Solar Panel Size

[Billyn]

We just purchased our first Motorhome (Autosleeper Broadway) and we are trying to find out what size of solar panel we would need (watts) and battery set up so that we can be off grid at times. So enough to power our firdge/tv etc. Any assistance much appreciated. Bill

 

[Jimbohorlicks]

Best if you can measure out your roof first. A photo from above and add some dimensions. Then you can determine the max amount of solar you can fit.
What is your battery capacity now and what type of battery is it. Lithium agm gel lead acid? Do you want to change to lithium if not already?
How long were you thinking of being off grid for do you wantvtonuse other appliancescrequiringvan inverter. Kettle hob airfryer microwave?
Are you able to fit panels yourself with the correct controllers ?
Lots of questions.

 

[MisterB]

What type of fridge? If it's three way then it won't work on 12v off grid?
A 12v compressor fridge will, as would 240v compressor fridge with a dedicated inverter.

As regards what size battery, my suggestion would be the biggest lithium you can afford that will fit in the space available, same for solar panels.

 

[Billyn]

Best if you can measure out your roof first. A photo from above and add some dimensions. Then you can determine the max amount of solar you can fit.
What is your battery capacity now and what type of battery is it. Lithium agm gel lead acid? Do you want to change to lithium if not already?
How long were you thinking of being off grid for do you wantvtonuse other appliancescrequiringvan inverter. Kettle hob airfryer microwave?
Are you able to fit panels yourself with the correct controllers ?
Lots of questions.

TBH we are not really sure, it was more about being able to have the odd night off grid particularly when doing things like NC500 etc. Lots for me to think about...many thanks.

 

[Billyn]

What type of fridge? If it's three way then it won't work on 12v off grid?
A 12v compressor fridge will, as would 240v compressor fridge with a dedicated inverter.

As regards what size battery, my suggestion would be the biggest lithium you can afford that will fit in the space available, same for solar panels.

Great, that gives us something to work with. Were are changing to Lithium and will need to look into what we can get on the roof in terms of panel. I was thinking a 300 watt but again I'm new to this so will take all the advice I can get. Thank you for your help! B

^{_{Subscribers  do not see these advertisements}}

 

[Jabstatt]

Keep an open mind!

We run our three way off 12v but only because I can’t find a compressor fridge to fit

Tony

 

[Jev88]

Solar - fit as much as budget, space and weight allow.

If you have a 3 way fridge and not on EHU you will be using gas for fridge

 

[Purrfecttune]

As a guide (from a relative ‘newbie’) we started with 80ma lead acid and 100 watt solar panel.

No B2B, just shared charging with the alternator.

Our maximum time with no EHU in Spain was three days. In the UK we had to drive daily to keep it above 50%.

Used gas for hot water, heating, fridge and cooker.

We now have:
280ah lithium battery
Total of 275w solar
B2B
1200w inverter

We can now go indefinitely without EHU in Spain and probably 10 - 14 days in the UK based on our personal usage (staying in one place).
We also use a lot less gas as we now hardly use the cooker, instead utilising air fryer, toaster, electric kettle and occasionally microwave.

 

[MisterB]

Keep an open mind!

We run our three way off 12v but only because I can’t find a compressor fridge to fit

Tony

There are a couple of Funsters who run a domestic 240v compressor fridge via a dedicated inverter when off EHU with no issues whatsoever! Perhaps a domestic one might fit?

Even if you can find a 12v compressor fridge to fit, it can be an expensive swap! We were luckily able to sell our three way for a fair price, but it still cost a fair old whack ...

 

[MisterB]

Great, that gives us something to work with. Were are changing to Lithium and will need to look into what we can get on the roof in terms of panel. I was thinking a 300 watt but again I'm new to this so will take all the advice I can get. Thank you for your help! B

I think everyone would agree that lithium is a decent upgrade but plenty survive without it!

The key, in my mind, is being able to replenish whatever you use in as short a time as possible. If you can't replenish it quickly enough then either stop using it or increase your capacity for either charging or stored power.

Going onto a site to recharge your battery every few days is a damn site cheaper than installing lithium in the short term.

I like having lithium, it does what I want and more importantly what I need and allows me to do things in a way I like to do them BUT plenty manage perfectly without lithium!

^{_{Subscribers  do not see these advertisements}}

 

[KASPAR]

There are a couple of excellent small companies that are recommended on here to help you figure things out. They offer discounts too.

Off Grid Power Solutions in Wantage nigelivy RogerIvy https://offgridpower.solutions/

WattGuardz in Taunton AshWattGuardz https://www.wattguardz.com/

Both do high quality work at reasonable prices.

 

[Purrfecttune]

One of the most noticeable changes for us was the B2B. When the lead acid was down to about 60% a three hour drive charged it up to maybe about 85%, so not really enough.

With the B2B a similar drive time would almost fully recharge the battery, so when we were touring Spain this year, the battery was fully charged after every drive. I have read that some people who stay in one place for an extended period with not enough sun for the solar, simply run their engine for a short time for their B2B to top it up.

 

[Growly bear]

Keep an open mind!

We run our three way off 12v but only because I can’t find a compressor fridge to fit

Tony

I was in the same position, so converted my Dometic RMS8501 into a compressor fridge. No freezer now, but the fridge is huge! Happy to talk it over. My plan is to write it up over summer from start to finish in my Exsis I 414

 

[Billyn]

As a guide (from a relative ‘newbie’) we started with 80ma lead acid and 100 watt solar panel.

No B2B, just shared charging with the alternator.

Our maximum time with no EHU in Spain was three days. In the UK we had to drive daily to keep it above 50%.

Used gas for hot water, heating, fridge and cooker.

We now have:
280ah lithium battery
Total of 275w solar
B2B
1200w inverter

We can now go indefinitely without EHU in Spain and probably 10 - 14 days in the UK based on our personal usage (staying in one place).
We also use a lot less gas as we now hardly use the cooker, instead utilising air fryer, toaster, electric kettle and occasionally microwave.

Excellent, looks like exactly what we need to be doing to meet all our needs. Many Thanks.

 

[Billyn]

Excellent, looks like exactly what we need to be doing to meet all our needs. Many Thanks.

^{_{Subscribers  do not see these advertisements}}

 

[1967bowesj]

Excellent, looks like exactly what we need to be doing to meet all our needs. Many Thanks.

Unfortunately you have used your 5 free posts, as you can see it's worth joining!