How long should a car battery keep charged before it goes flat?

How long should you be able to leave your car standing before your battery goes flat?


To keep mine charged I have to do a decent half hour journey atleast 3times a week, is this normal?|||Depends upon the age/capacity of the battery, climate, and condition of the cables.|||I assume you mean, how far do you have to drive to keep the battery charged? That would depend on how big your battery is, how much was taken out of it when starting..for instance, during cold weather, it takes a lot more current to start a car, and the battery has less power when cold.


I would think that a half hour of driving would replace the current taken out.





As for how long to leave your car standing...?? It could take weeks, to drain the battery, but this also depends on the condition of the battery and how big (how much capacity it has), along with what might still be using current inside the parked car. My girlfriends car has a self leveler that keeps the car level, and it runs even when the car is not running. But it started to run every twenty seconds and then shut off and then repeat this again and again, for some odd reason, and so, after a week or so of car being parked, the battery was drained.





But if you park the car for extended periods of time. like a few weeks or months, disconnect the battery from the car. Batteries will drain on their own also, just a fact of life, but if disconnected, they will last a long time before draining. Check it monthly, and recharge it so that it is ready to use.|||I have left a car unstarted with the battery in for over 2 months before and it still started. If there is no short in the system only something like the clock is pulling it down. Other problems are more likely to be a concern, like old fuel in the system going bad.|||A month before recharge or 2 months total flat.





With your condition - you have a problem of a parasitic drain or a weak cell in possibly an old battery.