Is it enough solar

[Lanerboy]

I can get 335watts of solar on my roof (just) my question is, is this enough to off grid for say 2 to 3 weeks with 2 x 120ah lithium batteries and a victron controller

Also could i get my truma roof mounted ac unit re wired so it would run off the batteries and if so would it work ok or would it just kill the batteries

Many thanks

 

[Stealaway]

That's a lot of weight on the roof but if the sun is shining you can stay forever.

 

[Keypresser]

We went off grid touring Scotland for 2 months with 2 wet batteries and 2 x 100watt panels. It all depends what power you pull from the batteries, how much direct sunlight you get and how many road miles you do (supplementary charging).
I think the ac might be a much but there are others that will pitch in.
Best to do a trial run and suck it and see.

 

[eddie]

I can get 335watts of solar on my roof (just) my question is, is this enough to off grid for say 2 to 3 weeks with 2 x 120ah lithium batteries and a victron controller

In June probably

I have 3 x 175w panels and don't really need hook up in the Summer

Also could i get my truma roof mounted ac unit re wired so it would run off the batteries and if so would it work ok or would it just kill the batteries

Many thanks

It will kill the batteries

 

[Bessy765]

Twe have 700 watts of solar with a Victron 2000/80, and two 100 amp Transporter Lithium batteries. Also have a Freshjet 2200 habitation air/con. This is set up so it can be run via the inverter. It draws 112 amps @ 12 volt d.c. to run it. It’s not so much whether your system will power it, its how long it takes to recover what you have used. My 4 x 175 watt panels would at most produce app 40 amps max per hour and that would be only when the sun is high. Admittedly the air con will cycle on and off if not set too low but it would not give more than a couple of hours use a day without depleting the batteries for other uses. With the monitoring of the system that in itself uses 14 to 18 amps a day.

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[Richard n Ann]

We just had a freestanding 40w panel for the first few years and managed perfectly well. Ann just had the TV on for a couple of hours in the evening, LED lighting and charging phones.
So it all depends on what you're using. We've got a fixed 150w panel now and stay off grid for 8+ weeks in Benidorm.

Shade is your biggest enemy, even a lamp post casting a shade will reduce output by 50%..

 

[Lanerboy]

Update after getting on the roof and measuring another 3 times i can now confidently get 455 watts using 5 victron panels 3 x 115w and 2 x 55w, as they say every little helps

 

[Reallyretired]

Air con can be run through an inverter but uses a lot of power. Pity nobody does gas powered Air con, it must be possible.

 

[Raul]

Update after getting on the roof and measuring another 3 times i can now confidently get 455 watts using 5 victron panels 3 x 115w and 2 x 55w, as they say every little helps

Are you aware that you can get 400w in a single panel now? Why 4 panels plus two?

 

[Lanerboy]

Are you aware that you can get 400w in a single panel now? Why 4 panels plus two?

Because i have so much on my roof, 5 skylights, sat dish, air con unit, i can only do it using smaller panels to fit in the gaps

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[BDM]

Are you aware that you can get 400w in a single panel now? Why 4 panels plus two?

Craig solar have some very usefull sizes, but I don't know how Raul would rate them.

 

[The Wino]

I can get 335watts of solar on my roof (just) my question is, is this enough to off grid for say 2 to 3 weeks with 2 x 120ah lithium batteries and a victron controller

Also could i get my truma roof mounted ac unit re wired so it would run off the batteries and if so would it work ok or would it just kill the batteries

Many thanks

Depends what you use apart from the Aircon the concensus seems that isn't doable. We had no solar and only a 90 ah lead acid but managed fine without hookup touring aires in France. I've since added a 100w panel when bored in lockdown but we're pretty light users of electric. You can either adjust what you use to the capacity you already have or alter capacity to what you might want to use but if with the exception of the aircon you aren't getting low on battery at present what you have already must be adequate.

 

[Raul]

Craig solar have some very usefull sizes, but I don't know how Raul would rate them.

I have not used them, but, have no reason not to trust them. They look good quality mono, with good specifications. In fact, I did wanted two for a portable folded, but at the time it was sold out. Hence went to victron small panels.

 

[Maitken1]

You should be fine with what you have as long as you have a 3 way fridge running on gas. The lithium battery should also be enough. All of this provided you have sun at least every few days. Don't run the aircon at all off grid, as it won't run for long before the battery goes flat. The inverter uses some amps to just run as well as the aircon will draw a lot of amps when the compressor is on. The good thing about lithium is that running it flat doesn't hurt the battery and the useful capacity if far higher than AGM.

 

[Carpmart]

Craig solar have some very usefull sizes, but I don't know how Raul would rate them.

I’ve two x 200W Craig solar panels; working well. Great service from them as a vendor when I purchased. Recommended!

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[jumar]

We have One 200w fixed panel on roof...One 90ah Lead Acid battery and can do everything all year round..why motorhomes have Aircon fitted I do not get....Park in a shady location...then your van is cooler...but your Panels won't work...of course...I have a folding panel that get put in the sun, while the van and it's occupants are in the shade...

 

[jongood]

Because i have so much on my roof, 5 skylights, sat dish, air con unit, i can only do it using smaller panels to fit in the gaps

I have 600w on my roof. We re in Spain now and I've been experimenting with angles on one 100w panel ( ready for being back in uk ) my whole settup was giving about 14 amps ,( because the sun was also fairly low) and when I tilted that one panel about 20° I was getting an extra amp. My logic is is if I can arrange to be able to tilt my 2 x185s up to 40° I could maybe get another 4 amps which would make a big difference in UK.

The other thing I'm contemplating is either ditching or converting my satellite dish.

 

[jumar]

I have 600w on my roof. We re in Spain now and I've been experimenting with angles on one 100w panel ( ready for being back in uk ) my whole settup was giving about 14 amps ,( because the sun was also fairly low) and when I tilted that one panel about 20° I was getting an extra amp. My logic is is if I can arrange to be able to tilt my 2 x185s up to 40° I could maybe get another 4 amps which would make a big difference in UK.

The other thing I'm contemplating is either ditching or converting my satellite dish.

I'm a avid believer of tilting my one and only roof mounted 200w panel...
Calculating in watts it was giving me 40w while flat but tilting it produced 148w....see photo....my folding panel was charging my eBike via a Powerpack...

 

[funflair]

I have 600w on my roof. We re in Spain now and I've been experimenting with angles on one 100w panel ( ready for being back in uk ) my whole settup was giving about 14 amps ,( because the sun was also fairly low) and when I tilted that one panel about 20° I was getting an extra amp. My logic is is if I can arrange to be able to tilt my 2 x185s up to 40° I could maybe get another 4 amps which would make a big difference in UK.

The other thing I'm contemplating is either ditching or converting my satellite dish.

This is what you want Jon, 4000 watts of solar

 

[JonnyMac]

12v A/C is an option i'm thinking about installing before heading to France this summer.

12V Air Conditioners: Battery Powered for Off-The-Grid Vanlife - FarOutRide

12V air conditioners are more efficient than 120V and is the key to off-the-grid "battery powered" A/C. Wiring diagram & items list inside!

faroutride.com

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[funflair]

12v A/C is an option i'm thinking about installing before heading to France this summer.

12V Air Conditioners: Battery Powered for Off-The-Grid Vanlife - FarOutRide

12V air conditioners are more efficient than 120V and is the key to off-the-grid "battery powered" A/C. Wiring diagram & items list inside!

faroutride.com

It doesn't matter whether it is 12v or 240v you still need decent battery capacity to run it.

 

[Vennwood]

I can get 335watts of solar on my roof (just) my question is, is this enough to off grid for say 2 to 3 weeks with 2 x 120ah lithium batteries and a victron controller

Also could i get my truma roof mounted ac unit re wired so it would run off the batteries and if so would it work ok or would it just kill the batteries

Many thanks

For over 10 years we had around 435W on the roof and 800AH GEL batteries with a 4000W pure sine inverter and found we could survive off grid indefinately during summer but sometimes would struggle to stay off gride for more than a couple of weeks during the depths of winter - particularly in UK. To be fair we are big users of 240v power with microwave, coffee machine and electric kettle in addition to the usual phone and kindle chargers. Certainly in winter we would revert to our trusty kettle on the gas hob. We had a Dometic Aircon unit but found it was a non starter at any time when off grid as it would only last for a couple of hours or so as others have said. It was a balance as if you used the aircon then you couldn't use your other appliances until the sun had recharged the batteries. We did have a neighbour who had one of the Aiden GPS controlled panels and that was brilliant - especially in winter when often his single tilted panel produced more than my 4 times more flat panel. Don't know if they are still available but tilting panels would be a better option in terms of power generation on a like for like basis. (cost not taken into consideration of course) Finally - regular cleaning of the panels especially in winter made a huge difference

 

[MobyDick57]

We have 2 arrays of solar panels - one 175w x 2 & 100w slims x 4, total 750w. Presently near Marbella and pulling max 22amps per hour, harvesting max 85ah per day. We also have 6 x 100amh transporter lithium batteries. We use about 80 - 100 Ah per day. Accounting for cloudy days we are self sufficient, however we would not have sufficient energy to power a aircon unit. We find the solar panels help keep the van cool due to their shade

 

[funflair]

We have 2 arrays of solar panels - one 175w x 2 & 100w slims x 4, total 750w. Presently near Marbella and pulling max 22amps per hour, harvesting max 85ah per day. We also have 6 x 100amh transporter lithium batteries. We use about 80 - 100 Ah per day. Accounting for cloudy days we are self sufficient, however we would not have sufficient energy to power a aircon unit. We find the solar panels help keep the van cool due to their shade

I assume that you are seeing more like 50 amps when the sun gets higher, I have seen 40 amps from our 560 watts and can run the air con for a good few hours off 480ah LiFePO4.

 

[MobyDick57]

When the sun is at its optimum in summer in uk can pull 50amps/hour, however this winter Spain, so less

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[two]

I can last 5 days without EHU and 80Ah capacity.
It depends on how much you consume, of course but, if I had 400W of solar, I'd hardly need any batteries at all.

 

[Richard n Ann]

If your batteries are recharged by sunset you can last off grid indefinitely. Our battery is usually fully recharged by lunchtime or just after.

 

[MobyDick57]

The simpler concept I saw in Portugal was a kind of elasticated white cloth cap fixed around the skylights. This allowed a light breeze through the van via the side windows through the skylights, BUT did not allow the noon day sun in. The light coloured cloth allowed light in, but vastly reduced the heat of the sun in

 

[rapido740]

I keep thinking of making a straw box on the roof. Just straw a fan and a tiny water pump
to keep straw wet. We used them in Oz and they give a lovely cool room. I hated AC when we lived in Nigeria always giving us sore throats not to mention the noise It’s a diy project

 

[eddie]

I keep thinking of making a straw box on the roof. Just straw a fan and a tiny water pump
to keep straw wet. We used them in Oz and they give a lovely cool room. I hated AC when we lived in Nigeria always giving us sore throats not to mention the noise It’s a diy project

There used to be a 12 volt product called Blizzard which was a similar principal.

Heavy breaking used to get water slopping out of it and everyone with evaporative coolers was getting paranoid about Legionaries Disease

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