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Charging Issues

Posted: Mon Jun 29, 2009 9:57 pm
by Fpv_83
Ey all

Ive got a problem in my fourby where the battery seems to be overcharging.

Ive got a national luna dual battery monitor and it sometimes beeps with the over voltage alarm which is sopposed to go off at 14.5V. Now with a voltimeter it reads 14.4, 14.5, sometimes flickers at 14.6V and i am wondering if there is something wrong with my battery. I have just had the alternator rebuilt fully and my battery is about 12 months old (not even).

Now this is what i did before it beeped at me, had the alternator rebuilt coz it sh*t itself and then all was fine charging at 14.2V. I drive my car once a week if im lucky and i thought the battery was gettin a bit flat so i chucked it on the wall charger for a couple of hours.

Now in the car when the engine is running it charges at like i said too high so the battery alarm doesnt like it.

Now have i damaged the battery or is it so charged up that the alternator doesnt need to charge it and is gettin too much voltage?

I really need it fixed and reliable coz i got a trip comin up in 2 weeks

Please Share any thoughts.

Cheers
Mark

Posted: Mon Jun 29, 2009 10:19 pm
by -Scott-
If anything, you have a voltage regulation problem, not a battery problem.

14.6V is on the high side, but it's not excessive if you have a battery in need of significant charge. If you have this voltage all the time, then there's an issue with the voltage sense line to your regulator, or the regulator itself.

If your alternator has an external regulator, that would be my first suspect. If it has an internal regulator, it would (should) have been checked during the rebuild. If it's an internal regulator, find the voltage sense line at the alternator and check the voltage on it.

Posted: Mon Jun 29, 2009 10:21 pm
by Fpv_83
yeh i charged it up on a 240V wall charger coz it was gettin a bit too low and only now it reads 14.4V-14.6V
Dont know whether the wall charge did anything 2 the battery?
Should i drain a bit of juice form her n then try?
Cheers Mate
Mark

Posted: Mon Jun 29, 2009 10:30 pm
by -Scott-
No, chemical-wise you can't have too much charge in a storage battery. Over-charging a battery literally cooks it - it boils off essential chemicals, and reduces the amount of energy it can store, not the voltage it can reach.

What is the battery voltage first thing in the morning, after the battery hasn't been charged or discharged for a long time?

Posted: Mon Jun 29, 2009 10:36 pm
by Fpv_83
dunno mate
was sittin at bout 12.6 this arvo after i took it for a spin and turned it off. try 2morrow morning and let ya know. what does the early morning voltage tell ya bout it?
Thanks mate
Mark

Posted: Mon Jun 29, 2009 11:19 pm
by -Scott-
The battery voltage can take a little while to "stabilise" after either charging or discharging (e.g. starting). First thing in the morning should give an accurate reading of the battery's true state of charge - and 12.6V is the magic figure for a healthy battery.

I was also wondering if your volt meter is accurate - sounds like it is.

Posted: Mon Jun 29, 2009 11:21 pm
by Fpv_83
yeh i think it is accurate
On my old mans cruiser it reads 14.2V steady
thought it might b out so i checked it on the cruiser and seems fine
Cheers mate
Mark