Motormouth: More on Subarus' battery problems

Q: Recently a reader wrote in about their 2017 Subaru Forester and the battery dying. I work for a company that has dozens of these 2017 Foresters and we have had battery problems (and replaced them) on several of these vehicles. My guess is that there is a battery problem that Subaru isn't owning up to. For what it is worth, our vehicles experience high highway miles so the short trip factor isn't applicable.

N.L., Homer Glen, Ill.

A: You make a good point. Sometimes carmakers will install the least expensive (read smallest) battery necessary. Read on.

Q: I own two Subarus and have experienced the battery draining issue on the one with keyless ignition. After the battery draining problem happened two more times on two consecutive days, I did more research on the issue and found that Subaru and automotive stores sell an upgraded battery with a higher CCA rating.

Armed with this information, I had a frank discussion with the service manager at the dealership who finally agreed to install the upgraded battery at no charge. That solved the problem. It has been a year and a half with no battery draining issues.

W.R., Chicago

A: It never hurts to have a friendly chat with your service manager. Ask to speak with the service manager, not the service writers at the front desk.

Now I have a Transit Connect passenger van, and the battery is hidden under the firewall under a solid plastic cover. It's very difficult to connect anything to it. Is there such a thing as a solar-powered battery maintainer that I could leave lying on my dashboard and leave plugged in to the power socket on my center console?

M.K., Elkhorn, Wis.

A: When a battery is difficult to access, there is usually a provision to conveniently attach jumper cables or a battery charger. Check your owner's manual and you will probably see that there is a positive (+) connector access under a cover near the underhood fuse block. Yes, there are solar-powered battery maintainers, but in my past experience, they don't work very well, especially on cloudy days. There are now probably better units, since our last experience was several years ago.

Q: I know it's not good for your battery to let the car sit for long periods, so I would like to know how much driving is enough to avoid problems. I recently retired, and instead of spending lots of time commuting, my car spends a lot of time napping in my garage or going on short trips. Sometimes, I don't drive the car for two or three days, and once a week, I drive about 10 miles round-trip, mostly on an expressway. Is that enough to keep the adequately battery charged?

What about in winter? When it was bitterly cold, I tried to run the car at least once a day (driving slowly) for 20-30 minutes. What do you suggest?

A: A 10-mile drive probably takes about 15 minutes and that is usually enough to keep the battery charged, even in the winter. If your car has a voltmeter, it should show at least 14.2 volts necessary to charge the battery.