Jump to content

Best Way Of Connecting Portable Solar Panel


srw8553
 Share

Recommended Posts

I've decided to buy a 50W portable solar panel for the caravan. I'm aware of the importance of cable size and length to reduce losses but have two main queries.

 

Are the any advantages/disadvantages of fitting the charge controller onto or near the panel rather than near the connection point to the battery?

 

In view of the potential losses due to cable length/size how important is the method of connecting to the battery terminals? I see many portable solar kits use crocodile clips but would a better method of securing the cables to the battery reduce losses?

 

Thanks for any help.

Volvo XC70 towing a Coachman VIP 520

The older I get the better I was

Link to comment
Share on other sites

I can't comment on your portable panel other than we just attach ours direct to the battery (ours is only 14 watts and has a built in charge controller). However we just had panels installed at home and we talking generally about routing the cables and the electrician told us that power loss from overlong cabling is negligible.

The traveller sees what he sees, the tourist sees what he has come to see (GK Chesterton)

 

There's no such thing as bad weather, only the wrong equipment (Alfred Wainwright)

Link to comment
Share on other sites

The controller should be close to the battery as it needs to monitor the battery volts accurately. My controller also has a short temperature monitoring lead to help calculate the charge.

 

House solar panels I believe operate at a much higher voltage series cct), so volt drop is not as important as 12V systems.

To connect I use the standard waterproof connectors, can't remember the reference, which you can find on ebay. Just looked up

MC4 connectors

e. g. Oops, paste not worked, look for MC4 in eBay.

My lead from the panel to the caravan is about 3 meters

Chris in Warwickshire, Elddis Odyssey 482 (2008), Mitsubishi Outlander diesel, 2017

Link to comment
Share on other sites

You are also better off having the leads carrying the voltage from the panel to the controller long and those from the controller to the battery short as the slightly higher voltage from the panel (17 to 30v) will not be as affected by resistance losses.

Enjoy every minute of every day. It doesn't last nearly as long as you'd like, and there's no guarantee of coming this way again.

Link to comment
Share on other sites

I have always connected my solar panels directly screwed to the battery terminals via a 'fly' lead. The 'fly' lead is complete with a waterproof socket and sits neatly inside the battery box until connected to the solar panel which has the corresponding waterproof plug.

 

My panels have always been fitted with the controller attached to the back of them. Although I have been told that this is not the ideal place to site the controller I have never had any problems over the years.

 

Bill

Link to comment
Share on other sites

This thread will help I think : Connecting Solar Panel to Battery

 

Ours is very easy to plug in when required.

2007 Bailey Series 5 Senator Arizona (4 berth, rear bathroom, side dinette) towed by a 57 Kia Sorento XS Auto with Kumho KL17 tyres, Reich Mover, Kampa Rally 390, Caravan Tyres : GT Radial Maxmiler CX 185/80 R14 102R.

 

Link to comment
Share on other sites

Thanks for the replies. It seems the best place for the controller is as near the battery as possible so I'll look at making up some fly leads so it will fit in the compartment next to the battery where the EHU socket is.

 

That just leaves the best method of securing the leads to the battery. I can see the benefit of fixing a plug and socket system to the battery but I was interested in knowing whether such a system would have lower losses than crocodile clips. Does anyone know?

 

Also there appears to be some safety benefit of installing an inline fuse but will this increase losses?

 

. ...... or doesn't any of this matter? :)

 

Thanks

Volvo XC70 towing a Coachman VIP 520

The older I get the better I was

Link to comment
Share on other sites

Losses through a fuse or from a set of quality croc clips would be negligible in this scenario, imho. 150A supplying an inverter is a very different scenario and I've used 50mm2 cable, properly crimp-terminated and bolted onto the terminals!

 

All DC circuits should be fused on the positive line. This is more to prevent the nasty impacts from cable shorting rather than the equipment itself malfunctioning. You fuse for the circuit, including the connecting cable, not just for the device being powered i. e. if the cable is rated at 5A, you must fuse the circuit at or lower than this (to avoid a fire risk).

Link to comment
Share on other sites

I use 6mm cable from the controller to the battery. The battery is a Numex which has a pair of auxiliary connections which take ring connectors and wing nuts. Without these extra connectors one could use the bolt for the normal battery clamp.

In the positive lead I have put a blade type inline fuse for safety and also into which I can plug the incredibly useful Maplin "Automotive current tester" so I can monitor the actual amps into the battery.

The fuse is handy also as I can remove it when not using solar power (e. g. storage) to stop any leakage current back to the controllers electronics.

post-13194-0-15050200-1391528146_thumb.jpg

Edited by ChrisUK

Chris in Warwickshire, Elddis Odyssey 482 (2008), Mitsubishi Outlander diesel, 2017

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...