Truma SDC12 Solar Controller

[Graham U55]

I have the above fitted to my Challenger and it has worked fine since I installed it in September 2023. It kept the battery topped up in storage. I went away a couple of weeks ago and there was plenty sunshine for long hours but the solar wasn't kicking in. I was on ECU. It remained at the state 'MPP' which means ready to charge. The second week I wen to another site and had ECU. This time is did move into charging mode and the Swift Command display showed it was charging. Moving back to storage last weekend the battery is staying at 12.7 and it normally varies from that to 13.4v.
I think it is in warranty but I wanted to know if anyone has any idea what could be wrong. The battery is also less than 2 years old.

 

[ProfJohnL]

My initial thoughts is you may a poor connection to the panel, but I suspect you have already checked that. But have you checked the panel for damage or is it in the shade? Even partial shade can have a disproportionate affect on a panels output.

In terms of warranty, this can get messy as you tell us you fitted it yourself so neither the caravan seller or Truma are likely to be prepared to look at the system free of charge, but if a component is found to be faulty the component cost should be covered. Do read all the warranty documentation to understand what is and what isn't covered.

 

[birdman101]

Sounds like a poor connection .There is a yellow 20 amp fuse on the controller pull this out and give it a wriggle when replacing it, to make a good contact. Also with the mains switched off remove the cover of the Sargent consumer unit,and you will find another Yellow 20amp fuse for the Solar charging do the same again with that removing it and a good wriggle pushing it back in.

 

[Graham U55]

My initial thoughts is you may a poor connection to the panel, but I suspect you have already checked that. But have you checked the panel for damage or is it in the shade? Even partial shade can have a disproportionate affect on a panels output.

In terms of warranty, this can get messy as you tell us you fitted it yourself so neither the caravan seller or Truma are likely to be prepared to look at the system free of charge, but if a component is found to be faulty the component cost should be covered. Do read all the warranty documentation to understand what is and what isn't covered.

Thanks for the response. I have checked connections but will recheck them. I spoke to Truma and because the install was working since September 2023 they are happy with that. I had no ladders at the storage when I was there to speak with them but will check again weekend. I am grateful for your help.

 

[Graham U55]

Sounds like a poor connection .There is a yellow 20 amp fuse on the controller pull this out and give it a wriggle when replacing it, to make a good contact. Also with the mains switched off remove the cover of the Sargent consumer unit,and you will find another Yellow 20amp fuse for the Solar charging do the same again with that removing it and a good wriggle pushing it back in.

This is useful, I will check both fuses. I will check both.

 

[JTQ]

It hopefully should only charge if the battery needs to be charged; my Morningstar branded ones have simply chopped the charging amps to zero when the batteries involved are charged.

I would forget measuring volts, and measure the amps it charges with.
One of these fuse based current testers are ideal, and can even be a permanent fit, just switch on to check current value. LINK

 

[Graham U55]

It hopefully should only charge if the battery needs to be charged; my Morningstar branded ones have simply chopped the charging amps to zero when the batteries involved are charged.

I would forget measuring volts, and measure the amps it charges with.
One of these fuse based current testers are ideal, and can even be a permanent fit, just switch on to check current value. LINK

Thanks for the input and advice. Much appreciated. You reminded me i have one of those devices

 

[birdman101]

The same controller is in our caravan and on mains hook up today , nice sunny day and as usual when full sun all 3 Green LED lights on.

 

[Graham U55]

The same controller is in our caravan and on mains hook up today , nice sunny day and as usual when full sun all 3 Green LED lights on.

That’s exactly what was happening until two weeks ago. Now only the MPP light flashes slowly. I think it’s a faulty unit and will put the old one back and see what happens with that. Thanks for the reply