How Long Should Car Battery Last When Not In Use?

[Dani Boi]

I'm currently not driving my R33 as I have another car. The battery was replaced 6 months ago with an RAC one. I only drive it maybe every 5-7 days for 10 minutes or so at 80km/h roughly to get some charge in it but this is the second time the battery has died on me for leaving the car for 7 days. Is this normal?

[34GeeTeeTee]

Buy a trickle charger and keep the battery conditioned? Also saves you having to jump it if its left for a while

[Sklyn]

That amount of driving will not get any charge into it at all.

[niZmO_Man]

Disconnect it or trickle charge.

[Jordy32]

I drive my 32 every 7-10 days and it's never a problem

I'd suggest taking it for a longer drive, disconnect it, or purchase a trickle charger

[djr81]

I used to have the same. Batteries die when they stay low on charge.

Easiest fix was to go down to supercheapauto (or similar) and get a solar panel trickle charge thingo.

http://www.supercheapauto.com.au/online-store/products/SCA-1-5W-Solar-Trickle-Charger.aspx?pid=292829#Recommendations

Problem solved.

[260tech]

What he said. Trickle charge via solar. If you decide to do this then trickle charger needs to supply a similar amount of energy/current measured (calculated) over a 24 hour period that is drawn off by your connected accessories of course. (Real solar panel performance is another can of worms btw). If you decide to disconnect for longer idleness then make sure battery is fully charged first. (90 ~ 95%). This could take 48 hours or more. Caution, basic chargers can do terminal damage to your good battery (plates buckling/sulphating) if you leave it on charge for too long. Most charging to get you going will only bring the battery up to ~ 70% within 6 ~ 12 hours & a nice green light on your battery charger which is enough to kick engine over with reasonable spark but it is not really enough charge for storage purposes or laying around idle running clocks, immobilisers & other accessories without daily boost from driving. Once fully charged it (battery) will/should happily sit for up to 6 months in your engine bay or somewhere else, out of the way of little fingers in a milk crate off the floor/concrete.

My 2c.

Cheers, GW

[Kinks]

Disconnect it or trickle charge.

+1

disconnected battery will last 6 months before needing a topup.

also, once lead acid batteries go flat, if you have left it flat for a while it will sulfate. sulfated batteries have reduced capacity and are essentially rooted (they will simply keep going flat). they like being stored fully charged. even at 50% charge they will slowly die.