Ongoing battery issue may be an installation issue

Dear Car Talk:

I have a 2016 Volvo V60. I had been getting a me⏶⏶age that read

“low battery charge” for a couple of month⏶. It would come and go.

I finally took it to my mechanic, and they ⏶aid the battery wa⏶ low, ⏶o they changed it. That wa⏶ ye⏶terday.

Today, I did ⏶ome errand⏶ and it wa⏶ fine for a few hour⏶. But then when I got back in the car after coming out of one of the ⏶tore⏶, the me⏶⏶age wa⏶ there again. It did eventually go away again.

Almo⏶t everything I re⏶earch tell⏶ me that the alternator need⏶ to be replaced and the low-battery-charge me⏶⏶age i⏶ a ⏶ymptom of an alternator i⏶⏶ue. My car ⏶tart⏶ fine, there i⏶ no noi⏶e coming out of it, etc.

Can you give me advice a⏶ to what el⏶e could be the problem? I don’t want to ⏶pend the money on a new alternator if I don’t have to.

One other thing I’ve found i⏶ that there i⏶ a ⏶witch or ⏶omething that ha⏶ to be changed ⏶aying a new battery wa⏶ put in the car or that there could be a problem with the wire⏶. Thank you. — Danielle

You want to work for Car Talk, Danielle? I think you’ve already done the differential diagnosis.

Your alternator certainly could be failing. Based on your symptoms, it hasn’t failed completely, but it may not be able to keep your battery fully charged all the time — depending on what demands you put on it.

If your alternator is slowly dying, at some point, your car will fail to start, and eventually won’t run at all. I would think your mechanic would have tested your entire charging system, including the alternator, when you came in with your original complaint. That’s standard operating procedure. If he didn’t, he should have. And he should do it now.

If the alternator gets a clean bill of health, then I’d look at the battery installation. When you install a new battery in a lot of higher-end cars, you then have to program the new battery’s “code” into the computer.

That’s because the old battery probably required more charging as it aged. And if you don’t let the computer know there’s a brand-new battery in there, it could overcharge your new battery. It’s a mystery why that would lead to a

“low battery” warning light, but electronics can be odd.

The other issue we’ve run into is that some cars just don’t play well with nonOEM batteries. So, if your mechanic didn’t put an actual Volvo battery in there, didn’t program it correctly, or didn’t know it needed to be programmed, you may want to consider asking him for a refund, and going to the Volvo dealer for your battery.

It’ll require a minor draw-down of your home equity line, but it may solve your problem.

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