I live in the mountains of Colorado and will be leaving my car at work during the week while I take the bus to and from work. How often should I start my car midweek (if at all) to keep the battery happy so I can drive it home on the weekend? How long should I run it and must I drive it or can it just run in the parking lot? Thanks for whatever help you can give!
Just leave your car be during the week. Cars can sit a few months before any ill effects to them and minor ones at that.
Just let it sit. It should be fine. If it is not, there is a problem somewhere that needs to be addressed.
I wouldn’t Run It …
… during the week. It’s not necessary. Your battery will be happy to start your trip home on the week-end.
In my opinion, if you do need to run it during the week, it’s best to drive it long enough to get it up to full operating temperature (10 to 20 minutes), rather than just start it for a minute and shut it off. Short runs will add undesirable combustion moisture to your engine and exhaust system that won’t be evaporated away as it would be by a fully “warmed” engine/exhaust system. Combustion creates water, which you see dripping (running) from the tailpipe of a recently started car in the cold of winter.
A properly functioning car can sit a week or two or three and fire right up, no problem, even at temperatures below zero. You didn’t introduce your car. We are talking about a properly maintained car, right?
Question; why not leave the car at HOME and take the bus?
Assuming your battery is in good shape now, don’t start the car mid-week. A good battery will hold a charge much longer than 5 days with no problems. Starting the car and running the engine for a short period is not good.
When you drive on weekends, make sure you drive long enough for the engine and drive train to warm up fully. Driving for only 10 or 20 minutes the whole weekend might not be enough, and eventually the battery will weaken.
Another option is to hook up a Battery Tender when the car is at home. A Battery Tender will maintain the battery at full charge without over-charging it.