Battery Problems

ched999uk said:

If the battery and alternator has been tested by a reputable company then you might have a parasitic load on van battery. i.e. something is pulling power when the key is out of the ignition. I once had a vectra that had a broken vent flap motor. sensor It would try and close the flap and as the sensor was faulty it would keep powering the motor. Over a weekend it would flatten the battery. You need to get a multimeter on the battery to see what current is being pulled then isolate 1 circuit at a time to find what may be causing it.

Then again if Both batteries are going flat that maybe suggests something else. If the split charge relay is stuck in the on position it can cause the 'leisure' battery to pull charge from the van battery. Did they test the leisure battery? You need to test the voltage either side of the split charge relay when engine is running and when stopped. It should only connect the leisure battery when the van battery is in a good state of charge.

Hope that gives you some ideas?

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CollingwoodCleaning said:

Hi all,

Long time reader, first time poster here on the window cleaning forums.

With winter approaching I've started having some issues with my vans batteries (engine battery and leisure pump battery) and I was wondering if anyone had had similar issues/knows a fix?

So I have a van which I brought of a friend with all the kit fitted, including a battery with a split charge relay connected to the engine battery. Recently my engine battery has been going flat alot, especially during a day when I'm working in one area and/or been working on one job for a long time. However after having it tested I've been told that battery is fine. Then the alternator was tested, that was fine as well. I thought maybe the leisure battery is dying, which might be draining the engine battery. Nope, leisure battery tested fine too (which I thought might be the case as I bought it only last winter). 

What I'm wondering now is that because the batteries are connected via split charge relay, when the pump battery gets low due to alot of working in one area and not alot of driving, if that's starting to drain the engine battery. Can that happen? And If that is the case does anyone know a fix? Maybe a component I can insert somewhere on the wiring? 

Your help would be much appreciated, it's a right pain having to call the wife to ask her to bring the car for a jump start when I'm on a job. ?

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CollingwoodCleaning said:

Ah ok, will get round to looking at then this weekend, got some other work to do in the van so will dust off the old multimeter.

they did test the leisure battery, that was putting out the exact voltage of the starter battery. Thats what was making me thing they're piggy backing off each other in some way. I'll double check that though, when I get the multimeter out. 

Thanks for the tips!

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spruce said:

Did you come to any conclusions?

When I read this I wondered which split charge relay you had installed. There are 2 types; a standard split charge relay (SCR) and a volt sensing relay (VSR).

The standard relay has a trigger wire that is connected to a power source to activate the relay. Its usually either put on the alternator post that triggers the alternator charging warning light or the ignition accessories position. If its connected to the accessory position on the ignition key switch this means the relay isn't connected when the engine is switched off and when it is being started. But it will activate the relay when the accessory position is active, either with the engine running or not.

A VSR will only connect the 2 batteries when the alternator has topped up the starter battery first.

Now here's the point. They can test a starter battery by fully charging it and then putting a load on it of a known current draw and watch how the battery responds.

A simple test on an alternator to see if its charging is a volt meter. If it reads 13.9 volts or above then they says the alternator is good. I have seen an alternator giving the correct output voltage but very little amp output.

How did they test the leisure battery? You can't use the same method as a starter battery.

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CollingwoodCleaning said:

So, I haven't been able to test the readings with the multimeter this weekend, was applying some truck bed liner to van which was a long overdue job. However, I definitely need to have a look asap as I've needed a jump twice this week, once Monday morning as it wasn't driven all weekend, and once today as I had a big gutters and conservatory roof job at one property all day. I kind of expected it on Monday morning, but was abit cheesed today as I gave the van a good drive out on Monday evening. 

They did test the leisure battery using the same tester they used for the starter battery. The clip on standard sort of testers they would use at a autoshop. 

Will give it a test myself on Friday and will report my findings on here.

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