Connecting portable solar panel to van

Gus1949 · Senior Member

Connecting portable solar panel to van

oldbobsbus · Guru

IF the panel has a built in regulator then that would work but if it doesn't then you would need to send the power through a regulator before the battery as I have seen 12v solar panels putting out 29v..

If I was doing it either way I would wire in an Anderson plug using 6 B&S cable to a convenient place on the van and then fit the end of the panel lead with an Anderson plug..

Dougwe · Chief one feather

Gus, I agree with Bob, Anderson plug is the way to go.

I have what normally is a fixed 120w Solar panel that I use as a portable so I can follow the sun all day when stationary. I changed the wiring on the back of the panel to 6B&S and about 30cm of cable with Anderson on end. To that I attach a 5mt length of 6B&S cable via another Anderson then connected to the back of the Den to another Anderson. That then runs direct to my Ctek Duel DC - DC Smart charger and from that to the battery. No power loss all the way through.

PeterD · Guru

The main purpose of your Setec main purpose is to supply 12 V DC power to your lights, radio, water pump and anything else that runs on battery voltage. It is an excellent piece of equipment for that. It's secondary purpose is to trickle charge a battery and connect that battery to the 12 V system when mains power is is not available. It is not a very good battery charger.

The Setec also has a feed through for 12 V power from your tugs alternator to also charge the battery. It does not boost the voltage from that connection. In fact it has a diode in circuit to stop the battery from supplying the 12 V operation of your fridge. This diode drops the voltage a little. If you have a solar panel with a regulator on it the voltage drop in that diode will reduce the voltage from the panel so you will not get a good charge from your panel.This input can also be used to power the 12 V circuits from your tugs battery when the van is not equipped with a battery

Also if you have a Jayco van with a 12 pin plug then the factory will have wired pin 10 as the high current earth and the positive goes via pin 9. If it is wired any other way then someone has fiddled with it.

You say you already have a panel on the roof. What size is it and what regulator do you have in your van to control the charge to the battery? If the controller is large enough you can simply connect your extra panel to that controller in parallel with the existing one. You will get very poor charging from your van if you connect the movable panel through the trailer plug. Let us know what is already installed and we can work out if the controller can handle both panels. The only efficient option for adding solar charging to yout battery in a Jayco van is to connect it directly to the battery.

In the functional diagram below you will see the diode symbol in the line from the DC external input.

Setec Functional Diagram 1 & 2.JPG

Gus1949 · Senior Member

Thanks guys for the advice. I wasn't sure what the capabilities of the Setec were, thought it may incorporate a decent DC/DC charger function. Looks like the way to go is to bypass the regulator on the panel, install a decent DC/DC charger and use 6B&S all the way through with Andersons. My main concern is to ensure the batteries have a reasonable chance of attaining full charge when free camping. We have a 12v/240v compressor fridge in the van as we believe they perform better in the tropics, don't want warm beer!

Any suggestions on what make/model of DC/DC?

Gus.

PeterD · Guru

Gus1949 wrote:
Looks like the way to go is to bypass the regulator on the panel, install a decent DC/DC charger and use 6B&S all the way through with Andersons.

Why are you insisting on using a DC/DC charger to work with a solar array? It is the wrong equipment to use. A DC/DC charger requires a solid DC source like a vehicle alternator. The DC/DC charger requires sufficient current to drive it at its full output, if there is insufficient input it closes down. A 120 W solar array will only will only deliver a maximum of around 7 A, a DC/DC charger will require 20 - 50 A to drive it properly.

As I said earlier, a solar controller is the way to go. I have asked you to tell us what you have already installed in your van but you have not replied. If the regulator you have in the van for your existing panel on the roof is suitable then you run your new cable (via a plug and socket) from the portable panel directly to the existing controller. You will not achieve much extra by adding extra equipment, just an unnecessary large expense. If you desire to add a DC/DC charger to charge from your alternator in addition to what you are now attempting to achieve, there are a couple of manufacturers that incorporate solar controllers in their chagers so you can have the best of both worlds in the one package. However using a DC/DC charger with your solar panel just will not work.

For heavens sake answer the questions we ask of you if you really want assistance. We can not give you a full and sensible response unless you do. What is the existing controller?

In addition, 6 B&S (18 mm2) cable is way overkill for a 7 A current from a solar panel 6 or 8 mm2 cable will be sufficient.

Gus1949 · Senior Member

I am on a steep learning curve with this stuff please accept my apology for tardiness in my reply. I thought DC/DC was what was required to boost the voltage so the batteries would fully charge, didn't know that only works off the alternator. The regulator on the fixed solar panel is a Coast to Coast TPS555 with a max. input and load currents of 30A. Unfortunately where Jayco have placed it in the van, 150mm below the roofline half way down the van in a cupboard makes it practically impossible to connect a portable solar panel to it. I think we will need a second controller in the front boot, which will but it within 200mm of the batteries. I understand what you said about the wire gauge, thanks.

Gus

SnowT · Guru

It sounds like it might not be to hard to run Cabling from the Regulator to a point Outside...
- just need to map a Route...

Juergen

wasn_me · Guru

PeterD wrote:
Gus1949 wrote:
Looks like the way to go is to bypass the regulator on the panel, install a decent DC/DC charger and use 6B&S all the way through with Andersons.
Why are you insisting on using a DC/DC charger to work with a solar array? It is the wrong equipment to use. A DC/DC charger requires a solid DC source like a vehicle alternator. The DC/DC charger requires sufficient current to drive it at its full output, if there is insufficient input it closes down. A 120 W solar array will only will only deliver a maximum of around 7 A, a DC/DC charger will require 20 - 50 A to drive it properly.
As I said earlier, a solar controller is the way to go. I have asked you to tell us what you have already installed in your van but you have not replied. If the regulator you have in the van for your existing panel on the roof is suitable then you run your new cable (via a plug and socket) from the portable panel directly to the existing controller. You will not achieve much extra by adding extra equipment, just an unnecessary large expense. If you desire to add a DC/DC charger to charge from your alternator in addition to what you are now attempting to achieve, there are a couple of manufacturers that incorporate solar controllers in their chagers so you can have the best of both worlds in the one package. However using a DC/DC charger with your solar panel just will not work.
For heavens sake answer the questions we ask of you if you really want assistance. We can not give you a full and sensible response unless you do. What is the existing controller?
In addition, 6 B&S (18 mm2) cable is way overkill for a 7 A current from a solar panel 6 or 8 mm2 cable will be sufficient.

Hi Peter,

Am I correct in assuming you would bypass or remove the regulator on the portable panel with this set up?

Cheers Pete

PeterD · Guru

wasn_me wrote:
PeterD wrote:
Am I correct in assuming you would bypass or remove the regulator on the portable panel with this set up?

You should never have two regulators in series, you will loose too much potential power. The regulators on panels are generally very cheap fixed voltage devices. You are better off purchasing a panel without a regulator. You then use this panel with a quality multi stage controller mounted close to the battery. That way you will get the best charge and thus the best value from your panel.

PeterD · Guru

Gus1949 wrote:
I think we will need a second controller in the front boot, which will but it within 200mm of the batteries.
Gus

You do not need a second controller. You say that your controller is mounted a long way from the battery, that's not good. Remove the controller and mount it where you are considering mounting your proposed controller. Feed both panels into it. You simply join the cables left unconnected when you relocate you controller, use screw clamps or crimp connectors and then tape over the join.

You are far better off having any cable losses between the panel and the controller than after the controller. The controller sees a truer voltage value of the battery that way.

Gus1949 · Senior Member

Thank you for your advice PeterD, I will explore the option to move the regulator and ditch the reg. on the solar panel.

Gus.

wasn_me · Guru

wasn_me wrote:
PeterD wrote:
Am I correct in assuming you would bypass or remove the regulator on the portable panel with this set up?
You should never have two regulators in series, you will loose too much potential power. The regulators on panels are generally very cheap fixed voltage devices. You are better off purchasing a panel without a regulator. You then use this panel with a quality multi stage controller mounted close to the battery. That way you will get the best charge and thus the best value from your panel.

Thanks for the reply Peter, I have an 80 watt panel on the roof of a pop top, running through a PR1515 to the battery. I was thinking of adding a portable panel, but have decided to go with another panel on the roof. I will have to look into stronger struts. I spend very little time at the van, so I don't think portable is the best option for me.

Cheers Pete

WAssa41 · Senior Member

You can use a DC to DC charger. CTEC D250S (smart Alternator) is designed to handle solar, wind generator and you car alternator and for my money is the best way to go. Have a look on E-Bay and read up on how it handles the alternator.

Regards,

Wassa

Palms · Newbie

I appreciate this is an old topic and I think my answer is covered in an chat in 2014 however best to check. Would appreciate confirmation. I have 200 watts of solar panels on the caravan roof, wired to a 30Amp regulator direct to the batteries in my Jayco. I want to occasionally add a portable solar panel with 160 watt. Total is 360 watts which is within the capacity of the 30 amp regulator. I have been told to bypass the MPPT regulator attached to the portable panels when attaching the portable panel to the van as it is not wise to have 2 regulators feeding into the caravan batteries. When using the portable panels to charge the boat or the car or whatever reconnect the MPPT regulator attached to the portable panels. I am getting conflicting advice including a statement that if I bypass the regulator attached to the panels it will void the warranty. Some say no problem if they are both MPPT Regulators, others say whatever you do don't connect 2 regulators. Can any one with the appropriate knowledge confirm that I need to modify the portable panel to bypass the the panel regulator when using it to add power to the caravan. Rod

Whenarewethere · Guru

It will be ok, but it is running at its limit so make sure it is well ventilated. I added additional heat sinks to my controller.

The roof top panels will only put out their rated output when the sun is directly overhead. So most of the day they will only be producing a percentage.

The portable you can keep turning over the day.

Sticking in an amp meter is really worthwhile. Simply to keep an eye on things in general.

Jaahn · Guru

Palms wrote:
I appreciate this is an old topic and I think my answer is covered in an chat in 2014 however best to check. Would appreciate confirmation. I have 200 watts of solar panels on the caravan roof, wired to a 30Amp regulator direct to the batteries in my Jayco. I want to occasionally add a portable solar panel with 160 watt. Total is 360 watts which is within the capacity of the 30 amp regulator. I have been told to bypass the MPPT regulator attached to the portable panels when attaching the portable panel to the van as it is not wise to have 2 regulators feeding into the caravan batteries. When using the portable panels to charge the boat or the car or whatever reconnect the MPPT regulator attached to the portable panels. I am getting conflicting advice including a statement that if I bypass the regulator attached to the panels it will void the warranty. Some say no problem if they are both MPPT Regulators, others say whatever you do don't connect 2 regulators. Can any one with the appropriate knowledge confirm that I need to modify the portable panel to bypass the the panel regulator when using it to add power to the caravan. Rod
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Hi Rod smile

Old threads never die !!

You should not use one regulator feeding into another. But you can use two simple regs in parallel. That might not be recommended but in practice works OK. In the initial bulk charge phase it causes no problem but may not be optimum. hmm The reg is better at the battery and portable panel wires are usually very small too.

I would seriously doubt that the reg on a portable panel will actually be MPPT anyway. Most likely to be a rebadged PWM reg like most of the cheap ones commonly are. It is an industry scourge that cheap MPPT regs are all fakes. disbelief

I usually say just buy a normal panel of what ever size and buy the wiring yourself. Do a better job cheaper. Just get a suitable panel with max power of around 18V.

Jaahn

Palms · Newbie

Excellent, thank you Jaahn. Good information

PeterD · Guru

WAssa41 wrote:
You can use a DC to DC charger. CTEC D250S (smart Alternator) is designed to handle solar, wind generator and you car alternator and for my money is the best way to go. Have a look on E-Bay and read up on how it handles the alternator.

Sorry, I missed this reply, my diaries indicate I was on the move after my last reply and I must have missed this one.

To simply call the DS250 a DC-DC charger is putting it down. It is far more than a simple DC-DC controller. That shows the futility of taking notice of evilbay. You should always go to the manufacturers' web site. Have a look at The CTEK 20A OFF GRID CHARGING SYSTEM. Watch the video presentations.

The unit can be uses as a DC-DC charger when the alternator input is connected to the tugs electrical system. It can be used as Solar charger when a solar panel is connected to the appropriate input, it is not acting as a DC-DC charger when that is happening. It also charges the tugs battery when there is solar input from the panels and the house battery is full

oldbloke · Guru

oldbobsbus wrote:
IF the panel has a built in regulator then that would work but if it doesn't then you would need to send the power through a regulator before the battery as I have seen 12v solar panels putting out 29v..
If I was doing it either way I would wire in an Anderson plug using 6 B&S cable to a convenient place on the van and then fit the end of the panel lead with an Anderson plug..

I have an Anderson plug that charges the battery from the car, like most.

I just plug my portable 120w into that. It works. Is it great, not sure but it does charge the battery as well as the one on the roof.

Yes you could make use of the 12 pin plug.

But I think fitting an Anderson plug direct to batt is your easiest and workable option. As mentioned good cable and just fit the Anderson plug where its convenient. If its not up to speed you can look at more efficient and costly options later.