Battery discharge

[Fin]

Maybe an interior light or something that shouldn't be connected - is it possible to trace the wires?

[Ralf85]

12.35v showing this evening after yesterday's run (40 miles). I think I will take the battery out tomorrow and put it on charge to see what that does. What should the voltage be on full charge? If it does not charge up fully then I will buy a new one. Cheers

[ghost123uk]

After an overnight charge and then a rest for at least 4 hours it should be close to 12.9 volts.

[Ralf85]

After an overnight charge and then a rest for at least 4 hours it should be close to 12.9 volts.

Cheers for that. I'll whip the battery out later and charge overnight and see what happens.

[RobH]

Possibly a dumb question, but have you measured the battery when it's "flat" and what's the charge then?

Just wondering what your symptoms of the flat battery are.

[Ralf85]

11.81V and the starter tries but cannot turn the engine over. Up to 12.3V and wizzo it stars without a problem. The battery is on charge now so I will check tomorrow to see if I can get it up to the 12.9V recommended by Ghost123.

[itchyfeet]

11.81 is very flat.

[Ralf85]

After an overnight charge and then a rest for at least 4 hours it should be close to 12.9 volts.

The battery was on charge for about 14 hours overnight. Switched charger off 4.5 hours ago. Battery now showing 12.9 volts. So if the battery is ok and I drive the van more the problem should be solved, hopefully.

And thank you again guys for providing a real education about how batteries function. I'm sure a lot of people have learnt a lot through following your advice.

[ghost123uk]

Sounds good, let us know how it goes

[itchyfeet]

good excuse to use the van more

[Ralf85]

Hi guys

48 hours later and the main battery is now showing 12.65 volts. So that is quite a drop from 12.9 volts in such a short space of time. As you guys have already said this is much more than the 0.11 amp drain I recorded earlier this week.

In a westie system would the state of the leisure battery have any impact on the main battery or are they not connected at all? The only reason I ask is that the leisure battery is just about due for replacement (although it shows up in the green fully charged scale on the stove unit).

[AdrianC]

In a westie system would the state of the leisure battery have any impact on the main battery or are they not connected at all?

Unless the split charge relay's stuck, or somebody's done something silly when they've added a different charger, then they're only connected when the alternator's charging.

[itchyfeet]

look at the voltage table in this post.
https://club8090.co.uk/forum/viewtopic.php?f=39&t=115856" onclick="window.open(this.href);return false;

12.65 is fully charged,keep watching it and see what happens in the next 48 hours.

[Ralf85]

Right guys an update. I have put a new starter battery in the van. The one it replaces was a newish one (a year old) and I charged it up and it has held it's charge for a week now. I used this to replace my leisure battery (proper leisure batteries don't fit). So with two fully charged batteries in place the voltage regulator should now keep them both topped up. Thanks again guys for explaining about the electrical charging process. That helped to de-mystify the topic for me. Cheers!

Almost forgot, when I got to the leisure battery ( a pain - having to take the seat out - compared to the starter battery which is easy) for the first time since I replaced it over four years ago, I found old style flat connectors on the old battery - doh! Onto Amazon and got some new normal round connectors for £3. Fixed.