Help - battery issue no crank

[Gazdkw]

Car had a flat battery today. Its done this a few times if I don't use the car for a day or so.

I tried th normal thing of jumping the with my wife's car. This time round I was a donut and connected donor cars negative to dead cars live and donor cars live to dead cars bodywork. It did spark a little and I quickly realised....

Anyway, changed the leads round and the dead volvo battery reads only 12.2-12.8 when connected to the donor car as above and only 11.2-11.9 if I disconnect.

The problem is, it's not even trying to crank. Radio, front lights, sat nav all have power but when I try and start it does nothing. I have checked all fuses I can find and they all seem good. Also, the volvo has swallowed the key and won't give it back...

Any ideas??

[100K+]

Is the wife's car ok??. I'd try and recharge the Volvo battery for 24hrs and see where you go.
Cheers Bob

[Gazdkw]

Yeh her car is fine.

I have been and brought a power jump pack (noco gb40)

I have just tried it and it did try to crank but didn't start. The power pack needs charging I think. Coming up with all kinds of errors now on the dash....but....at least its trying to crank and I have the dash display back, and I have the key back

[Gazdkw]

It's working. Charged the battery for a few hours and it started.

I have an amber engine management light on the dash now though. Hoping that will pass resolve itself.

I need to figure out why the battery is draining. It seems to be if I don't use the car for more than 3 days or I do 3 or 4 days if short trips on the bounce.

I checked the voltage when the car was running and its 14v. 12.9v when not running. Think that confirms the alternator is OK?

[GrahamBrown1]

If you put the battery on a trickle charge for a good day this may help to bring it back to health. Some smart chargers even have a recovery mode. Then when charged get it tested. It may be that it just requires a new battery.

If the battery tests good and it still goes flat then you have a draw on the system such as a module not shutting down ect. This can be generally not to bad to find with the use of a multimeter and In some cases tho more for a garage a thermal imager.

[Gazdkw]

The battery is only a few months old. It was a replacement for a battery that was within warranty and had failed (Sam's issues as I had today).

I have a decent multimeter. I am assuming you just check for a draw when the car is not running and locked?