it shouldn’t drop much. Reconnect and try to start the car. I say this as even though it’s a new battery it’s not guaranteed to be any good.

[DSYKES5500 22]

Good idea Tom. I'll do it tonight, it's forecast rain for the next few days so it's the perfect time. Thanks!

[Atlaskrukvaxt 5]

If your battery turns out to be okay the first I'd check is the stereo. Stereos have a constant power cable and a cable connected to the key switch. Make sure these aren't swapped around.

[bacardincoke 48 1 Cars]

I'd a similar situation when I got my car and went through the potential fixes you mention, but with no success.

 

Long story short it was tracked down to an intermittently faulty starter plus a previous owners workaround to either fix or mask the problem.

 

It's documented here - https://www.205gtidrivers.com/forums/topic/173878-unidentified-non-factory-wiring/

 

If all else fails may be worth seeing if the same guy owned your car!

 

I'm new to all this electrical stuff, just picking bits up as I go, but found this wee table on battery condition while Googling and found it useful (if it's accurate?)

 

Battery Voltage and State of Charge:

12.66v . . . . . . . . . . 100%
12.45v . . . . . . . . . . 75%
12.24v . . . . . . . . . . 50%
12.06v . . . . . . . . . . 25%
11.89v . . . . . . . . . . 0%