help using solar panels

What model Ctek? What type of batteries (wet, AGM, gel..?) and roughly how big are they (100Ah is about the 30x16x20cm) What make and model "solar booster" (ie regulator).

What sort of fridge? 12V/240V? Can it run on gas, or is it a compressor type?

Happy to help, but we need more detail! The setup sounds good and thorough but may be nonstandard.

Suggest don't try the solar panels till this is figured out - you could damage a battery fairly easily with an unregulated 120W panel.

You might find our blog Electricity for Camping a useful read.

Cheers

John

I would say 99% of the time you want the Regulator (solar booster?) switch in the 14.4V setting.

14.7V is good for reconditioning wet cell batteries but is to high for AGM batteries.

Assuming the CTEK is for charging from 240V, when you have access to mains, or generator power, no effect on your solar setup.

There are indeed other variables so its a little hard to answer exactly but hopefully this helps.

Depending on your vehicle setup, (do you have dual batteries in the vehicle?) and the type of isolator installed, if you have dual batteries in the vehicle...... there may be no point, but also no harm in leaving the anderson plug connecting your vehicle's power to the camper trailer when hooking the solar power up to the camper trailer.

The 4way switch in the camper trailer... you need to look at how it is wired. All functions may not be in use anyways, but for the sake of it you should look if possible at how it is wired.

I doubt it has been wired this way, but it could have been...

You said you have two aux batteries in the camper trailer, they may be connected in parallel via this switch, or not... If they are connected independently, i would guess you therefor have the ability to switch between OFF, Aux battery 1 only, Aux battery 2 only and Both Aux batteries together.

(BUT i think it is more likely to be wired like this:)

Since it has been labled "Car battery, Trailer battery" etc. I would assume this switch actually allows you to isolate the Camper trailer from the vehicle via the switch therefor you do not need to disconnect the anderson plug (for the car). Basically that positive wire goes through to this switch, so if you have the switch set on both, it allow's both the car and camper trailer to charge together ie. when the engine is running.

(But this is another little can of worms, you see over the length of wire between you vehicles alternator and you camper trailers batteries there will be substantial voltage drop, so you will most likely find that your vehicles alternator is not able to charge the camper trailer batteries when the engine is running, for this, you will need a DC-DC charger which will effectively BOOST the volts from the alternator and allow you to charge the camper trailer batteries when driving)

But, when stopped, if the switch is set on BOTH you could potentially also drain your vehicles battery(s) via. the fridge in the camper trailer etc. So, when stopped you should switch it over to Trailer or unplug the anderson plug, does the same thing to isolate your car's battery(s?)

If this switch is wired as above, (would make more sense then wiring the 2 camper trailer batteries independently through it but you never know...) then you have the ability to, leave the anderson plug connected to your vehicle and plug in the solar panel to the another anderson plug, and charge the whole lot together, or just the camper trailer batteries. Potentially even direct the charge to the Vehicle only, Trailer only or Both...

Again, depending on your vehicle setup, (do you have dual batteries in the vehicle, and anything connected to the aux battery in the vehicle - car fridge, lighting, stereo etc?) If so, then you may wish to charge the vehicles aux battery with the camper trailers batteries... So the 4 way switch in the camper trailer should be set to BOTH. But if there is nothing draining power from the vehicle, or no vehicle aux battery simply switch the 4 way switch to Trailer when you connect the solar panel anderson plug to the circuit.

Hope this makes sense. Kinda just thinking out aloud, happy to explain things in a little more detail but hopefully this gives you an idea how things should work.

Travis.

Hi Travis,

Thankyou for your helpful advice ... I'll spend a bit of time trying to digest it, and pass it on to my husband (he is simply too busy to spend time researching so tis up to me!).

One thing I can clarify - we only have one battery in the car .... two batteries in the trailer. I am pretty sure they are gel .... but will be checking this as soon as we have some spare moments .... plus the Ctek model and solar booster ..... will also try to trace the wiring so that we can give a better picture of our setup.

I'll be back with more info ........

cheers,

Lenita

Hi Lenita,

Sorry to be slow getting back to you, but Travis has provided a very good and comprehensive reply. We both face the problem of trying to decide the function/s being performed by your gear and guessing just how it is most likely connected up. The Ctek for example may be for charging from the mains, or could be a dc-dc type for increasing the charge from the vehicle to the "house" batteries as Travis describes, or could be doing that and also managing solar charging - depends on the model. Likewise the switching could be intended for several different uses depending on whether the batteries are connected in parallel or arranged so that they can be used independently.

I think it may be time to suggest asking a COMPETENT electrical person to look at it and produce a diagram of what is doing what and going where.

Just how long you can run the fridge will depend on battery size. According to the specs, your fridge will probably call for about 50 amphours per day - very dependent on how you use it. IF your two batteries are each about the size I mentioned, and in reasonable condition, they should each run the fridge for one day without any charging.

Your solar panels should deliver about 7 amps in strong sunlight, maybe a little more depending on the type of controller. So - in 7 hours they should harvest enough to run the fridge for 24 hours. How to get them working? Depends on your setup, so we come back to that competent person tracing out what's going where.

I would use the lower voltage setting (14.4V) on the "solar booster" though the "solar booster" is itself a mystery box whose function needs to be determined.

Afraid that's not a lot of help, but I think there are too many unknowns to provide the answers with any certainty.

Cheers

John

Hi John,

Thankyou for your help. We will be taking the car to an auto electrician within the next few days to install an anderson plug ...... we have decided to tow the trailer to his workshop at the same time for a 'looksee' & hopefully some assistance to solve some of the 'mysteries'!

Do we need to know anything re the installation of the anderson plug? Or is that straightforward (please say it is!!!!) .........

Why does all this have to be so complicated??? I just want to 'plug and play'!!

Thankyou again,

avidcamper

okay .... I've taken photos of the electrics - hopefully that will tell a story. Now .. to attach them .... hmmmm - is there a way to do this?

Lenita,

At the bottom of the "reply" screen is a set of buttons - "preview", "submit", etc. One of these is "Insert Image" Click that and enter the details. You will need to navigate to each image on your computer, and give it a caption. Easy!

Cheers

John

Hi John,

Thankyou once again for your helpful advice re isolating the car battery - my husband will make sure he mentions this to the auto electrician when he drops the car off tomorrow to install the anderson plug.

Cheers,

Lenita

Hi John,

Thankyou so much for your patience & follow up on our electrical dilemmas!

First of all, that red switch in the camper boot is described very briefly in the camper information as an isolater switch .... whatever that means - I do wish we had been provided with better instructions & info! I guess that's what happens when purchasing second-hand goods .....

To answer your question regarding the solar panels - I am unsure as to whether they have been previously used, however I assume they must have been since they were sold with the camper. We bought it from a caravan dealer - I don't think he would have 'thrown them in' with the sale. The wiring etc. is all in place. In some ways, it would have been most beneficial to have been able to speak with the original owners .... the dealer really didn't seem to know more than to say 'plug the panels into that anderson plug there' ..... which has proved unsuccesful so far.

We may need to tow the camper to a service centre and have a qualified person look at it and advise how to use it correctly .... perhaps even book it in for a service - although everything seems to be in very good condition ..

I'll post any progress we make on this - hopefully we resolve it before we go away!

Cheers,

Lenita

Sorry to be such a pain, but we are still having issues with our folding solar panels. After doing more research, I realised that we have been inadvertently running the risk of damage to our batteries by plugging the solar panels into the anderson plug that should be plugged into the tow vehicle. This bypasses the solar charge controller (I think) - instead (I think) it is wired to the Ctek multi excess 2500 mounted in the trailer near the batteries. (The panels did begin charging - but we decided not to continue since we don't want to cause any damage).

We have been trying, unsuccessfully, to figure out how to get the solar panels to charge the batteries using the second anderson plug in the camper boot (which is apparently designated for solar) - but when we use this plug, the LED display on the back of the panels does not light up - a blue light should flash indicating that the panels are charging the batteries.

Would there be a switch somewhere that is escaping our attention??

Or should this be an automatic operation?

The caravan dealer told us to simply plug the panels in ..... but he didn't appear to know enough to answer our questions. (The camper is second-hand, so we don't know who installed the electrics, unfortunately ...).

The solar charge controller does not appear to have any make or model or serial number, so I can't obtain any info on its operation.

Our auto-electrician didn't feel confident enough to help with the solar side of things ....

We do need help with this - preferably an electrician who is experienced with battery chargers, solar panels ect ...... does anyone here know of such a (wonderful!) person who could help us unravel the mysteries of our camper trailer battery & charging setup?

Do we need to book it in for an unnecessary service somewhere in order to figure all this out?? (I say 'unnecessary' because it has already been serviced by the dealer we purchased it from ......).

Sorry for this long-winded and rather convoluted request for help .... I don't know how to explain all this properly ....

Please see my lilnk to some photos of the trailer batteries, chargers, plugs & dials in an earlier follow-up on this thread.

cheers,

avidcamper