Battery loosing power

[alkers]

Hi all, hoping someone here might be able to help me out a bit. Basically I am getting a bit fed up of the garage. I went in with concerns that myvan was struggling to start when left for a few days or weeks (the taco needed fixing too, so mentioned this on the side). It always did start eventually, but took a few turns and revs. No jump required. Anyway paid them to "fix it", which they said the prob was the slave battery had a cell missing so was draining the main battery. So they just disconnected the two from each other (the slave was disconnected from the van aas we don't use lighting anyway, but still connected to the main battery).

Anyway,off I trot again with a fully charged battery. All packed to leave from w'end, but van wouldn't start at all. Turned key and no noise. However would jump start with a battery pack. But conked out again when I didn't accelerate. got to garage who kindly leant us a diesel battery for our trip. But obviously now it is back at garage again.

Now they are saying it is the alternator.

Now I am no mechanic, but I doknow that alternators and failing batteries go together (at least I think!), so am concerned that this wasn't checked first time round. What I can see happening is me forking out to replace this, only to find out the prob still continues and I have just spent 180quid on replacing a perfectly good bit. I can't keep shelling out on unknowns.

The starter motor was replaced in Feb09. And both my batteries are meant to be new as well. Along with MOT and full service in Feb 09 too. However, these weren't done by us as we bought in May, and no chance of returning to same garage.
Any thoughts!?!?! 1982 Aircooled Devon 1.9 petrol

[CovKid]

I had all kinds of issues on flat batteries and decided that the "not knowing whats going on" is the worst part. I'm using a split charge relay set up but it doesn't matter what set up you have, if theres a visual indicator for battery voltage both standing and when running, it takes a lot of the guesswork out of this and you can tell at a glance if your battery is losing power, if its being charged, and to some extent you should get some idea of whats causing the drain. Sometimes stereos will sap battery power (even when you're sure they're switched off) so I fitted a voltmeter (just £7 new) - see pic further down this page:

https://club8090.co.uk/forum/viewtopic.p ... r#p7380471" onclick="window.open(this.href);return false;

Easy to do, twin cable to whatever battery you want to watch (cheap flat speaker cable is great and runs under mats) or one wire and just earth the negative on the meter. You could fit two, one for each battery or just have a small double pole switch so you can view either battery on the one meter, up to you. It won't measure amps ofcourse but if your battery is slowly draining, the meter will show that at any given time. I find it very useful. After that its a case of finding whats still live and sapping your power. Hope that helps, or anyone else who wants to battery watch.

Just added this to WIKI under 'diagnosing' in electrics.

[kevtherev]

My 10 pence
May I respectfully suggest you get more familiar with your van and how it works.
I'm sure you can understand that a twenty five year old van is going to throw up a few problems from time to time.

The garage is quite correct in their approach to your problem, it was logical.
The engine gives up some of it's energy to re charge your battery, then maintain it's energy level after starting , via an alternator.

If your alternator does not do what it is supposed to do, then your engine will draw its power to run, from the battery.

diconecting the Auxilliary battery would take it out of the charging loop, concentrating your alternator power on the starting battery.
as the problem persisted, they then suspected the alternator as the fully charged battery lost its power on the way home.

a simple test that you could have done, would have saved you an inconvenient episode, and a feeling of being ripped off.
The more you know, the less you feel so vunerable.

[alkers]

Fair point Kevtherev. But in my defense I did think I had disconnected the leisure battery. However in my ignorance I had assumed that removing the connection from the leisure to the lighting was enough. I didn't realise there was a relay between the 2 batteries that continued to work. I thought that if the leisure had no use, then it wouldn't need to take any power.

I have been told by garage since however that this isn't the case. The relay is 2-way. So it was still taking.

So I take it you all think the alternator would be an obvious solution?

What are your thoughts on just reconditioning rather than a new one. Obviously half price to me!

[alkers]

PS am very keen to learn more about my van though, to do the basics, typical diagnosis, and servicing, including how to deal with rust!! So any local techy meets would be much appreciated!

[CovKid]

Just a thought here while you're at this stage, theres a 90amp alternator (think you'll find all this in the WIKI and elsewhere on the net) that you can scrounge from Golfs, Passats etc that is more or less identical to T25 alternator and only needs the pulleywhel swapping over. I did that some time ago. Theory is that with two batts, steroe etc etc, a 90amp alternator is no bad thing. Think mine cost £25 at most (ebay) and had no trouble with it so if you do replace, consider that option which is DIY to be honest.

The meter however would show you the rise in voltage as the alternator kicks in so still a worthwhile addition for peace of mind - again, cheap as chips.

[windysurfer]

Alkers, do you own a multimeter?

If not it would be money well spent getting one, then with help from people on here telling you where to stick the probes and whet to expect you can diagnose electrical problems yourself

[kevtherev]

as windy says you can check the out put of the alternator.
if the darn thing is producing less than 13volts... it's not going to help you charge batteries

What are your thoughts on just reconditioning rather than a new one. Obviously half price to me!

there could be too much wear on the carbon brushes in the regulator, if there is....

I would be removing the rectifier/regulator pack on the Alternator and renewing that at £15

or it could simply be a broken loose wire(s)

[littledave1980]

Invest in a voltmeter, think mine only cost about a tenner, it's basic, but does the job nicely.

Test the battery, just put the two probes on the battery terminals. With the engine off the meter should be reading 13+ volts, which means the battery is good. If the voltage gradually drops you have a drain somewhere. I had this problem and it turned out to be the stereo so rewired it to run just through my leisure battery.

Start the engine and test the battery again. With the engine running the meter should read 14+ volts which means the alternator is charging. If you switch on every thing that requires electricity, lights, wipers, heater fan, hazard lights etc the meter should still be reading 14+ volts. Any less than 14volts then you have problems with the alternator or related connections.

I fitted a 90 amp alternator from GSF which copes more effectively with the charging of 2 batteries while powering my stereo with amp and sub.

Hope this helps. Good luck with your issues.

[alkers]

Hi guys. Thanks for your help and for making me think the garage weren't ripping me off! anyway got alternator re-conditioned, 70amp, cost 70quid all in. Saved me a bit. It was faulty (so also good way of making sure the garage had spotted right problem - or at least one right problem).

Planning on re-connecting the leisure battery over the winter, and will do a complete check of the electrics in the caravan with help from my dad who's an electrician. Anyway whilst doing this I think I will get a voltmeter fitted, as I think that is a really good idea for peace of mind.

Cheers all

PS Techy meet near South London pls!!