My son is out of the country for 5 months. He asked me to start up his car every couple of weeks to keep the battery alive. I tried after 2 weeks and the battery is already dead! Should I jump it now and try and keep it alive by starting it up every week or can I just leave it dead for 5 months? Which would be better?
If the battery completely drained down w/in 2 weeks then the battery is likely a goner already. If he really wants it to survive and keep it going it would actually be best to buy a good charger - I have one that I can leave a battery on and it automatically monitors and maintains the charge. Or there are various “trickle chargers” that are meant to maintain batteries over a long period of sitting.
But, aside from that, the best thing to do is not just start the car once in a while. Rather it should be driven once in a while. When you let a car just sit for a long time the battery is the least of the trouble (they are not very expensive to begin with and easy to maintain without a large investment). Five months isn’t really all that long, but even so it will be better to take it out for a long drive once in a while.
The battery may already be gone, but if you leave it discharged for much time, then it will be damaged beyond recovery. I would get a battery tender/maintainer to keep the battery up, if it is not too late.
I have a car that I park every winter (about 5 months). I put a battery maintainer, and the batteries last just fine. An alternative is to buy a small (1.5 amp) charger and throw it on the battery every week or so for a little while.
Sounds like the battery is shot or there is a parasitic drain that is discharging it. You could remove the battery from the car and have it charged and tested or just wait until your son returns and let him deal with it. If the battery takes a charge, leave it disconnected so it will STAY charged…
The longer a battery is left discharged, the slimmer its chances are to recover. Batteries do not tolerate being stored in a discharged condition very long…