Solar Panels for newbies...

[The Saints]

Hi Folks. Just joined the Fun and have some questions about the fitting/use/suitability of solar energy.

We live in France.

We're experienced caravaners but now making the move to a MH. We've seen one that fits the bill nicely but has no panels fitted, although it has 2 x 150 lithium batteries fitted in the garage.

The salesman refuses to budge in the price as it's been discounted from its original price. It's a 2022 model, with just over 7000 kms on the clock and is like new.

So I thought I might get a better deal if I ask for some goodies to be included in the ticket price. He has agreed to include some panels but only 200w.

We plan on going off grid a fair bit in southern Europe, so plenty of sunshine. Campsites with EHU a couple of times a week.

So my question is this. Will 200w of solar be enough or should I push for 400w...? Or ask for another battery..?

We use our phones and laptop quite a bit and an hour or two of TV every day. Gas cooking and electric only fridge.

If 200w is likely to be OK, then I'll find some other things to be included in the price.

Thanks in advance..

Graham

 

[lorger]

Hi and welcome, we have a 125ah lithium with 180w solar, in the summer it’s fine even here in Scotland however during our trip to Portugal and Spain throughout Nov and Dec it struggled some days due to low sun. I would try and get as much as you can even if not free you could pay for more and also think about a B2B as you could ask the dealer to fit that as part of the deal.

 

[The Saints]

Thank you.

I suppose I have to think where my priorities are. Should I push for higher panel ratings or another 150w battery.

And I'm afraid B2B means nothing to me..!

Is there an idiots guide to solar panel use on the forum...?

 

[Guigsy]

I've got 280Ah of lithium, 175w of solar. I'm a fairly low energy user (no inverter and the fridge is 3-way), so I'm finding that I can last nearly a week without any sunshine at all. Before I'd put a 30A B2B in (the DC charger that gives you juice from the alternator), I wasn't getting much charge from driving about. During a 3 week trip around Ireland in October (it was wet!), I was slowly depleting the battery over days and then recharging it when I went to a site with EHU. Basically, 280Ah for me is total overkill.

200w of solar in Europe in summer will yield quite a lot of Ah per day. It should easily cover the fridge and a fair amount of TV and laptop use. It'll take several dull days to run down 300Ah of lithium. With some driving around an a hookup every few days, it should be fine. If you want to use it in the UK in the spring and autumn, and off-grid for extended periods, then additional panels will be useful. In the UK, by the time you get to October until about March, roof mounted flat solar is mostly useless no matter how much you've got.

 

[lorger]

Thank you.

I suppose I have to think where my priorities are. Should I push for higher panel ratings or another 150w battery.

And I'm afraid B2B means nothing to me..!

Is there an idiots guide to solar panel use on the forum...?

Sorry for that B2B means battery to battery charger, I’m not electrical so this is basic but maybe Lenny HB can explain better. A B2B is connected to you alternator and is like a fast charger so if you’re driving every couple of days your battery will be charged quickly.

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[WillysMB]

we have a 300w solar and a 220 Lithium (on a 2023 chassis) ... we run out of space in our toilet cassette before we run out of power. On average ( low user) we use 10-15% per night and can recover that in full sun or half that in cloud ( roughly)
200W solar with 300W Li batts ...I really wouldn't worry ...

 

[Jev88]

Simple explanation of solar power on your Motorhome.

More panels = more harvest.
More batteries = more stored power.

Then a solar controller sits between your panels and batteries. It takes the solar power and pushes it into your batteries. Once fitted you can forget it. No turning on and off or flicking switches.

 

[RogerIvy]

There are two upgrades that I’ve never known anyone to regret:

1. Lithium (LiFePO4) battery with good DC-DC (B2B) charger
2. As much solar as the roof can take (within reason … lack of payload and budget can get in the way)

In direct answer to your question I’d go for the 400w option (I actually have 645w) and two 280ah batteries.

 

[suavecarve]

With how you have explained your usage of electricity, the amount of ah you have and 200 watts in europe, I would look at something else like an awning or LPG or tv aerial or extra casette or any mixture of them and anything else. In short, I think youre covered on the electric

 

[Lenny HB]

Being a 2022 van it should have a B2B.

300Ah of Lithium is quite a reasonable size there is no point in having large batteries without the means to charge them so 400 watts of solar would be a good option to go for.

Dealers often fit cheap & nasty solar controllers meaning you will never get the best out of your panels.
It's worth pushing for a Victron MPPT controller even if you have to pay for it.

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[oldiesontour]

As said it should have a DC/DC charger so go for max solar and insist on a MPPT solar controller

 

[Just smiffy]

You can never have too much solar….

 

[daventess]

You can never have too much solar….

Tell that to Katie Price ...

 

[The Saints]

Thanks for all the great advice, really appreciate it.

It seems we agree that 400w of solar together with 300ah lithium is a reasonable balance, but any improvement in his offer should be for beefier panels than the 200w he's offering at the moment..

Don't relax, I'll be back with more questions soon...!!

 

[Guigsy]

You can never have too much solar….

I disagree. After a point, its deminishing returns. It's useless for a fair bit of the year in the UK no matter how much you've got. And if you can get out of the mentality that the battery needs to be full every, you can get away with surprisingly little.

If you're primarily using a van in Europe through the summer, and you stay at a site every 5-10 days to empty the cassette and do the washing, then 200w will be fine. Especially if you're moving about a bit and the B2B is fairly strong.

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[oldiesontour]

I think the more solar the better.. it's comparatively cheap &largely maintainance free..Not for when there's lots of sun but when there is little sun..if yield is 10% then 400w will just about keep up with a compressor fridge ,200w will not ,with many sites now changing separately for ehu at as much as £5/6 per night at around 50p per watt of panel the return can be fairly quick...

 

[TrudeandDall]

I have friends in France who didn't go for solar because of the summer heat and the fact that to keep cool the vsn needs to be in the shade.
They opted for more battery storage and a decent sized B2B.

 

[The Saints]

It's true that it can get a bit toasty down here, mainly in July and August when it's hovering around 32-36C.

We're often on a site then and can use AC.

For the other 10 months of the year I think solar is going to be essential for us.

 

[the1andonly]

I am in the no such thing as too much solar camp. I am solared for non sunny times, van started with 120 and i added 100 and 330 so 550W (£210 spent)(about £280 on Votronics chargers, +£? for b2b) but @£600 for 100Ah Li. Enough power even for a week in November. todays battery prices may change the equation slightly but i'm more than happy with situation of not using all suns rays, otherwise I wouldnt wear a sun hat and sunblock.

 

[LithiumConvert]

For many of us, more solar is not an option because of the weight of the panels.
and, as stated above, limited use in the UK for half of the year.

I think it is better to go for a variety of charging methods including a good B2B and EHU charger.
As well as some solar with a good MPPT controller.

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[The Saints]

Thanks for all your help, I really appreciate it.

We've put a deposit on the van, having agreed that he would fit 2 x 200w panels.

I had a closer look in the garage and found that there were 2 x 100ah lithium batteries, not the 2 x 150ah mentioned in the blurb. He apologised, I think it was a genuine mistake on his part. But he wasn't up for swapping the batteries and having seen the prices, I understand why...!

But there is room for a third battery so I'll see how it goes and add one if necessary.

Cheers

Graham

 

[jumar]

I think You've done well...getting two panels fitted...I would stick at that for now.
Although you have just two smaller lithium that you expected...you have enough, and as you draw power off them your panels will replenish....if it's sunny..only cloudy days will you notice that your 12v supply isn't up to it....or is it...We did 2 years on one 160ah Lithium before upgrading to more lithium..but we charge eBikes..and live in Spain...
I'm sure you will be fine....

 

[funflair]

Hi Graham

We are currently in New Zealand and running on a 120ah lead acid battery and about 150 watts of solar, this runs the small compressor fridge and any other stuff we need, when we are back home we have 640ah of lithium and 520watts of solar, they both work but of course our home set up gives us loads more options, if you go for the 400watts of solar, another battery and then an inverter to supply 240 voits it means that many of your “hook up only” appliances like kettle coffee machine and microwave will all still be available to you, welcome to the bottomless pit of spending that is motorhomes

 

[Abgs]

Another view …

We are four weeks into a trip at the moment; UK, France, Spain and Morocco.

We have no solar at all! … just a 320ah lithium battery and a B2B which is giving about 60a charge per hour while driving.

We are using about 90a per day without being particularly careful. That’s running the battery powered fridge, regular use of the electric kettle on the inverter, plus occasional use of the air fryer, toaster, Ebike charger, laptop charger and TV. In addition the MLt seems to draw 15a per day when it’s doing nothing plus the interior Blackpool illuminations which are standard on this Hymer.

We are stopping maximum three days at a time but generally moving after two and recharging while driving

We have only plugged into EHU once in Spain as it was free, but we didn’t really need to. It just saved a touch of diesel by using electric to power the heating and hot water.

Yes, we do need some solar just to take away the anxiety.

We are aiming for a comfortable 7 - 10 days of electrical self sufficiency.

Our current thinking is 200- 300 watts on the roof plus a portable 200 watt folding panel. Lots of people were using the folding panels in Morocco as with the sun being low in the sky at this time of year it’s easier to point the panels at the best angle for maximum solar harvest.

 

[jumar]

Freestanding is a game changer...even in summer...
Van in the shade panel in the sun

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[EuroTrotters]

Thanks for all your help, I really appreciate it.

We've put a deposit on the van, having agreed that he would fit 2 x 200w panels.

I had a closer look in the garage and found that there were 2 x 100ah lithium batteries, not the 2 x 150ah mentioned in the blurb. He apologised, I think it was a genuine mistake on his part. But he wasn't up for swapping the batteries and having seen the prices, I understand why...!

But there is room for a third battery so I'll see how it goes and add one if necessary.

Cheers

Graham

480w solar
105ah lithium
Victron B2B
Victron Solar charger
Victron 2000va inverter

We just need another battery

I hope this helps ?

 

[MisterB]

Freestanding is a game changer...even in summer...
Van in the shade panel in the sun

Fitting an Anderson connector in the motorhome skirt really helps with the folding solar. I am tempted to look at a 200w to replace our 120w ......

 

[Just smiffy]

400w of solar 1000w inverter powering the electric kettle toaster remoska compressor fridge and charging stuff… victron b2b while driving and I don’t plug in to EHU…. And I’ve got 2 85amp gels…

But when I’m back in the uk I’ll get a 280 lithium…

 

[jumar]

Fitting an Anderson connector in the motorhome skirt really helps with the folding solar. I am tempted to look at a 200w to replace our 120w ......

Yep...similar to my choice of connection..
I have a short fly-lead...that's is permanently connected to a mppt controller 100/15..Victron..The cable is stowed in the gas locker and it's quick to extend this to our 200w Allpowers panel..
Outstripped our 200w roof on many occasions..but only last week I added another 200w roof panel..

 

[MisterB]

Yep...similar to my choice of connection..
I have a short fly-lead...that's is permanently connected to a mppt controller 100/15..Victron..The cable is stowed in the gas locker and it's quick to extend this to our 200w Allpowers panel..
Outstripped our 200w roof on many occasions..but only last week I added another 200w roof panel..

I'm actually thinking of adding at least one more Anderson connector to the motorhome on the other side and the rear, why? Because I can.
if I use the solar in those locations, I can then reduce the length of the fly lead (not to reduce weight, but it's easier to stow a 1m cable than an 8m cable)
I was a bit wary of having cables running through open (or closed) locker doors, but if it works for you, as it obviously does, then it's a good option!

So, does anyone make use of Anderson connectors for other 'stuff'? We can use ours to power the Starlink aswell as solar. Awning or festoon lights are another option, though we haven't got them. We did think of using a tyre compressor, but recently bought a battery powered jump starter with in built tyre compressor, so don't need that option.

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