Husband thinks charging phone drains car battery
Dear Car Talk:
My wife has a 2010 Chevy Suburban that I had to replace the battery in recently. The old battery was only four and a half years old.
I suspect the cause of the battery’s premature demise was because she leaves her phone charging cable plugged in to the power port continuously. I see that the tiny power light to the cable stays on even with the ignition off and the key removed. Could that small power demand weaken the battery even though the vehicle is driven daily? She says that’s bunk. What do you say? – Jerry
RAY: We’re with her. The average battery lasts about five years. So yours lasted a little less than average.
You bought this Suburban in 2010, so I’m guessing you’re now replacing your second battery. In other words, you’re right on schedule. And the phone charger is irrelevant.
First of all, a phone charger that plugs into a power port typically draws about one amp. And it’ll only draw that one amp if there’s a phone that’s actively being charged. Otherwise, all it’s drawing is enough power to light up that tiny green LED that tells you it’s plugged in. That takes a fraction of an amp.
To give you some perspective on how much power she’s using with her unused charger, it’d be the equivalent of pulling over once a day and leaving the emergency flashers on for 10 seconds.
It’s almost nothing. It would be completely replenished once the car is started again, and it would have a negligible effect on the life of the battery.
Now Jerry, you haven’t actually accused your wife of shortening the life of her battery with this phone charger, have you? I mean, out loud?
Oh, you have? That’s too bad.
Well, you owe her an apology, then. Put your tail between your legs, tell her you were completely wrong, that she did nothing to wear out the battery, and start looking for some gourmet recipes you can cook for her in the next few weeks.
And here’s a tip: Don’t tell her she needs to extinguish the pilot light because it’s wearing out the stove prematurely.