Lockdown electrical issues

[mark674500]

I've a 09 plate 2.0 TDI, that has been barely used during lockdown and the battery keeps going flat.    The battery was replaced before lockdown, but was slightly lower than the recommended capacity for the car.  The supplier reassured me that it would be fine, and when the car was used daily it was. 

 

The battery has been going flat when the car is not used for a period of weeks which I guess is understandable, but I think it's getting worse.  It's been tested and came out as OK.  The car is supplying charge.  On Saturday the battery was so dead that I had to use the bypass switch on the starter battery pack to get it started.  It didn't like being started this way and the hazards were stuck on for a good 10 mins, but I assumed this was as the CPU didn't have it's normal startup sequence or due to low voltage on battery.  I drove it for an hour and they came on again partway through the drive.

 

Today, just three days after it had an hour's drive, the car won't start and the power is flicking on and off, it sounds like a relay is struggling to stay in the right position.

 

The only modifications that may be drawing power are a USB power supply instead of the lighter socket, which has it's own switch so does not draw power, and a reversing camera which is switched on from the reversing bulb via a relay to isolate it from CANbus.

 

Is this likely to be just needing a new battery, in which case I'll get one of the correct capacity?  If so, is it necessary to keep the car connected to 12V whilst I change over to a new one?  I thought that it was required for alarm codes etc, but of course if the existing battery had gone flat then it makes little difference.

 

Thanks in advance for your advice, and please feel free to point me to other threads.

 

Mark

 

PS the car is being traded in soon so whilst I want to get it going OK, I'm also after an affordable solution

[PipH]

Batteries don't like going flat & can be permanently damaged.

 

Are you able to connect a battery conditioner charger or trickle charger for a few days?

 

If so, charge the battery for 2/3 days.

 

Then check the battery voltage with a meter after a further few days standing, before trying to start it & let us know the readings.

 

You don't really want to spend out on a new battery if this one can be recovered.

[langers2k]

Disconnect the battery

 

Make sure it's charged up before you trade it in, simples

 

[jong123]

ive had this for the 8 years I've owned mine, wont start after 4 days, during lockdown I have wired up a charger to a time switch that charges for an hour every other day, works for me.

[mark674500]

Just now, jong123 said:

ive had this for the 8 years I've owned mine, wont start after 4 days, during lockdown I have wired up a charger to a time switch that charges for an hour every other day, works for me.

That's interesting to know - thanks for the idea!

[mark674500]

8 minutes ago, jong123 said:

ive had this for the 8 years I've owned mine, wont start after 4 days, during lockdown I have wired up a charger to a time switch that charges for an hour every other day, works for me.

PS - do you leave the battery connected to the car whilst charging?

[jong123]

I run an extension lead from garage to car to a charger placed onto the upturned battery cover in the space behind the nearside headlight, charger is connected to terminals. the extension lead is visible as it is routed from the wind screen scuttle, so I know to remove it before driving.

Works for me.

[FatblokeVRS]

I was thinking of getting one of these batteries when mine starts to cause issues. Its 190mm high instead of the 175mm high thats currently in but looks like there's plenty of room.

 

https://www.tayna.co.uk/car-batteries/exide/ea770/

 

 

Edited 24 January, 2021 by FatblokeVRS