I can't tell you how happy I am that you brought up this subject. I have a friend who owns two vehicles. He has put a vehicle battery charger on each of them since new. I believe both are 2013 models but am not positive. One is a Ford and the other a Jeep Grand Cherokee. The battery on the Ford recently died while he was shopping. He called AAA and they came to jump start the vehicle. He purchased a new battery for that vehicle and then purchased a new battery for the Jeep as well. As I said he keeps one or the other vehicle on a charger when not in use. He now has a battery charger on the brand new batteries when not in use.

I have owned a number of vehicles and have never put one on a battery charger. All have started up right away even if I have not driven the vehicle for maybe three weeks to a month on one occasion.

My friend and I have had discussions where I have told him I did not think the battery charger was necessary. He insists that it promotes longer life and keeps the batteries in better condition. My experience points to a different conclusion. Can someone give me the right answer or is it one of those things where, it depends? Presently we ar in So. CA but my vehicles are generally in much colder Western states, CO, ID and WY.

Dennis

I will just note that my MB still has the original battery after 14 years. I attribute that to several things: the battery is in the trunk where it stays cool (why don’t all manufacturers do that?), it has a low voltage cut-off that prevents deep discharge if you leave an accessory on (they should do that too), and it uses the same large AGM battery that is in the diesel engined cars. A replacement is almost $300 (remember when batteries cost $30?), but based on past experience, I’ll buy an OEM MB battery when this one fails.

Yep. For Prius owners here:

Prius models need to be driven weekly for about 20 minutes to keep the high voltage traction battery and the 12-Volt accessory battery charged.

If a Prius has a “smart key system”, it can be disabled with a button under the dashboard. That makes it easier on the 12V.

Getting into a locked Prius requires a manual key. Getting to the 12V requires crawling over the back seat, removing a mat, lifting a flap, pulling an emergency hatch release, and then removing everything from the trunk to get to the right wheel well.

Changing the 12V is easy. Videos are on YouTube. (I’ve done it several times.) The battery is $200 to $240 because it’s an AGM type. But new OEMs have seven year warranties. Most last 5-10 years if treated properly. (i.e.; don’t drain them deeply!)

I drive a Prius. I got one in 2005 and used it for commuting to work until I retired. Then I used the truck primarily because my clothes were frequently covered with noxious materials from the farm and I wanted to keep the Prius for the family car. The car would sit for a month at a time before I ran it occasionally in the summer (my wife had her own car which she preferred to drive). The battery died twice in the 12 years I had that car. The first time AAA took care of it. The second time I climbed over the back seat to open the hatch. I had to unload a lot of stuff to get at the release. It really would have been nice if the hatch could have been opened with a key. Supposedly there is a charging port in the engine compartment but I was not able to find it and it wasn't described in the manual.

Got a new Prius in 2017, mainly because it has better safety features and convenience features than the old model did. (The Prius got a backup camera in 2006, the year after I bought one). In 2018 I moved. The new house needed some things so I took the truck and left the car at home. I had the truck for about 2 months while the car sat idle. When I was done with the truck I drove it back and picked up the car. After 2 idle months the car had no problem starting up.