A couple of solar questions

[Nixdorfer]

Our 2007 Autocruise Stardream has a Sargeant control panel and 90w solar on the roof. The Sargeant controls the charge, I assume by PWM

I store the MH inside at work so end up moving it most days so we can use the workshop.
Having read some of the solar panel/charger discussions on here I wonder if fitting a better controller (mppt) to eek a bit more out of the humble setup we have would be worthwhile. Also as its moved regularly the battery needs charging every so often as doesn't get run long enough

If we had a better controller that did twin batteries it would be dual benefit as the batteries will get a bit of charge during the day and reduce how often I have to put it on hookup. Also when we do get to use the MH a more efficient setup is never a bad idea

Seen the Victron MPPT 75/15 but only seems to do one battery, or maybe spend more and look at the Voltron 250 one that does twin batteries and futureproofs us if we add more solar. But thats unlikely for now

Our current setup only charges when the panel is turned on, then when I move the MH it turns it all off.

Can the others be left on full time to maintain things?

Any of it sound reasonable or a waste of time and money?

 

[pappajohn]

At this time of year its lack of sun and too small panel.
Here, yesterday the sun appeared, first time for nearly two weeks.

 

[funflair]

Yes a better controller would look after two batteries, also a MPPT would get a bit more power from the panel that you have but another one would be a good idea, and you get a bit of charge into your starter battery is with a battery master.

You mention a Voltron should that read Votronic ? which are good

More panels would be good though whatever you do, I am puzzled by the switching off comment ! are you saying that the solar does not charge when the panel is off ?

Martin

 

[Nixdorfer]

Thanks for replies

As far as I know it doesn't charge. Need to get a meter on there to check, but as the panel that controls everything else turns off when I move the van I took it that also went off.

Could well be Votronic, seen others rave about them on here and forgot the name

More panels is something we could look at later as there is space. Sadly we aren't getting much use out if this year so until we start using it more we can't even tell how it copes as is. Just improving what we have would be a start and if I put a better controller on then half the job is done I thought

Heard of the battery master, if you had a twin solar charger would that not do a similar thing?
Will have to price up if a Victron and battery master costs as much as a Votronic, and which would be better

 

[funflair]

Bang for Buck to start with would be another panel if your existing controller can handle two, if you change controller to MPPT (Votronic MPP) make sure it is big enough to upgrade the panels later and yes a duo controller will charge the starter battery a bit but only when the sun is on the panel, Battery Master is different to duo controller in that it takes some power from the habitation batteries to top up the starter battery so it will do this even without any sun but it does of course mean that you need to charge the habitation batteries somehow.

Martin

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[Nixdorfer]

Thanks, from what I recall reading the handbook when we got the motorhome (nerd alert) I think the control panel can only handle 100w solar anyway so would need a better controller before we did any other upgrades. Will weigh up which way to go. If I have to replace the controller regardless then may as well consider that as a first job then look at panels. Making sure the controller has enough capacity for panel upgrades

 

[autorouter]

I think the control panel can only handle 100w solar anyway so would need a better controller before we did any other upgrades.

I think it's quite normal to have more panel wattage than the controller specification. Especially in Northern Europe where the days can be shorter and the sun is lower in the sky. The solar controller just wastes any excess power, You get the benefit in that it gets up to speed sooner, and drops off later in the day.

 

[Leakylunar]

Sargent have a harness that enables that connects from solar controller to the Sargent unit so both batteries are charged assuming gab battery has priority. I’ve purchased one but still to buy solar panel and controller as my Sargent ec325 is restricted to 100w.

 

[two]

Whilst MPPT may be better than PMW, it's only by a small margin.
You can get your solar controller to charge both batteries by adding a BatteryMaster (or similar), so don't have to discard the existing controller.
100% more of next to nothing is still next to nothing. Solar is best further South and in Summer. What you harvest in the UK, in Winter, will not be a lot.
To get more power, you'll need another panel. You could add an additional small controller, if the present one cannot cope, and gain resilience.