[benoflondon]

I've been getting a strained response when starting the van after it has been left for a few days - it starts - but it hasn't got a lot of power to start with, you can tell its struggling.

I found a thread that said that I should get around 14v when the engine is running and i think around 12-13v when the engine is off.

I connected the test meter to the battery terminals and with the engine off I got 10.5v - clearly not good enough and sure enough, when i turned it over, it struggled. Once the engine was running though the meter hovered around 13.78 - 13.85 volts and with the revs up it crept into the 13.9's and even hit 14 v momentarily but nothing higher.

In the other thread the guy was getting 14.2+ volts
Also, when i got the van 3 months ago, the guy said it had had a new battery, and it looks fairly new so I'm inclined to believe that the battery may well have been replaced but that it is not the issue.

Is there anyone around right now that has any idea if this 13.8ish reading is indicative of an alternator issue or is it doing its job good enough?

 

[Rustybus]

Battery is duff!!!!! Alternator is compensating

 

[Luck Dave]

as ^ says you battery is past its best.

 

[benoflondon]

Great. you sound pretty confident so that's where I'll spend the money.
Thanks, It's good news considering the alternative... (pun intended, sorry)..
I'm always keen to learn though can you tell me what you mean by "the alternator is compensating"and what should the voltage be when i put a new battery in?

Thanks in advance, your attentive student, Ben.:ILU:

 

[Rustybus]

can you tell me what you mean by "the alternator is compensating"and what should the voltage be when i put a new battery in?

Thanks in advance, your attentive student, Ben.:ILU:

When a battery is below normal voltage (yours was 10V) The alternator is trying to get it back up to 12v (which is the approximate voltage that the alternator excites (starts charging)) it therefore has to compensate for the voltage being too low, so will overcharge as soon as the alternator turns. I hope this does not confuse you T:

 

[JIMMYJAMES]

You learn something every day, i love this place T: