Voltronic standby charger (3 Viewers)

[mick qc]

I fitted one of these to keep my starter battery topped up instead of Connecting up my 3 way victron mains charger to the starter battery after being advised not to.
I’ve turned my mains charger on to see if the Voltronic is doing what it’s supposed to but after an hour there’s no change to the starter battery readings, checked with my tester,
Any advise please, I’ve checked all the connections and all seems to be working,
I’ve got a 10mm cable from the starter bat to the Voltronic via a small bus bar.

 

[Jev88]

If your engine battery is full then it may not do anything.

 

[mick qc]

Cheers. Good point.
The first reading which I took straightaway was11.94 now it’s down to 11.86 after an hour

 

[mick qc]

I maybe should’ve took the starter battery reading before I turned on the mains charger and then took another reading when I unplugged the mains charger

 

[autorouter]

Check that the input voltage at the Votronic input terminal is the same as the leisure battery voltage. Check that the output voltage at Votronic output terminal is the same as the starter battery voltage.

The voltage of 11.94V at the starter battery shows that it is definitely not fully charged, so it should be taking a current of up to 3A.

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[mick qc]

Yes that’s what I don’t understand. All those readings are the same when I put a test on the leisure battery even after turning off the mains charger. The reading seems to go from 11.86 up to 11.92 and just keep fluctuating between those two readings.
I can only think it’s because the solar panels are giving it some charge even in these weather conditions but it never goes higher than 11.92
I have considered connecting my three way Victron mains charger to the vehicle battery as originally planned and doing away with the Voltronic

 

[autorouter]

What voltage do you get at the leisure battery terminals when the mains charger is on? It should be about 13.5V to 14.5V.

What voltage do you get at the Votronic input terminal when the mains charger is on? It should be the same as the leisure battery voltage, about 13.5V to 14.5V.

Remember that we can't see what you are doing, you have to spell out to us exactly what you did.

 

[headlight]

Yes that’s what I don’t understand. All those readings are the same when I put a test on the leisure battery even after turning off the mains charger. The reading seems to go from 11.86 up to 11.92 and just keep fluctuating between those two readings.
I can only think it’s because the solar panels are giving it some charge even in these weather conditions but it never goes higher than 11.92
I have considered connecting my three way Victron mains charger to the vehicle battery as originally planned and doing away with the Voltronic

If the battery was receiving charge from any source, including solar, it would show more voltage than you're measuring.
Below 12v is a quite depleted battery and lower than recommended for good battery health.

 

[mick qc]

What voltage do you get at the leisure battery terminals when the mains charger is on? It should be about 13.5V to 14.5V.

What voltage do you get at the Votronic input terminal when the mains charger is on? It should be the same as the leisure battery voltage, about 13.5V to 14.5V.

Remember that we can't see what you are doing, you have to spell out to us exactly what you did.

The voltronic came with a fused cable.
I’ve taken that out and now I’m getting better readings At the leisure battery I’m getting a reading of 14.1and the starter bat is now reading 12.9.
Hopefully it’s now working properly. Thanks for all the help

 

[autorouter]

The voltronic came with a fused cable.
I’ve taken that out and now I’m getting better readings At the leisure battery I’m getting a reading of 14.1and the starter bat is now reading 12.9.

That's more what I expect. You still haven't said what voltage you are getting at the other end of the leisure battery wire, at the Votronic input terminal. If there's a bad connection/oxidised fuse etc then there will be a voltage drop along the wire, enough to stop it working. If the two voltages are the same, and there's no voltage drop, then at least you know the wire is OK.

I don't know the details of how you are wiring it, but if you are wiring directly to the leisure battery it needs a fuse at the leisure battery end. A 5A fuse would be fine for this, the maximum amps expected through the Votronic unit is 3A. Maybe you could add in a fuse, it sounds like there was something wrong with the Votronics-supplied wire.

The same goes for the starter battery connection, if it's directly to the battery it needs a fuse, again 5A would be OK. Or maybe you are connecting to somewhere that's connected to the starter battery with a wire that's already fused.

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[mick qc]

That's more what I expect. You still haven't said what voltage you are getting at the other end of the leisure battery wire, at the Votronic input terminal. If there's a bad connection/oxidised fuse etc then there will be a voltage drop along the wire, enough to stop it working. If the two voltages are the same, and there's no voltage drop, then at least you know the wire is OK.

I don't know the details of how you are wiring it, but if you are wiring directly to the leisure battery it needs a fuse at the leisure battery end. A 5A fuse would be fine for this, the maximum amps expected through the Votronic unit is 3A. Maybe you could add in a fuse, it sounds like there was something wrong with the Votronics-supplied wire.

The same goes for the starter battery connection, if it's directly to the battery it needs a fuse, again 5A would be OK. Or maybe you are connecting to somewhere that's connected to the starter battery with a wire that's already fused.

At the voltronic input I’m getting the same reading as the leisure battery 12.9 now I’ve turned the mains charger off.
At the “starter “ terminal on the voltronic I’m getting the same as the starter battery.


I’ve got a 10mm cable from the starter battery to a small bus bar then from the bus bar I’ve got another length of cable, 2mm I think to the terminal on the voltronic named starter. I had to do it via a buzz bar as the 10 mil cable was too big to go into the Voltron terminal.
Like you said, this connection probably needs an in-line fuse.
I have a 2mm cable from the Voltron connection named bord to my 12v fuse box. This is fused at five amp.
Thanks again for all your help

 

[mick qc]

Now I’ve turned the main charger off my starter battery is reading 12.5