Portable Solar Panels

Helgar11 · Newbie

Portable Solar Panels

Dicko1 · Senior Member

Should be able to connect straight to the vans anderson plug with a regulated solar panel. However having 2 solar regs working at the same time could cause conflict. Cant damage anything so its worth a try to see if it works for you.

Whenarewethere · Guru

Better to use the one controller, so bypass the controller on the rear of the portable panels. They are in the wrong place to start with.

What is the capacity of the caravan's controller?

Can you insulate the fridge a bit more:

https://thegreynomads.activeboard.com/t65059593/extra-fridge-insulation-wattage-test/

Helgar11 · Newbie

Thanks for your response. The 12v Compressor fridge is built in to the caravan so cant insulate further. Can I ask how I bypass the solar panel controller and how do I connect the panels to the caravan?

The MPPT is a Voltech ISC3040. According to the manual, the Max Input Current is 30A dc, Max Input Open Circuit Voltage of 65Vdc and Max Load Current of 30Adc. I have zero knowledge of 12V so hope this helps

Mike Harding · Guru

You need to exercise some care in regard to the existing controller. It is likely the roof panels are wired in series thus presenting around 60V to the controller, you must not wire your new panels in parallel with the roof panels and, for many reasons, you should not wire your new panels in series with the roof panels. In short you cannot use your existing controller.

What you can do is to parallel the 12V output of your new controller with the 12V output of the existing controller - solar controllers are designed to handle this - if your caravan has a specific charging connector to connect to the car in order to charge the caravan's battery this is probably the best place to do so.

Given your lack of electrical knowledge I suggest you take caravan and car to an auto-electrician and ask him to look at it and advise what to do, he may well do so for free or maybe a slab of beer.

Edit: typo and unnecessary word.

-- Edited by Mike Harding on Thursday 24th of June 2021 02:24:06 PM

Wanda · Guru

Its not always possible, but when camping up for a few nights, and with no power, always park away from trees and check the direction of the sun. Before setting up get out and workout what the sun will be doing throughout the day into the afternoon.
Yes this goes against what we normally would do, particularly in warmer areas, but you NEED the sun. Make your shade with your awning or park away and shift your chairs to the shade.
I know we usually like to park near or under shady spots but with solar you need to plan your stops focusing on your solar input.
Large portable panels, had 2 sold 2, I find a pain to carry/store and then set up. I like the old KISS theory, "keep it simple st...d".
If you decide to get one look a those foldup panels, easier to carry and store and take up less room than the larger portable type
Not a sparky but I think extra panel through anderson should not go through 2 regulators, check with sparky.
cheers
Ian

Whenarewethere · Guru

I agree with Mike, get it looked at.

The controller doesn't have much headroom. If the solar panels are in series you can't do anything.

If the panels are not in series but in parallel. If you connect the new panel & the other panels or the portable panel at times are in the shade, you really should have diodes.

Looking at the retail price of an ISC3040 controller of $145.00 personally I would chuck it out & put in a new quality 100/50 smart controller. Add another panel to the roof, & have 2 panels in series, then in 2 parallel sets.

Get an auto electrician to set up a better long term system. It will cost a bit now but amortised over 10 years it will be money well spent.

The electrician can also check the rest of the wiring & make sure it is actually heavy enough.

Helgar11 · Newbie

Thanks everyone. Good advice for a green caravanner. As usual its better to get it looked at by a pro to save any hassles.

Peter_n_Margaret · Guru

There is absolutely no reason why you can not have multiple solar controllers (or other charge systems) feeding the same battery.
Each will do what it is set to do.
Cheers,
Peter

-- Edited by Peter_n_Margaret on Thursday 24th of June 2021 09:39:32 AM

Whenarewethere · Guru

I have a Victron 75/10 controller which was not large enough for my 120 watts, it was hitting the 10amp limit so I bought a 100/20 to replace it & with ideal conditions up to 11.3amps.

I did try both controllers together 40 watts on the 75/10 & 80 watts on the 100/20 & I could see that to some degree they were fighting each other. Not a lot but then this is a tiny amount of solar into 104AH.

Plain Truth · Guru

I have the light weight panels from kickass,you can bypass the panels solar controller quite easy,watch the video

I have the 150 watt,it has 3 panels light and easy. https://www.australiandirect.com.au/solar-panels/super-thin/

valiant81 · Guru

Hi all; I have 240 Watts of solar on the roof of our caravan and early this year i upgraded with another 220 Ah 12 volt agm battery. Had problems with little solar input, running 2 x 40 ltr Engle fridges,5Kw diesel heater, television and satellite receiver, lighting and the rest of the caravan, so the extra battery helps . I now feel that with 240 Watts of solar and 440 Ah of batteries , that the solar is not enough. We went camping down near sorell ( Tasmania ) a couple of weeks ago and with inclement weather,rain, fog for around 4 days that did not lift and the sun only came out on the 2nd last day. Even with my battery capacity after a nearly a week Had to recharge my batteries . Thank god one of the campers in out group had a small generator and a 10 Amp smart battery charger. This helped. The generator was real quiet and as the bush camp was nearly empty of other campers, the noise of the generator was not a problem.

So that is what i have done with my own set up is to carry a backup generator and charger. I now have a 2 Kw generator ( new ) and are waiting on a delivery of a 30 Amp 12 Volt smart charger. I'm not going to use the generator all the time but will be used for weather that does not have a lot of sunshine. The generator cost $350 and the Victron 12/30 battery charger was around $260. So for around $600.00 hopefully my setup now will be the end of my problems. Yes i could have gone down the way with extra solar panels either on the roof permanent or a folding panel of some sort, but when the sun doesn't shine, what to do !! The charger will live next to the house batteries and plugged in to the gpo under the bed for power. The generator on the other hand will be plugged into the 240 volt input for the caravan. The only things that need 240 volts really are the microwave, and the air conditioner. The hot water heater 240 volt element can be turned off and the microwave is mainly used for storage. The air conditioner as yet has not been tried out with the generator as it is also a 3 Kw capacity and would overload the generator ( start up current and all that ). Everything else uses 12 Volts power and hence the large amount of batteries. The victron charger will be connected to the house batteries all the time and when we are at home, the caravan will be connected to mains power. The charger will look after the house batteries and once charged, the charger will go into float mode.

darjak · Senior Member

If your Anderson plug on caravan runs directly back to batteries (yes)
But if you put a DCDC charger in you have to bypass the PWM on the solar panel.
I run my fold up panel thru a 40a DCDC charger to charge my aux battery in car and plug
Anderson plug on car to caravan Anderson plug in inclement weather. Try never to park
caravan under trees.
To bypass PWM on solar panel just use pushin connectors that way you can have either or
without having to mess around.

KevinJ · Senior Member

I was not aware of the two controller problem so I rang my caravan dealer to check on my circumstances. I have a grey anderson plug on the drawbar harness which connects to the car. I also have a grey anderson plug on the right hand side of the van behind the wheel to plug in a portable solar panel. This rear plug connects directly to the caravan battery so I need a controller on the portable solar panel. Another thing learnt about my rig thanks to the OPs question.

gdayjr · Senior Member

I have ordered a new caravan with 2x 200 a/h Lithium Ion batteries, and 3x 170w solar panels.

I aim to do as much free camping as possible, and i will have a generator for back up as well.

Is the amount of solar enough to keep those two batteries topped in in normal conditions.

I have asked the manufaturer if there is room for 4 pannels.

Just me in a 23.6 ft Crusader.

Dicko1 · Senior Member

gdayjr wrote:
I have ordered a new caravan with 2x 200 a/h Lithium Ion batteries, and 3x 170w solar panels.
I aim to do as much free camping as possible, and i will have a generator for back up as well.

Is the amount of solar enough to keep those two batteries topped in in normal conditions.
I have asked the manufaturer if there is room for 4 pannels.
Just me in a 23.6 ft Crusader.

Once again it comes down to how much power you use a day. I assume you will be running the fridge from gas as its a van. That really only leaves lights (hopefully LED,s) , tv? , and maybe a lapyop and phone charging> You will easily have more than enough power. Putting the 2 x 200 A/h batteries in paralell means you will have heaps of amps available to use a coffee macjine as well, if thats your thing. The fridge will be the biggest user of power (if it is the 3 way type) whilst connected to 12 volt and car is not running. However you will be quite easily be able to run the fridge for half a day just on batteries. I assume you are fitting a dcdc charger to cope with voltage drop from your vehicle. If there is room and your solar reg can handle the amperage I would definitely put another panel on the roof....once again you really need to know what appliances you will using and their power consumption. Do yourself a favour and read up as much as you can about solar systems for travelling. It will help with keeping the system well maintained and , hopefully, trouble free. Saves having to spend big dollars for someone to fix a cheap proble. Good luck.

oldbloke · Guru

Dicko1 wrote:
Should be able to connect straight to the vans anderson plug with a regulated solar panel. However having 2 solar regs working at the same time could cause conflict. Cant damage anything so its worth a try to see if it works for you.

My understanding is if it goes direct to battery this is correct.

I would just plug into the car and start thr car. If battery voltage increases due to the car alternater charging. I would then plug the portable in and check if batt voltage increases. If yes, all good to go.

Are We Lost · Guru

Dicko1 said "However you will be quite easily be able to run the fridge for half a day just on batteries. "

Not mine. The guideline should be to avoid discharging batteries lower than 50% capacity. My Dometic 186L 3 way fridge uses 25 amps if running on 12 volts. So I would reach the 50% limit in 4 hours, without any other usage.

Dicko1 · Senior Member

Are We Lost wrote:
Dicko1 said "However you will be quite easily be able to run the fridge for half a day just on batteries. "

Not mine. The guideline should be to avoid discharging batteries lower than 50% capacity. My Dometic 186L 3 way fridge uses 25 amps if running on 12 volts. So I would reach the 50% limit in 4 hours, without any other usage.

Your right mate...but I was talking about the posters lithium batteries that can go down to around 90%.