Portable solar panel to keep leisure battery topped up in storage

[Cali4nia-Dream]

I cant spot anything that quite answers my question on the forum but if I've missed it please point me to the solution.

I have a small solar panel that we used in the old MH to keep the battery topped up when not used for several weeks.The model was recommend by local garage who used it on other customers with vehicles stored outside and not used a great deal. It seemed to cure the problem of batteries going flat, and being placed on the dash it was protected from the elements.

We have to replace the garage as too small for Cali and don't want to keep her on the street. Getting electrics installed in new carport at end of the garden is messy in terms of cabling and electrical regs certification.
My thoughts are put the solar panel on carport roof and connect it to the leisure battery, just to keep it/them topped up.

How easy is it to get a connection onto the leisure battery of a T6 Ocean?
Are the two batteries connected such that putting the charger onto one will charge both?
Would this interfere with the canbus? or the alarm system?

I am aware of the need for voltage regulators to prevent over-charging, but if the basics of this can't be done i.e connecting to the battery in a quick and easy manner then this idea is a non starter

Any feedback/comments appreciated

Chris

 

[Hotel California]

Are you sure you took a look at the existing treads regaring solar panels.
Some have put thiere reports on here (with pictures) of the installing of panels even some did DIY ...
Have you read them?

 

[Loz]

A modest solar panel, simple charge controller, some flat twin cable(good speaker cable) and a cigarette plug can be plugged into an existing 12v outlet as these are permanently on. Then feed the cable either through a sliding window or through the door and close it on the cable it won't get crushed as it will be held in place by the door seal.

Simples!

 

[WelshGas]

A modest solar panel, simple charge controller, some flat twin cable(good speaker cable) and a cigarette plug can be plugged into an existing 12v outlet as these are permanently on. Then feed the cable either through a sliding window or through the door and close it on the cable it won't get crushed as it will be held in place by the door seal.

Simples!

Just have to check that the 12v socket you use is connected to the battery you wish to charge. Eg: Engine battery - 12v socket in pull out dashboard tray. Leisure battery - Kitchen Unit/Boot or cupholder on seat base near sliding door rear.

But some sockets seem to have been wired to different batteries so check first.

Otherwise, if it is just the Engine Battery then use clips to attach to engine battery directly.

 

[briwy]

T5 manual specifically states no external power supplies should be plugged into the sockets so you need to make a direct plug and socket connection to the leisure battery.
I'm assuming the T6 is the same.

 

[MattBW]

Yeah I agree with briwy, although I have used a charger in my rear socket after reading on here you shouldn't I haven't done since. Worth checking in the manual.


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[Bramco]

I wonder why they say you shouldn't. Assuming you are connecting the panels through a charger then I'm not sure what harm it could cause. Maybe it's just one of those blanket safety warnings. Making the direct connection to the leisure battery is surely the same as connecting through one of the sockets.

 

[briwy]

I can't see why either unless it's perhaps the fact that the wiring for the sockets goes through the control panel somehow and it may damage it. Without a detailed wiring diagram it's hard to know

 

[viking]

I wonder why they say you shouldn't. Assuming you are connecting the panels through a charger then I'm not sure what harm it could cause. Maybe it's just one of those blanket safety warnings. Making the direct connection to the leisure battery is surely the same as connecting through one of the sockets.

I'm no electrician but somebody tell me what's wrong with this idea. You get your desired size solar panel and choose it's location fix the required length of cable and connect to the same socket type as required for the electric hook up and plug it into the vans EHU point.

 

[Loz]

I have done this one 2 previous overland vehicles with no issues. The power generated by the solar is way less than the fused rating of the cigar sockets so as long as it's permanently connected to the battery you want to charge there will be no issue.

 

[WelshGas]

I'm no electrician but somebody tell me what's wrong with this idea. You get your desired size solar panel and choose it's location fix the required length of cable and connect to the same socket type as required for the electric hook up and plug it into the vans EHU point.

The vehicle EHU socket connects to a 240v mains circuit that provides mains power to the Mains 3 pin socket on the kitchen unit and Mains power to the built in Battery Charger. It does not connect to the Leisure Batteries.
A solar panel produces 12 or 24v output, so has to be connected directly to a 12 or 24v battery.

 

[briwy]

I'm no electrician but somebody tell me what's wrong with this idea. You get your desired size solar panel and choose it's location fix the required length of cable and connect to the same socket type as required for the electric hook up and plug it into the vans EHU point.

Because the hook up tales 220v AC mains in not the nominal 12-15vv DC from a solar panel.

Cross posted

 

[WelshGas]

I have done this one 2 previous overland vehicles with no issues. The power generated by the solar is way less than the fused rating of the cigar sockets so as long as it's permanently connected to the battery you want to charge there will be no issue.

I think the problem may be that the 12v sockets on the California are not just connected via a fuse to the Leisure Batteries. I think, I could be wrong, there are some electronics involving the Control Panel that monitor voltages etc: and also control the Fridge and Parking Heater so that the Leisure Batteries are not over stressed by their operation.
With a new Control Panel costing £700 + to replace then I will leave it to someone else to test it out.
My panel is wired directly to the Leisure Battery.

 

[Cali4nia-Dream]

Thanks for all the feedback and comments.
To summarise;

There is some circuitry monitoring battery voltages so back-feeeding through cigarette sockets could damage the circuitry/control panel. Therefore even connecting directly to the battery with one of these portable solar panel devices could damage the circuitry unless the battery was disconnected, but that is not easy and could cause other problems.
Its a shame as it worked so simply on the older MH but this idea stops here.

 

[WelshGas]

Thanks for all the feedback and comments.
To summarise;

There is some circuitry monitoring battery voltages so back-feeeding through cigarette sockets could damage the circuitry/control panel. Therefore even connecting directly to the battery with one of these portable solar panel devices could damage the circuitry unless the battery was disconnected, but that is not easy and could cause other problems.
Its a shame as it worked so simply on the older MH but this idea stops here.

Not quit correct. Connect the Solar Panel directly to the Leisure or Engine Battery terminals is OK. You DO NOT have to disconnect the battery from the vehicle.
Connecting via one of the 12v sockets is contrary to VW's advice and might be problematic.

If you want to plug a Solar Panel in and do not want a permenant connection then you have 2 possibilities.
1. Use crocodile clips onto the battery terminals.
2. Wire in a separate 12v socket with a fused link directly to the Leisure Battery. Ideal place would be the panel covering the rear leisure battery at the base of the wardrobe.( look from the open tailgate to the L side ). Or any other place you fancy. This will bypass all the California electronics and avoid any possible problems.
My Solar Panel is wired permanently to my rear Leisure Battery as it is mounted on the roof.

 

[Bramco]

This could be another case of Beach vs SE/Ocean. The beach doesn't have a control panel with battery level indication, no fridge, no inverter. It's 9:30 so I'm not going out to get my manual. Anyone else fancy braving the rain to go check if the Beach doesn't have the warning?

 

[Loz]

Thanks for all the feedback and comments.
To summarise;

There is some circuitry monitoring battery voltages so back-feeeding through cigarette sockets could damage the circuitry/control panel. Therefore even connecting directly to the battery with one of these portable solar panel devices could damage the circuitry unless the battery was disconnected, but that is not easy and could cause other problems.
Its a shame as it worked so simply on the older MH but this idea stops here.

Battery monitoring is achieved with an earth shunt. Charging through the circuits actually works with the system and allows it to correctly monitor the charge going back into the battery, connecting directly to the battery circumvents the battery monitor and will give you a false measure of battery state.
Either will work, there is no risk to circuitry as long as everything is fused correctly.

 

[briwy]

Well no one seems to know for sure why VW state it's a no no. Some say it's OK, some say not.
Personally I don't see why you would risk it especially as it's easy enough to put a plug and socket direct to the leisure battery.
One things for sure, if something goes wrong and your van is in warranty then VW will do their best to wriggle out of it if you have done something the manual tells you not to.

 

[kave]

So, when this is cleared up, anyone with experience of portable solar chargers?

 

[Loz]

A manufacturer will never recommend anything as they are just covering their warranty arses.
If there was enough call for these systems that manufacturer would seek a certificate of no objection from VW.
But as far as VW are concerned they already have a perfectly good solution in what they have supplied.

I have built a few systems in my time and if .I was doing it today on the Cali, I would install one of Roger's for the leisure side.

If I just wanted a temporary plug in solution as requested by th OP then I would install a dedicated socket wired into a spare fuseway.
There is no problem with a plug in solution taking into account the following;
1. Is the socket wired to the side of the vehicle you want to charge? (Leisure or starting)
2. Is the socket permanently live, sockets normally supplied by the starter side are normally switched and only connected when the key is in the ACC position.
3. The cable you plug in will have a male end that would be live if the panel is generating so you should include a switch in the cable.

There are some nice little kits you could put together for this.

 

[campandfly]

A modest solar panel, simple charge controller, some flat twin cable(good speaker cable) and a cigarette plug can be plugged into an existing 12v outlet as these are permanently on. Then feed the cable either through a sliding window or through the door and close it on the cable it won't get crushed as it will be held in place by the door seal.

Simples!

Hi Loz
I love the simplicity of this answer and solution. I am really keen to hook up some solar say with a 100w panel and an MPPT controller.
Do I understand your post correctly? I can just plug into either the Dash 12v Cigarette lighter socket for the starter battery or one of the rear (lounge area) 12v Cigarette lighter sockets to charge the leisure batteries.

Right now I am too chicken to wire anything permanent in till I understand things more fully and also want the panel available for other projects.
Thank you

 

[jts46]

Hi Loz
I love the simplicity of this answer and solution. I am really keen to hook up some solar say with a 100w panel and an MPPT controller.
Do I understand your post correctly? I can just plug into either the Dash 12v Cigarette lighter socket for the starter battery or one of the rear (lounge area) 12v Cigarette lighter sockets to charge the leisure batteries.

Right now I am too chicken to wire anything permanent in till I understand things more fully and also want the panel available for other projects.
Thank you

Yes, that is what i did 4 yrs ago

 

[campandfly]

Yes, that is what i did 4 yrs ago

What about polarity? Not being too savvy with electrics. I want to make sure I have the male cigarette plug wired correctly.

 

[Loz]

What about polarity? Not being too savvy with electrics. I want to make sure I have the male cigarette plug wired correctly.

The centre pin is positive.