I have recently bought a 100w panel with a 10amp controller. I bought some cables to go with it to attach from the controller to the battery using crocodile clips. This works and when connected shows and increase in volts compared to when the panels not connected but the cables aren't quite long enough as only 2mtr long which only enables me to lean the panel against the front of the van rather than been able to turn it towards the sun. Other than buying some longer ones off the internet is there any other places to get this cable from or is there even any other household style cable that can be used on the market. The ones I currently have attached are 4mm solar cable (not sure of the exact name). Totally confused with all the DC and volt stuff etc. Any help would be greatful
Although I'm no expert I guess the solar reference means that the cable is UV resistant, I would take the cable to an electrical wholesalers and show it them. My 80w panel charges the battery perfectly, we had 2 wks last summer with no ehu, watching tv every night and charging phones etc.
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Is the issue, that the supplied cable has "special" plugs fitted?
If that is not the case then many other cables are well suited to join a freestanding panel to the controller.
I actually use my mains EHU cables as I carry these [a long and short one] anyway and they have suitably thick copper conductors so voltage loss is minimal. In my case I have made adaptors so I simply insert the EHU cable, if I need to move the panel out further than the cable on it allows. The adaptors use the earth and neutral together as a single core, with the positive used for the return.
That might be complicating things, but you can buy this cable at DIY places and make up your own lead; this cable will be sold as 2.5 mm square, cored cable. The fact it is sold for AC and we use it for DC is irrelevant, what in our case is important is the copper cores are thick, so we lose little of what we gain from the solar panel.
Caravan sites are full of curious children and helpful strangers. The Use of EHU cables introduces the possibility that one day your battery or solar panel may get connectef to the mains in error!
Quote: Originally posted by Jesscar on 23/3/2015Caravan sites are full of curious children and helpful strangers. The Use of EHU cables introduces the possibility that one day your battery or solar panel may get connectef to the mains in error!
I will risk it. It has not been an issue in 13 years sofar. It is of course not deployed on sites that have EHUs, I don't need the solar system there, so the risk I would put at zero.
The plug end of my cable would only fry the solar panel, and it feeding to the panel ought to give even the dumbest "helper" a hint. Do people go around rallies uncoupling leads to deploy them elsewhere?
Doing as I do I don't need to carry yet another heavy current cable, suits me ideally.
It is better to have the controller close to the battery. Don't ask me why I can't remember When I had free standing panel. I use the cable from an old flymo lawn mover and a yellow 110v socket and plug (similar but not the same as the ehu plug) not the most professional setup but it did work and allowed me to move the panel all around the caravan.
Why not just use another length of the 4mm cable, I've just bought a length which I intend to enter the van where the 230volt supply enters connected with an anderson connection.
Then to the controller back through the battery box to the battery.
I searched on the forum and it's well explained.
Going to buy a semi ridged panel as my van roof is not strong enough for a fixed panel. Guess I can put it up on the roof out of the way or position it on the ground.
Quote: Originally posted by boff on 23/3/2015
It is better to have the controller close to the battery. Don't ask me why I can't remember
Two reasons are:
1)Decent controllers have battery temperature, voltage compensation, frequently in the unit, so it needs to be at same temperature to the battery.
2)So the battery sees the controlled voltages not voltages with the losses from current in the cables between the controller and battery.
Just shows the sutupidity of some commercial panels sold with controllers glued to the back of panels as not only these two aspects are not addressed but solar panels get hot!
A good reason not to carry a cable for the solar system is that a decent current carrying one is quite heavy and takes space, so why I use either, or both my 10 or 15 metre EHU cables. I believe in minimising caravanning clutter.
Hi JTQU, sorry my post was not intended to criticise what you're doing. Really my caution was intended for other readers, who may be in different situations, maybe with friends or relatives helping with setup. Their results could be quite different.
Thanks for your advice. I'm going to make a cable up from an old why cable in that case rather than buying yet more 4mm solar panel cables to achieve the longer cables. Just a little unsure about my controller now as it is secured on the back of the panel.
Just one last question I read on the instructions to connect the battery to the controller before the panel, the only problem I have is that the cables secure to the controller using little screws to hold them in and would need to keep removing a cable to power it down/up everytime I wanted to use it. The only other option I can think of is to find something to cover the front of the panel up while it's connected together then it isn't taking in any power. What's peoples views on this.
As your controller is mounted on the panel, then surely it is by design connected to the panel before you connect it to the battery? So it seems it withstands that abuse every time it is connected and every time the panel sees light when not connected to the battery?
There are various "polarised" plug & socket connectors you can buy from the likes of Maplins for DC.
Whilst the cable used with it is light, it is up to carrying the current, and as hopefully only this short length of "restrictive" cable will be used voltage losses will not be an issue.
then i would use some 10 AWG silicone cable or artic grade to make the extension up with the plugs to match each end...
The reason most portable panels have the charge controller on the panel is safety even small systems can hold a few hundred volts on the panel to charge controller wiring Untitled by monty1995, on Flickr
but then again im a dab hand with a soldering iron / pencil blow torch.....
Quote: Originally posted by andy monty on 26/3/2015
The reason most portable panels have the charge controller on the panel is safety even small systems can hold a few hundred volts on the panel to charge controller wiring
No there is not a few hundred volts, you are miss understanding that panels labeling.
That panel itself can only put out 21.6 Volts DC, it can only safely be used in an array of panels wired in series that has up to a total system 600 volts ,ie 28 panels wired in series!
So unless you are thinking of having a large number multi panel array you can stop worrying about safety.