JDBO

Hey, I just joined the forum because i am restoring a 65 Coupe that I bought and had shipped down to were I live. They are such cool cars. I spent a day trying to start it and the battery went kinda flat from cranking over so much. The battery is a 600CCA duralast. The problem is I went to check on the battery charging and my voltage meter said the battery was at 20 volts, so I quickly unplugged it scared of an explosion. I read the battery without the charger and it is 18.8. What should I do is this normal? It had been charging at about 14v for three or four hours and then to go to 20 is freaking me out. It is an automatic 12v 6amp fast charger. Any help wuld be awesome! Glad to come to the light: Mustangs are BOSS

67mustang302

Are you sure it's a 12V battery? Many newer cars are starting to run 14, 16 or even 18V systems. Also make sure your voltmeter is reading correctly, check it on other batteries....even AA or AAA.

Starfury

To my knowledge, 14-18V automotive batteries are not readily available at parts stores yet. Commercial batteries are another matter, but those are usually much bigger, and I don't think autozone handles many of those.

In any case, to get a battery up to that kind of voltage, you have to supply that kind of voltage to it. I'd go get yourself another charger.

barnett468

shove it in the car and drive it.

try your tester in another battery to see if your tester might be inaccurate.

if its new, get a free replacement.

Derf00

Are you using a handheld voltage meter or the one built into the charger?

at 20v or even 18v a normal 12v auto battery would most likely swollen.

What is group size is the battery (I.D. 24, 24R, 24D, 56D, etc)? It will be on the battery tag.

I've never heard of cars using 14-18v systems...? Semi trucks sorta. They use 12volt batteries and it's normally not a single battery, rather it's 2-4 batteries set up in series / parallel or a combo of both to fit the electrical requirements of the rig.

67mustang302

Some newer high end cars are running higher voltage systems because of greater and greater electrical loads as more electronics are added.

Like Starfury said though, not sure if they're readily available, but it never hurts to double check.

I'd double check the voltmeter against a new battery, even a AA or whatever.

jonahdeich

Sounds like your voltmeter is bad. It is very rare for a 12v to get that high without serious problems. Goodluck on the car!

fastbackford351

You've gotta love those fixes. It's better to be safe than sorry because battery explosions are not fun.

67mustang302

Especially if your face is nearby when it happens..... =(