Solar Panel Controller Connection

[keynsham1]

This might be a daft question but here goes anyway I have just finished rewiring the whole of the 'camper' part of my T25 during it's refurbishment. I now suddenly have the urge to be able to use a portable solar panel, more as a fun extra really! I have a leisure battery with a positive and negative lead going directly to a fuse box. connected to this fuse box are all my 12v accessories such as lights etc. In all the wiring diagrams I have seen for solar panel chargers, the connections for the controller go straight to the battery and then wires from the battery go to the fuse box, but is there any reason why I cannot connect the solar charger wires directly to the fuse box? It seems to make no difference as far as I can see and the solar controller wires have a direct connection to the fusebox anyway via the battery connections? It would make life very much easier as the solar controller will be right next to the fusebox! Obviously some suitable fusing would be required too for the controller leads. The lead from the leisure battery is already fused of course.



 

[Stesaw]

Id put fuses or trip/breakers on the positives from the controller to battery and battery to fusebox so you can isolate it if need be and when you aren't using it. As you're using a portable solar panel an isolation switch probably isn't needed from the panel to the controller.

When I redid my wiring stuff recently I've fitted two 30amp breakers on the positives so I can isolate the battery when I want to work on the stuff. As my panel is on the roof I also fitted an isolation switch in the solar panel positive before the controller.

As for the grounds, all my grounds are on the body of the van aside from the controller wiring which goes to the positive and negative battery terminals.

I'll be adding a better fusebox with common ground and positive to tidy up the wiring. Less wires the better

[TONYT25T25]

I have a small solar panel which i put in place wherever the sun shines on, my leisure battery is also connected via a split charger to the main system so it is charged when the engine runs. Standard fit I believe, the solar panel is not permanantly connected as a result of this otherwise it would damage the panel or controller I would imagine when the engine is running.

[Oldiebut goodie]

I have a small solar panel which i put in place wherever the sun shines on, my leisure battery is also connected via a split charger to the main system so it is charged when the engine runs. Standard fit I believe, the solar panel is not permanantly connected as a result of this otherwise it would damage the panel or controller I would imagine when the engine is running.

Yours will be the only panel that is damaged by the engine running then! My T6 has a 180 Amp smart alternator but has never caused any such problem.
I just use MC4 connectors then I can patch an external battery charger in if the need ever arises or as a means of isolation if that is needed.
Sometimes people overthink the situation.
On my old van I connected the solar panel to the vehicle battery and let a VSR take care of the leisure charging, my reasoning being that I preferred to be able to start the van rather than have electrics working in the back.
 

[TONYT25T25]

Whatever, I am still not going to leave the solar panel connected to the leisure battery via the control panel when the engine is running.

[Mocki]

My panels are permanently connected via my solar controller , my alternator charges when the engine is running and I can charge via mains when it’s parked under cover , no damage to anything has ever happened in the last 8 or more years I have had a solar panel(s)

[TONYT25T25]

I must be missing something somehow, I only have a basic setup, enough voltage/supply to use for internal lighting, water pump, phone charging and the onboard radio cd player from the leisure battery.  Just makes me unsure about having two power charging sources feeding one battery at the same time, although it would make it easier instead of having to disconnect the solar panel when underway so to speak.  The connection to the solar panel is via quick release clips so no great hindrance.

[Oldiebut goodie]

Whatever, I am still not going to leave the solar panel connected to the leisure battery via the control panel when the engine is running.

What do think is going to happen to yours that doesn't happen on everybody else's solar setup? Why would you be singled out for fire and brimstone and drawing the wrath of the gods down upon you?
I can't understand your reasoning - can anyone else?

[TONYT25T25]

Not really, just looking for a sensible response to a reasonable query, as previously posted, the connection of two separate power supplies/sources to one battery at the same time made me wonder that something in the system would be overcharged/damaged as a result.  

[Mocki]

Tony , they are called transistors and diodes , they are basically one way valves and taps they stop the elastic trickery going the wrong way .

You don’t unplumb your toilet before you empty the bath and nothing bad happens .

[TONYT25T25]

Thanks, it will sink in eventually, important point is, if I forget to disconnect the solar panel and controller from the leisure battery and drive off then all will be ok.  

[Mocki]

yes!

[Forden341]

Just to freak you out Tony.

I have a Karmann Gipsy, the dual leisure batteries are connected to a 330w solar panel via a controller and a mains charger when on hookup, once I started the engine and engaged the split charge relay so all 3 at the same time. Guess what happened…….

The batteries got charged!
All of them are voltage sensitive and won’t allow overcharging or back feeding.

[TONYT25T25]

Thanks, thought there was going to be a different result then, anyway I am feeling a bit guilty about hijacking this post from the originator "keynsham1", but thanks for inputs from all, taken onboard.  

[airheadboxer]

This link is pretty good on the subject and covers/summarises some of the questions and concerns gone over above:
 Can I Connect a Solar Panel Directly To a Battery