Am I overcharging?

qwertyd10n · Post by **qwertyd10n** » October 4, 2009, 11:51 pm

Hey guys,

Got my new voltmeter in this weekend and noticed it seemed to be reading a little high. So, I pulled out my handheld voltmeter and checked the voltage at the battery. When the truck is off, the voltage read about 12.9. When the truck is running at a warm idle, it read between 15 and 15.25.

Do I need a new voltage regulator?

Cheers,
Dion

64fordf100292v8 · Post by **64fordf100292v8** » October 5, 2009, 12:14 am

That sounds a little high. Ive had lots of alternators charge that high on a real cold morning start but they would only do it for 30-45 seconds then taper off to around 14.5. Are you running a alternator or a generator?

Uncle Skip · Post by **Uncle Skip** » October 5, 2009, 9:55 am

You need to keep an eye on the battery water and make sure you're not boiling it dry. If you're not having a problem there, you're good to go. Most alternators put out in the 14.5+ volt range so you're pretty close.
Just watch the water level
U@ss

qwertyd10n · Post by **qwertyd10n** » October 5, 2009, 10:05 am

64fordf100292v8 wrote:That sounds a little high. Ive had lots of alternators charge that high on a real cold morning start but they would only do it for 30-45 seconds then taper off to around 14.5. Are you running a alternator or a generator?

I'm not entirely sure... I'm guessing an alternator, but how do I know for sure?

Tech · Post by **Tech** » October 5, 2009, 10:47 am

What type battery do you have?
If it is a deep cycle, big truck battery or heavy for its size then yes you are probably boiling it.
If it is an Interstate of seems light for its size it will have a stronger acid strength and be able to utilize the higher voltage without a problem.
Are the terminals perpetually corroded? This might indicate outgassing/boiling. The battery may also get hot after a long run.
If you don't have any of the above symptoms then you just have brighter headlights!
What does the voltage go up to if you rev up the engine?
Small cars and motorcycles run higher voltages but old trucks?? It is probably just shortening your battery life a few years.
Tech

ICEMAN6166 · Post by **ICEMAN6166** » October 5, 2009, 10:53 am

you have an alternator. last year for generators was 64.

i dont think 15.25 is too high, 16v or more would definitely be an issue.