VSR problem, guidance please.

[Dan Tribe]

At the end of a long summer cruise my voltage sensitive relay seems to have died.
My set up is, 85 amp starter battery and a bank of 3 x 110 amp domestics fed by a vsr.
This has bèen fine until the penaltimate day when I noticed that the domestics were a bit low at 11.9v depite a few hours motoring, so I connected the charger in Ramsgate overnight. In morning the charger seems to be kaput and no charge to domestics with engine running.
1/ can the dead vsr have killed the charger or vice versa?
2/ can the vsr be checked or should I just replace?
I have temporarily bypassed the vsr but am now paranoid about losing engine start ability.

 

[Champagne Murphy]

Is the start battery ok.? What voltage does it have?
I've never heard of a vsr going like that, are you sure that all the connections are good? I've just had a problem with my starter motor which declined to work on a whim of its own. After testing every damn piece of wire I could find I had to resort to cleaning all the terminals before it would work again.

 

[BabaYaga]

At the end of a long summer cruise my voltage sensitive relay seems to have died.
My set up is, 85 amp starter battery and a bank of 3 x 110 amp domestics fed by a vsr.
This has bèen fine until the penaltimate day when I noticed that the domestics were a bit low at 11.9v depite a few hours motoring, so I connected the charger in Ramsgate overnight. In morning the charger seems to be kaput and no charge to domestics with engine running.
1/ can the dead vsr have killed the charger or vice versa?
2/ can the vsr be checked or should I just replace?
I have temporarily bypassed the vsr but am now paranoid about losing engine start ability.

It is not clear to me how your mains charger is connected, but presumably directly to the domestic bank. If so, hard to see why it should have been effected by a non functioning (open) VSR.
Perhaps one of the domestic batteries is on its way out, internal short etc?
I imagine it should be fairly easy to check the VSR with a multi-meter.

 

[Dan Tribe]

It is not clear to me how your mains charger is connected, but presumably directly to the domestic bank. If so, hard to see why it should have been effected by a non functioning (open) VSR.
Perhaps one of the domestic batteries is on its way out, internal short etc?
I imagine it should be fairly easy to check the VSR with a multi-meter.

The charger is just a basic 6 amp car battery charger from Argos, connected when needed to the domestic bank with crocodile clips. Very low tech I know but has worked well enough all summer. The batteries are usually kept topped up with a small solar panel and motoring.
We had come from Nieuwpoort to Ramsgate and used the engine for about 4 hours so I expected the batteries to be well charged. I connected the charger in Ramsgate and the lights came on but in the morning it had stopped working and domestic batteries down to 11.8 v.
Started engine and starter battery showed 13.2v but nothing going to domestics. As a temporary fix I bypassed the VSR and all batteries now being charged but of course the start battery is not independant any more.
I have disconnected and checked each battery separately and all show the same voltage so I assume not a faulty cell?
Probably the VSR fault caused the batteries to get so low that the little charger couldn't cope.
Now I'm home I will double check all connections especially the sensor wires.

 

[BabaYaga]

You don't say much about the loads on the domestic batteries, but if these are moderate the voltages mentioned seem very low to me.
Also I do not think you can expect a 330 AH bank to be well charged after only four hours of motoring.
In addition, 13.2V on the starter battery when the engine is running seems low as well. I would have assumed this battery to be almost fully charged already and a voltage at around 14.4V or so.

 

[VicS]

The charger is just a basic 6 amp car battery charger from Argos, connected when needed to the domestic bank with crocodile clips. Very low tech I know but has worked well enough all summer. The batteries are usually kept topped up with a small solar panel and motoring.
We had come from Nieuwpoort to Ramsgate and used the engine for about 4 hours so I expected the batteries to be well charged. I connected the charger in Ramsgate and the lights came on but in the morning it had stopped working and domestic batteries down to 11.8 v.
Started engine and starter battery showed 13.2v but nothing going to domestics. As a temporary fix I bypassed the VSR and all batteries now being charged but of course the start battery is not independant any more.
I have disconnected and checked each battery separately and all show the same voltage so I assume not a faulty cell?
Probably the VSR fault caused the batteries to get so low that the little charger couldn't cope.
Now I'm home I will double check all connections especially the sensor wires.

13.2volt is very low. The vsr may not close at this voltage

 

[dk]

Very likely a duff starter battery if it doesn't get above 13.2V. Most VSRs don't cut in until the engine battery reaches 13.8V.

 

[Champagne Murphy]

How much had you been using the charger before you found the problem? It may be that if the charger had failed the vsr was protecting the start battery and the domestic set wasn't getting charged. You wouldn't notice until the voltage drop stopped things working. I had two chargers fail on a summer cruise, one a ctek and one sterling so it's not that odd and far more likey than the vsr

 

[BabaYaga]

Very likely a duff starter battery if it doesn't get above 13.2V. Most VSRs don't cut in until the engine battery reaches 13.8V.

The OP has bypassed the VSR and all batteries now take charge and show the same voltage. So one duff battery seems unlikely to me.
I begin to wonder if the alternator puts out as it should. Blown rectifier diode, perhaps?

 

[DanTribe]

I may have mis-remembered the actual voltage figures. It was 7.30 am in Ramsgate with a wet & windy passage to Burnham in prospect.
I was just relieved that all batteries were now receiving a charge and I wouldn't be left without navigation electronics mid estuary.
Now back in Burnham I have the batteries on charge and will check all connections and re-test.