1999 V70 Only charging at 13 volts Alternator or Regulator?

PapaHepcat · Post by **PapaHepcat** » 04 Jan 2015, 20:13

So the battery my '99 V70 xc sometimes struggles to start the car. I had the charging system checked at my local Napa store, and the guy said that the battery was showing 12 volts, and was fine (I know there's a .2 or something also, but I don't remember what that was). When I started it, though, he said the voltage dropped way down and slowly built back up until it settled on a little over 13.

I've searched a bit, but didn't find any threads that quite like this, and I didn't want to hijack a thread. Please point me in the right direction if I missed something.

So from your experience, would you say it's the alternator? Or maybe regulator on the back of it? I still need to verify that my car has that setup. And how difficult is it to pull and replace the alternator? There didn't seem to be much room to work with in there.

Post by **Ozark Lee** » 04 Jan 2015, 20:27

I'm a bit surprised that the NAPA guy didn't load test the alternator. Most auto parts stores have a nifty analyzer that determines alternator current output as well as voltage. All of which is done with the alternator installed in the car.

13.5 - 14.5 volts is a typical alternator output but that can sag under load which is why they load test the system. I'm fairly sure that most Autozone stores have the proper system analyzer and I know that my local O'Reilly Auto parts store does. Advance Auto Parts should have one as well.

What you describe sounds more like a weak battery than an alternator problem but the proper test should tell you.

...Lee

PapaHepcat · Post by **PapaHepcat** » 04 Jan 2015, 20:42

Yeah, he just had this handheld thing. I thought I saw a switch that said "Load" on it, but he only flipped it for a moment, and not when the car was running. Maybe I'll try again at Autozone or wherever. See if they'll roll out the big machine.

I sure hope it's the battery. Easier and cheaper! And the battery is an OEM Volvo one. Maybe original, even.

Herb Goltz · Post by **Herb Goltz** » 04 Jan 2015, 20:56

Have the battery load tested too while you're at it-- measuring resting voltage doesn't tell the whole story. With a $10 multimeter you can check the alternator output and measure voltage drops caused by increased resistance in the battery cables. Compare voltage at the alternator and at the positive battery terminal. Is the positive or negative cable hot to the touch when the car is running?

PapaHepcat · Post by **PapaHepcat** » 19 Jan 2015, 22:51

I ended up taking the poor car to like 3 or 4 other places - I kinda lost count after a while. They all used similar handheld things. Argh! In the end, Walmart of all places finally pulled it in to test using one of the "big machines." Battery was bad. One of the cells was shot. They checked the alternator/regulator, which was fine. Whew!

And I got a great price on some groceries while I was at it.

IslandV70 · Post by **IslandV70** » 12 Mar 2019, 08:25

Any voltage under 13.8 will charge the battery VERY slowly and not to 100% either. Some advanced charging systems will back off to 13.5 (+ or - ) to be easy on the battery after it is full. My car seems to vary between 13.8 and 14.4.

Post by **abscate** » 12 Mar 2019, 21:16

Op bought so many groceries he hasn’t been back since..