charging question

[suggs]

am i correct in that if im getting about 12.9-13v at the battery with the engine running, and if i disconect the alternator and the volts drop to 12v at the battery then everything is charging correctly?

as ive just had a flat battery and its only a few weeks old, shortly after fitting a new battery the alternator belt snapped and battery whent flat driving home, after i replaced the belt i jump started the 90 and drove about 20 miles, since then ive only done a quick local trip when it started but didnt fell like it had a full punch to it. its since been parked up for a week in the cold weather and today it was flat as a pancake. it jumped started straight up and then i used a multi meter to get the above results, im just trying to find out if its the alternator, battery or if it just wasnt fully charged and the cold has knocked it out.

ive now got it on charge..

cheers

[muddysteve]

14.2v is what your looking for

maybe your alternator is on its way out

[suggs]

yeah maybe :?

seems to be rising now as the battery is charging, getting 13.7 when ticking over, have to see what it shows once fully chraged

[V8MoneyPit]

If it drains down while you aren't using the vehicle, it's either a faulty battery or a dead short somewhere.

Stick it back in once it's fully charged. Check the voltage then leave it for a couple of days. If it's drained down, you know it's not a charging fault.

[suggs]

yeah thats what ill do, worth while getting an on board volt meter to keep an eye on these things :idea:

would a 20 mile drive be enough to charge a flat battery?, bit of luck it wasnt and the cold weather just took it down..

[Guardian.]

ive just bought a new batery, so big its gotto go in the back, i suggest you also get a new battery, the first few cold mornings soon sort the men from the boys!, and kill of the weak.

[suggs]

it is a new heavy duty battery, only had it for a month or so...

[Muddy]

Landrover voltmeters arnt worth the dash space your much better off with a good multimeter, with a reasonable amount of revs you should be seeing 14.4 volts accross the terminals and about 12.5 when the engine is off.

Check and re check your earth straps as these can cause hi resistance giving the symptoms of a flat battery.

If you do buy a new battery i wouldnt waste my money on a gel foam spacecraft pintofmilkaday jobbie get down your nearest tractor place and buy a good sized battery that nearly fills the seatbox.

[L90OOK]

If our alternator is on it's way out it is possible the diodes are shot meaning the battery is able to drain back through the alternator.  Try disconnecting next time you have used it & attach next time you want to use it.
The Alternator should be putting 14.4v into battery.