What size Solar panel should I buy?

[andy greenwood]

im looking for some advice please on solar panels for a pop top roof on our T6. Were new to this scene so we still have lots to learn about all things Vw so far all our trips have been on sites with electric hook up, next year we want to try several vw fests/gatherings. My concern is how do you power the fridge, charge phones, etc.. for a whole weekend without electric hook up ? we do have a leisure battery but i'm sure this wouldnt be enough to even power the fridge for a weekend . After reading some posts on here i was thinking maybe solar panels would do the job ? what sort of wattage would i need though? any advice would be great , thanks

 

[Lighty]

I'd be interested in any responses you get Andy. We've just had our van a few months and we've done a couple of festivals this year with no hook-up and I've ended up running the engine for half an hour every 24 hours or so to put a bit of juice back into the vehicle and leisure battery. I'm contemplating a solar panel for next year too

 

[Spaghetti]

Hi, and welcome.

I have a 110ah leisure battery, and we get two and a half days off grid (without starting the van), with the 12v fridge on so the freezer is iced up, using the lights, water pump and USB chargers etc. We use the diesel heater sparingly, as that seems to take quite a bit of electricity to run it.

The converters fitted a cheap split charge relay, and we used to book electric hook ups as the battery was always low. I recently fitted a CTEK 250SA charger, and the leisure battery is charged fully when we get on site, so for weekends, or where we’re running the van regularly, we don’t bother with hookup.

 

[Sjacko20]

We have a 150w panel and Victron smart solar MPPT 75/15 controller charging a 110ah AGM battery. So far (summer only) we have run the fridge, pump, usb and lights no problems for several days and the battery has maintained a high/full charge level even on dull days. My gut feeling is a 250w would be ideal as not sure yet how ours will perform on winter days. The controller is as important as the panel, we had a PWM one that really struggled to charge the battery but we still lasted 3 days with no issue however the MPPT we have now performs massively better.

 

[Dellmassive]

It's lookng like the sweet spot for solar is 100-300 watts of panels. Depending on demands.

The base kits always come with a PWM solar charger. It's recommended to upgrade that to a MPPT for a better conversion of solar energy.

One or more 110Ah deep-cycle leisure batteries are common.

We used a Colman 12v fridge on a 110ah leisure battery and it killed it in 24hrs.......

so how long your setup will last will depend on how much kit you have connected and drawing power...

During the summer months a decent solar setup should be able to replace the power drawn from your leisure batteries and keep you self sufficient.

If you need more run time for power then add another leisure battery. . . . . .

If the battery bank is not being topped up enough during the day in summer then add another solar panel.

Led lights and USB are low power . . . And will last a long time.

240v inverters with kettles and heaters plugged in will draw loads of power and drain your batteries faster.

I've gone for a mobile solar setup that I can take with me on trips and just deploy and plug in when Onsite. . . . I went for 100w Renology Suitcase panel and victron MPPT charger. And 2x 110ah leisure batteries..

I'll be adding another 100w Renology panel for next year to give 200w solar.

That should he enough to keep the batteries charged up.




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[andy greenwood]

Thanks guys, some great advice. I think i need to add another leisure battery but i cant decide whether to put solar panels on the pop top or just go for a mobile solar set up

 

[Nick1980]

I'm trying to decide on what size solar panel to install. I'm going to be off grid with little to no access to mains hook up. Van has a split charging system already to a 110ah leisure battery. Van will be running 8 X led lights, waeco fridge and will need to charge laptop / phone in the UK in winter.

Have read through as much of the solar info on here as possible to get an understanding of requirements

Will a 160w panel be sufficient or will I need more?

Any help or guidance would be appreciated.

Ta

 

[Fish]

Check out @Davenjo they have the holy grail of setup.. unlimited power 24/7

 

[stuart-t6]

I have a Victron 100w panel
And mppt controller.
It’s fine for me
In the summer off grid with fridge running and lights in the evening etc if that helps.
But Useless in the winter!

 

[Nick1980]

Heyup. Cheers for the link.

Really curious to know whether the system is working in winter. I'll be working away from home 3 nights a week so need to make sure when I'm parked up I've got enough power to last me. Seen people are using upto 250w panels and keen to understand what kind of experience they have had with their systems

 

[Nick1980]

Thanks Stuart. How it has performed in winter?

 

[Pete C]

You need direct sunlight to get decent power from a solar panel. A cloudy day is going to give quite limited power output. This is true whatever the season.

Pete

 

[stuart-t6]

Thanks Stuart. How it has performed in winter?

I get very little solar gain during the winter months and it’s the same for most people unless you have a lot or larger panels on the roof.
For this reason I have a sterling battery to battery charger so I can run my engine for an hr or so and charge up my leisure battery

 

[andys]

I have a 250W panel on mine and though I haven't used the van much over the winter, I'm addicted to checking the solar output over Bluetooth any time it's been outside. Over the winter I've observed a high of 47W in clear sky and a low of 7W in dark cloud and heavy rain. I would add that I don't let the battery discharge that much so it may have been that it was capable of pulling more if it needed it, also that was with roof down and the van facing east on the drive rather than pointing direct at the sun. Not very scientific I know but gives an idea.

 

[Salty Spuds]

Simple answer, “as big as you can”

 

[Nick1980]

Thanks for all the comments. I'm going to go with a 250w panel to start with and take it from there...

 

[DPDP]

Have a T6 T28 and thinking of solar panels so I dont have to rely on hook up all the time. I have an 85 ah liesure battery and I would like to keep battery topped up all the time. What size solar panel would I require? Im not technically minded so keep it simple please. Also any recommendations for fitting and price please. I live in South Yorkshire.

 

[Pete C]

What electrical things do you have in your van which run off the leisure battery ?

Pete

 

[DPDP]

Hi Pete. I run a fridge led lights and a few usb ports. Is it possible to run my diesel heater from the solar panel or is that wishful thinking?

 

[Pete C]

I don’t know how your diesel heater works, so difficult to answer. We run our gas heater from the leisure battery with no issues- the only real current draw is from the fan in the heater.

I would say you need 100W solar panel minimum, as we have much the same electrical equipment, and that works for us. But if you can afford more, then get more.

Have a look at the other threads on here to learn more about what is involved, and what others have done. The next big question is whether you want the panels permanently installed, or portable.

Pete