Upgrading solar (1 Viewer)

[Romolo]

Hi peeps

I am having some work done on my campervan.

I was thinking I might upgrade my existing 120watt (calculated) solar panel and 20amp charger. Or just solar panels. And try and get 300watt or more as I am removing existing solar to do some roof work.

Any thoughts if I can keep existing solar charger and if cables would need an upgrade for that kind of increase?

If I do it.. it would make sense to do it now as the solar is coming off just unsure what is compatible and what I need to do in etween.

Also putting a second leisure battery so there will be more to charge..

Thank you in advance

R

 

[Romolo]

Current solar panel reads at 5volts regularly when I check.

Thanks

 

[Romolo]

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[Lenny HB]

Your exsisting Solar controller is only PWM type and it's not a multistage charger, by fitting a decent Solar MPPT controller like a Votroinc or Victron you will get up to 30% more output.

 

[autorouter]

The existing controller will be OK for up to twice the solar panel watts (250W), but any higher and it would be better to upgrade it. A 30A MPPT type for example. MPPTs can take a higher voltage, so if you also go for a bigger panel, you can consider '24V' panel, so the voltage will be higher (36V instead of 20V). That means the panel current will be less, so you can keep the existing wiring though to the roof. Probably worth beefing up the wiring from controller to battery, but that's probably easier.

 

[Raul]

View attachment 533479
View attachment 533480

I can see 4,2A coming in from the solar. Are you sure you measure correct the panel? Or this is a old picture when it was working.

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[autorouter]

Current solar panel reads at 5volts regularly when I check.

Do you mean 5amps? That's a possible normal value. 5volts from the panel looks like a bad fault somewhere.

 

[Romolo]

Sorry yes 5 amps

 

[Romolo]

These are pictures today... But battery is topped up

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[Raul]

Then your panel is working fine, and 4,2A at 14v the battery is not that full. It’s just hit the absorb stage, long way to full.

 

[Romolo]

Well the van lives outside my house and is not used for weeks.... So battery should be full most of the time. There is no load on when not in the van.

The solar was 0 ampage. ... Then I turned some lights on to get a reading.. so I got 4.2amps.

Battery should be full all the time. Even driving around today it was used to transport no leisure battery in use.

Thanks

R

 

[Romolo]

The existing controller will be OK for up to twice the solar panel watts (250W), but any higher and it would be better to upgrade it. A 30A MPPT type for example. MPPTs can take a higher voltage, so if you also go for a bigger panel, you can consider '24V' panel, so the voltage will be higher (36V instead of 20V). That means the panel current will be less, so you can keep the existing wiring though to the roof. Probably worth beefing up the wiring from controller to battery, but that's probably easier.

Thanks... This system says it is 12v or 24v... I have a 12v fridge etc... But if I beef this up as you say would I need to upgrade everything? I am happy to replace with bigger single panel... Any recommendations? Many thanks

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[autorouter]

Thanks... This system says it is 12v or 24v... I have a 12v fridge etc... But if I beef this up as you say would I need to upgrade everything? I am happy to replace with bigger single panel... Any recommendations? Many thanks

It can get a bit confusing I think. I'm sure your habitation battery and all the devices are '12V', like most motorhomes. That stays the same, no problem.

The smaller panels have a voltage of 18 to 28V. A solar controller charging a 12V battery needs over 18V input from the panel. Charging a 24V battery requires over 30V panel input. So a smaller panel is not suitable for charging a 24V battery. That's why a smaller panel is called a '12V' panel.

A larger panel will have a voltage of 30 to 40 volts. It is OK for charging a 24V battery, so it 's called a '24V' panel. An MPPT controller will be able to transform the high voltage output into something ideal for a 12V or 24V battery. If you connect the controller to a 12V battery before the panels are connected, it recognises the 12V battery and adjusts its settings to charge it properly..

A PWM controller like yours is OK for smaller '12V' panels like your 120W, or even two of them. If you want more than that, you'll need an MPPT controller. which will work with either type of panel, and will charge either type of battery, 12V or 24V.

 

[Billy192]

Go for the 300w and a MPPT. I have 2 325w and a 300Ah batt, with a victron MPPT. I plug in an extension lead when working in my garage and just use the van to power my tools. I have only done 1 weekend away due to work but my batt only went to 90% until morning and once sun up back to 100%.
Billy

 

[Romolo]

The victron systems look quite expensive. As in for my first older van so that my wife and I can understand what we like and don't like... I think that might be too much. We plan to keep this van for 2 years minimum maybe more as we are paying to have it fitted with lengthways fitted bed.

So need to watch the pennies Vs age of van.

Maybe this is too much of a push and I should just stick with going double battery as I intend. Possibly swapping to 2x 120watt brand new panels through existing cables and keep cost low?

Or do you think that Vs keeping 1 panel and 2x 110ah batteries is hardly noticeable?

Many thanks

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[autorouter]

There's a case for sticking with what you have until you feel you could definitely benefit from an improvement. Some people manage fine on a 100W panel and a 100Ah battery. The first upgrade is frequently a second battery, then a second panel, if you notice the battery level is lower than you want for longer than you want. The existing controller and wiring will be OK for that. The wiring safety isn't a problem, it's just there will be a bit more voltage drop when the amps are high and the sun is shining. But I'm sure you can live with that.