How to keep car battery charged?

ripplyuk

I’m having surgery soon and won’t be able to drive for at least 4 weeks after. I have no one else who can drive the car so I’m wondering if the battery will run down. I thought I would just start the car up every few days and let it sit idle for a while but now someone has told me that the car actually needs to be driven (wheels turning) to get it to charge. Is this true? Is it to do with distance?

twhitehousescat

do you have access to a 13a socket?

ps you will take more out of the battery by starting it , that you will put back in after a dew minutes on idle

repeat do you have access to a 13a socket?

casseus

disconnect the negative on battery

twhitehousescat

casseus wrote: »

disconnect the negative on battery

is the correct answer , that in itself will stop the battery discharging :rotfl:

Norman_Castle

It will charge while idling but to put back the energy used to start the car it will take a lot of idling. It will charge quicker while driving due to the higher engine speed.
A healthy battery should hopefully be low but ok after 4 weeks possibly needing a jump start then getting regular use again. Have you got breakdown cover?

Last year I was given a solar panel which I used through the winter in my irregularly used car which I believe helped.

onomatopoeia99

ripplyuk wrote: »

I’m having surgery soon and won’t be able to drive for at least 4 weeks after. I have no one else who can drive the car so I’m wondering if the battery will run down. I thought I would just start the car up every few days and let it sit idle for a while but now someone has told me that the car actually needs to be driven (wheels turning) to get it to charge. Is this true? Is it to do with distance?

Old alternators like the Lucas ACL / ACR put out very little charge at engine idle speed. Modern ones are rather better and do charge at idle.


Better to use a battery conditioner if you have a mains socket nearby, or solar charger if you don't. Disconnecting the battery terminals will also allow the battery to hold charge longer, but even doing that experience suggests it will go flat eventually.

Scrapit

4 weeks? Leave it. Shouldn't run down in that time and if it does it needs replacing.

Gloomendoom

I leave my car hooked up to one of these when I'm not using it...

https://www.ebay.co.uk/itm/NCS-MOTORCYCLE-SPECIFIC-SMART-12V-ACID-BATTERY-CHARGER-OPTIMISER-MAXIMISER/200905657536

casseus

twhitehousescat wrote: »

is the correct answer , that in itself will stop the battery discharging :rotfl:

Not in itself it wont, and I bet you didn't know but when you disconnect a battery negative terminal it stops all power to the vehicle like the clock and modules that require a constant live.

So if the batter discharges when its disconnected its because the battery needs replaced or extreme weather killed it.

twhitehousescat

after serving many yrs in the auto electrical trade I know that the average battery looses about 1ah per day in normal discharge

if the OP was to return and state he has access to a 13a socket I was going to link him to a nice maintenance charger that happens to be on a black friday sale at amazon

but he hasn't , so I wont

ripplyuk

I don’t know what a 13a socket is and I don’t want to start fiddling about with battery terminals when I haven’t a clue what I’m doing.

I had the battery tested and they said it was fine so hopefully it will last 4 weeks. If not, I’ll just have to get someone out to jump start it. I do have breakdown cover so I could ring them.