Batteries or Alternator or something else

[Shadyadie]

Last week I had a flat battery and had to get a jump start, I took it to a garage who tested the batteries and said they were fine but the voltage from the alternator was poor. I have since took it to another workshop and the volts from the alternator now seem fine 13.6 - 13.8 on tick over.
No further problems till this morning when it wouldn't start, but hasn't been used for 2 days. ( had to leave jump leads on for a good few minutes as well)
Once started the alternator was kicking out 13.6 volts.

I have put it on a trickle charge for a few hours.

The alternator belt seems on the loose side, but I don't know how tense it should be? Is there an easy way to adjust, I have looked through threads and they all seem to deal with removal.

Could something be draining the battery when parked up? Have checked the lights.

Any help would be appreciated as we are supposed to be going away in it.

[Dobbslc]

try checking all the earth cable connections as this might cause voltages to vary. the belt should have about 1/2" of movement on the longest run.

[Shadyadie]

Thanks will have a look at the earth connection asap

[Shadyadie]

After trickle charging overnight I checked the car would start yesterday, but didn't use it.
This morning the batteries were flat again..

Jump started it and took it to a workshop were I disconnected both batteries and 1 held at 10 - 12 whilst the other was at 3 (when they were last checked by a mechanic he didn't disconnect anything)

Topped up the water on the dead battery and charged up, but the reading hasn't changed.

Can't get a 70 amp battery on Arran as nearly every where is closed for christmas and the places open only have a 60 amp

I have come up with an idea, will it do any harm to just run it on the one good battery until I can get a replacement?

[shokenore]

There is a reason your batteries are draining.

You need to fix this bit first or you will have to keep changing your batteries.
FYI last year over cold spell my truck was not started for over three weeks.
The batteries held their charge and the truck started.

A (new)60 amp battery in conjunction with a dubious one is asking for trouble.
What test equipment do you have?

If you have a test light or can make one then with the absence of a multimeter you can follow this guide
http://www.ehow.com/how_6073508_chec...drain-car.html

Or just disconnect the batteries when you have finished driving.

[Shadyadie]

Hi I checked the batteries with this thing with two prongs connected to a block and a dial on the top, No idea what it's called. (maybe a load test)

But when I mentioned to a mate that the garage had tested without disconnecting anything he said that was wrong and you need to test the batteries individually.

This done shows 1 is knackered and the other should be ok and I'm lead to believe a knackered battery can quite easily drain a good one to the point where there's not enough power left to start.

I can't get a battery till at least the 2nd if not the 3rd of Jan, but have disconnected the bad battery and am running with the "good" one. ( will show tomorrow morning if something else is also draining the power)
But will I do any harm just running the one battery until I can get a replacement? (providing the remaining battery is good)

[shokenore]

Have you checked for voltage drain from the batteries?
If you have a drain on the batteries it will not matter what amperage the battery is rated at if it receives no charge then it will discharge.

Finding a battery drain is not that hard to due, have you followed the easy guide posted above?
Is the alternator belt loose?

Running on one battery is possible however the diesel lump assuming it is a diesel you are running will require quite a bit of energy to turn the engine over.
The colder it gets the more it will take to crank over, and assuming you are only doing short journeys sub 20 minutes then you are probably not returning the battery to full capacity which will then make the next cold start even more of a drain till it reaches the point that it will not crank over.

IMHO I would check the alternator belt is correctly tensioned if not get it sorted.
I would then check to see if there was a voltage leak with the ignition off that is causing the drain in the first place and get that sorted.
I would factor in the journeys I need to do between now and when you can get the proper batteries and probably just keep on jump starting it.

[Overland Tonka]

A timely thread...I went through all this advice today as I was having similar problems.

Ended up that my red optima was duff. The yellow one is fine, so I went out and coughed up for a bosch silver top 780cca...spins up a treat now.. Thanks.

[Dobbslc]

If you take out one battery make sure you tape up the leads so they don't short out! .....

It is possible that a duff battery can self discharge and because it's connected to the other that will go flat too.
However if you have a current drain somewhere or a knackered alternator
you will be back to square one with a flat battery.

[Shadyadie]

If you take out one battery make sure you tape up the leads so they don't short out! .....

It is possible that a duff battery can self discharge and because it's connected to the other that will go flat too.
However if you have a current drain somewhere or a knackered alternator
you will be back to square one with a flat battery.

Thanks,

I have isolated and sorted the leads

I haven't used the surf today and will test it out tomorrow, If there is a current drain somewhere it shouldn't start if it's true to form (hoping it does start cause then I've got the problem)
biggest worry is going on the ferry Wednesday I don't want to have problems whilst people are waiting to get off, but have borrowed a boost pack just in case.
Looking at getting a Bosch S4 069 from europart once on the mainland.

[Shadyadie]

Update

Left for 2 days on one battery and it started fine,
Kept to very short journeys until Wednesday when I collected a new bosch battery, they even let me leave my knackered one, then drove to Edinburgh where the car sat till sunday (used buses as it was easier and cheaper as the car park was £15 every time you went out)

Came to start on Sunday and it fired up first time ( after 4 days standing), looks like it was the duff battery.

Thanks for all your help