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How many volts should i get at the battery ?

Posted: 07 Apr 2007, 17:02
by Sven
Just tested the starting battery with the engine running with the mutimeter.
Looks like its charging at 12.80 volts...is this about right or does it seem a bit low? I'll have a look at the brushes on the alternator just to be sure.
With the van running on LPG and taking a few turn in the mornings the battery seems to loose its "power" relatively fast. Its only about 18 months old, the battery that is.
Thanks,...sven

Posted: 07 Apr 2007, 17:49
by eightball
should be showing about 14v normaly

Posted: 07 Apr 2007, 23:21
by vanjam
it's a boring old rote and a pain in the a***: but check, clean and secure ALL connections. I had a charging problem recently having just replaced a gearbox. All had been fine electrically beforehand. I went through all the starter and battery wiring, alternator output bench-tested, battery discharge test, searching for eart leakage faults and coldn't find a thing.

The very last thing I decided to look at was the earth strap from the gearbox to the chassis. When refitting the box, I'd dutifully cleaned the gearbox end of it and the flange on the box it connected to, added new clean washers and tightened it uo accordingly. I'd given no attention at all, other than a visual once-over and a quick pull, to the chassis end of the strap.

When, in desperation, I decided to have a look at this (as a last resort) I unscrewed the bolt which was only partially seized, cleaned everything up with a wire brush and refitted it: suddenly, no more charging problems.

Posted: 07 Apr 2007, 23:31
by HarryMann
.. and sometimes worth putting two on the gearbox if you've a spare braid hanging up doing nothing. Covers such eventualities.
Also can be worth earthing the alternator body directly to the engine firewall bulkhead with something pretty thick (like 65 Amp cable if a few feet lyinga round as well). This is especially useful on injection models(DJ) which can be sensitive to engine/chassis differential voltages.

Posted: 08 Apr 2007, 03:05
by Westy.Club.Joker
Buy a new regulator/brush pack, cost around a tenner for any Bosch alternator, they are all the same. Cheap to try and two screws and two mins to fit, worked on mine and cured the same problem you are having.

Posted: 08 Apr 2007, 08:49
by HarryMann
Think I remember charging voltage should be 13.8V...

AA carry those kits for many alternators, usually work a treat..

Posted: 08 Apr 2007, 12:57
by Sven
Thanks for the input guys...will get on with it
Cheers
Sven

Posted: 09 Apr 2007, 18:17
by Sven
Another quick question...what should a 240v charger charge to ?? Put the multi meter on the terminals while its been charging and its at 15v, this seem ok....its been on about 24 hours now.
Thanks again people
Sven

Posted: 10 Apr 2007, 00:29
by HarryMann
14.6 ~ 14.8 V probably for an unintelligent charger

Posted: 20 Apr 2007, 17:29
by vanjam
"unintelligent charger" - my bank perhaps?

Posted: 20 Apr 2007, 17:45
by R0B
sven after charging for 24hrs check voltage.leave it stood for another 24hrs. check voltage again.if you get a lower voltage the second time.the battery is not holding its charge.and needs replacing.

Posted: 20 Apr 2007, 17:48
by Dan Wood
...although a perfect battery will also drop a little bit, after being removed from the charger.

To be sure, take it off the charger and wait 24 hrs for battery to 'settle', then measure, then wait another 24 hours and check again.

Posted: 20 Apr 2007, 19:35
by HarryMann
"unintelligent charger" - my bank perhaps?

Hehe! That and obscene charger as well :)