Battery Life When Car is Not Driven

My sister had some medical issues and i had her car at my house for many months, a 2011 Ford Fusion. Back in March I hadn’t been starting it much & the battery died and was replaced on warranty service. I was driving it maybe every 3 - four weeks. It died again in the summer & I had to jump start it. A few weeks ago I started it & just pulled it up my driveway to change her cabin filter. When I was done it wouldn’t start again & I had to jump start it. It’s under warranty & they replaced the battery again. The service guy said with all the computerized things on cars these days there is always something draining the battery & it should be run every week for at least 30 minutes. I have some problems with that figuring it is such a low current drain the car should go many weeks and the battery still be good. Looking for some feedback on this subject.


Yes the mechanic is right. Even when “off” there is a small drain on the battery. Batteries are pretty small these days to save weight so you may be seeing the effects. It is easy enough to test the drain when off and I’d expect the tech to do this before giving you a free battery.

If the car is parked near an electrical outlet, go buy a small 2-amp or so charger/maintainer to attach to the battery and pug in. Leave it on the entire time parked and the battery will be just fine when you need the car. They are pretty cheap at your local big-box retailer or auto-parts store. Collector car guys do this all the time for cars not driven daily.

When a battery is fully discharged it will deteriorate quickly if not recharged. I have a couple of cars that if they are not run for 3 to 6 weeks the battery will not be able to start the car. I use a trickle charger or a battery tender charger on these cars when they sit for long periods.

In your case the battery is discharged and when you drive it the running time is not enough to fully recharge the battery. Cars really are not designed to just sit, they are designed for regular use. If you continue to care for this car I’d recommend getting a battery tender charger and use it for a few days every month if the car isn’t driven. Another strategy would be to park one of your other cars for a week a month and use the Fusion daily for a week or so.

I think a “Battery Tender” would be the best choice, it won’t over charge the battery but it will keep the battery fully charged and ready to go.

The mechanic is right. My niece left her new BMW X3 in long term parking when she went to Germany. When she returned a few weeks later…the battery was nearly dead. Several other people were in the same boat and the wrecker driver that jumped her vehicle got a windfall of customers. To echo @UncleTurbo…vehicles are designed to be driven.

I think the mechanic is closer to correct than you are. You could probably go two weeks or so with most cars, but some cars might not make it that long. You’re lucky that these batteries have been covered under warranty, as this isn’t a defect. I agree with the others that you need to use a battery tender (or disconnect the battery); this should also keep the alternator from wearing out early.

you can do following, drive the car for 2 to 3 hours and when you park the car just plug off the battery cables

Go to amazon and get a ‘battery tender’ and use it, that’ll solve the problem.