Solar connection

S

Shadrack

Lifetime VIP Member
Messages
338
Location
West Wales
Vehicle
T6 Ocean 204
Hi to all,
I am about to instal a Victron MPPT 75/15 in readiness after I fit a couple of permanent 100w panels To my 2016 204. I have read and looked at many installations and diagrams, some wired a little different to others.
I plan to put an isolation trip between the panels and Victron.
I have a couple of queries on the battery connections.

I think I am correct in saying wiring direct to the rear leisure bat via a fuse is ok?

Also I plan to put a 2pole changeover switch on the battery output of the Victron (Break before make) the second output from this switch I want to connect to engine battery via a fuse. This I think, switching to this would be a just in case measure if I ever allowed the engine battery to become low.
Is the above ok? if so can I find suitable engine battery connections under the passenger seat?

Any advice would be helpful.

Thank you.
 
Hey Shadrack not sure if this helps, bit boring and long but hope it gives you some direction.

 
Hey Shadrack not sure if this helps, bit boring and long but hope it gives you some direction.

Hi Andy,
Thanks a lot, the guy has done a real neat job and I think I will follow most of his approach. Really useful to me.

I did also mention fitting an extra changeover switch to top the starter battery up but I have decided to ditch that idea when I think back over my 6 years of ownership without any starter battery problems.
However I did discover under the passenger seat a direct line to the starter battery on the split relay if anyone else was thinking to trickle the starter battery.

Once again Andy, thanks for taking the time to post. It is helpful to me and others I think.

Cheers
Shadrack.
 
Hi to all,
I am about to instal a Victron MPPT 75/15 in readiness after I fit a couple of permanent 100w panels To my 2016 204. I have read and looked at many installations and diagrams, some wired a little different to others.
I plan to put an isolation trip between the panels and Victron.
I have a couple of queries on the battery connections.

I think I am correct in saying wiring direct to the rear leisure bat via a fuse is ok?

Yes, with the caveat to use the chassis ground. Direct to the rear bat allows you to monitor the rear battery voltage independently of the front one which will give you an early indication of a problem.

Also I plan to put a 2pole changeover switch on the battery output of the Victron (Break before make) the second output from this switch I want to connect to engine battery via a fuse. This I think, switching to this would be a just in case measure if I ever allowed the engine battery to become low.
Is the above ok? if so can I find suitable engine battery connections under the passenger seat?

Any advice would be helpful.

Thank you.
All sounds 100% to me. Thoughts below:

A simple fuse is probably sufficient for the panels. You won't have the need to switch them off often (if ever)

There are various options to charge the main battery using what you have:
  • Load output on Victron using a diode and current limiting resistor. The Victron can be setup to switch on the load at (say) float voltage.
  • Permanent diode and current limiting resistor. Cheap and fits under the front seat.
A diode will introduce a voltage drop so won't get the starter battery to 100%.
 
Yes, with the caveat to use the chassis ground. Direct to the rear bat allows you to monitor the rear battery voltage independently of the front one which will give you an early indication of a problem.


All sounds 100% to me. Thoughts below:

A simple fuse is probably sufficient for the panels. You won't have the need to switch them off often (if ever)

There are various options to charge the main battery using what you have:
  • Load output on Victron using a diode and current limiting resistor. The Victron can be setup to switch on the load at (say) float voltage.
  • Permanent diode and current limiting resistor. Cheap and fits under the front seat.
A diode will introduce a voltage drop so won't get the starter battery to 100%.
Hi Yossarian,
Thanks for the input, yes I noticed the neutral to earth connection in the video, I was not sure of it’s relevance.

I like the idea of the diode and limiting resistor, you wouldn’t know the resistor value would you? if I do add that I think as you have suggested I would put a fuse on the Victron load output line and connect only when the starter battery charge need arises.

I think I will adopt the fuse idea between panels and Victron ta, I have seen some trip fuses used for ice connections etc that are quite small and will do the job.

Thank you again.
 
Hi Andy,
Thanks a lot, the guy has done a real neat job and I think I will follow most of his approach. Really useful to me.

I did also mention fitting an extra changeover switch to top the starter battery up but I have decided to ditch that idea when I think back over my 6 years of ownership without any starter battery problems.
However I did discover under the passenger seat a direct line to the starter battery on the split relay if anyone else was thinking to trickle the starter battery.

Once again Andy, thanks for taking the time to post. It is helpful to me and others I think.

Cheers
Shadrack.
no worries btw this is my you tube channel :p but glad it was of some use.
 
Back of the envelope:

Max voltage differential: 14.5 -11 = 3.5
Silicon diode voltage drop = 0.6
Desired current at say 1V diff = 2A

R = 0.5 Ohms

Current at 3V net differential = 6A
Power dissipated in resistor = 36 * 0.5 = 15W
Power dissipated in diode approx 0.7*6 = 4.2W

So a 10A silicon diode capable of getting rid of 5W and a 20W+ 0.5 Ohm resistor should do the job. A schottky would have better numbers (less heat) and charge your battery a bit higher.
 
Are you still getting only 50% shown on your bar graph?
i think its mainly that we dont get much sun at the moment so i only get around 2a during day, however it is enough to keep the leisure batteries topped up at 100% which is great to ensure the batteries don't get damaged. Will be good to see avg when we go to Europe in the summer or how it peforms in the UK in Summer i am hoping we avg c8a to 13a during the day which would be around 130ish Watts? i am deffo no expert but happy to share anything i have learned so far.
 
i think its mainly that we dont get much sun at the moment so i only get around 2a during day, however it is enough to keep the leisure batteries topped up at 100% which is great to ensure the batteries don't get damaged. Will be good to see avg when we go to Europe in the summer or how it peforms in the UK in Summer i am hoping we avg c8a to 13a during the day which would be around 130ish Watts? i am deffo no expert but happy to share anything i have learned so far.
Is the thing I illustrated still half blue half grey? If so you probably have a problem.

Screenshot_20221101-220841.png
 
01_Plan.JPG
This is how I wired mine .... works perfectly. The starter charging switch is only left on when I park up the van on the driveway for more than a few days - then all batteries are always kept at 100% .... you will notice if you have stop-go/recuperation with a smart alternator that after driving, the solar delivers more ... this is because the smart alternator and recuperation strategy tries to keep the batteries around 90% .. the solar then tops them up to 100% when you park up.

Some pics of the install ....

06_PanelCableRoutingExt.jpg09_MPPTandPanelCircuitBreaker.jpg
11_ArgofetPassengerSeatRunning.jpg
14_StarterBatteryChargingSwitch.jpg
 
View attachment 101307
This is how I wired mine .... works perfectly. The starter charging switch is only left on when I park up the van on the driveway for more than a few days - then all batteries are always kept at 100% .... you will notice if you have stop-go/recuperation with a smart alternator that after driving, the solar delivers more ... this is because the smart alternator and recuperation strategy tries to keep the batteries around 90% .. the solar then tops them up to 100% when you park up.

Some pics of the install ....

View attachment 101308View attachment 101309
View attachment 101311
View attachment 101310
This is a very nice setup, but I think you'd probably do it a bit differently if you did it from scratch?
 
Back of the envelope:

Max voltage differential: 14.5 -11 = 3.5
Silicon diode voltage drop = 0.6
Desired current at say 1V diff = 2A

R = 0.5 Ohms

Current at 3V net differential = 6A
Power dissipated in resistor = 36 * 0.5 = 15W
Power dissipated in diode approx 0.7*6 = 4.2W

So a 10A silicon diode capable of getting rid of 5W and a 20W+ 0.5 Ohm resistor should do the job. A schottky would have better numbers (less heat) and charge your battery a bit higher.
Hi Yossarian,
Thank you for information and taking the time to do calcs. I did not realise so much heat would be dissipated by the wire wound.
thank you
 
This is a very nice setup, but I think you'd probably do it a bit differently if you did it from scratch?
Must admit ... I didn't count on the solar fighting the recuperation strategy which is trying to maintain about 90% charge on all batteries, while the solar is trying for 100% ... The solar comes on full when the smart alternator switches off and tries to run all electrical loads.
 
View attachment 101307
This is how I wired mine .... works perfectly. The starter charging switch is only left on when I park up the van on the driveway for more than a few days - then all batteries are always kept at 100% .... you will notice if you have stop-go/recuperation with a smart alternator that after driving, the solar delivers more ... this is because the smart alternator and recuperation strategy tries to keep the batteries around 90% .. the solar then tops them up to 100% when you park up.

Some pics of the install ....

View attachment 101308View attachment 101309
View attachment 101311
View attachment 101310
Is this system available in the uk do you know
Any idea if cost please, thanks
 
Hi Andy,
Thanks a lot, the guy has done a real neat job and I think I will follow most of his approach. Really useful to me.

I did also mention fitting an extra changeover switch to top the starter battery up but I have decided to ditch that idea when I think back over my 6 years of ownership without any starter battery problems.
However I did discover under the passenger seat a direct line to the starter battery on the split relay if anyone else was thinking to trickle the starter battery.

Once again Andy, thanks for taking the time to post. It is helpful to me and others I think.

Cheers
Shadrack.
If your split relay isn't already dual bias, simply change it. They work both ways i.e. if either battery gets above a certain level e.g. 13.7v the relay closes and also charges the other battery. So when parked up with solar once the leisure batteries get above the voltage specified on the, relay it closes and also chargers your starter battery. They obviously work the other traditional way too, they also still open when the volts are getting too low to protect draining both sets of batteries.
 
If your split relay isn't already dual bias, simply change it. They work both ways i.e. if either battery gets above a certain level e.g. 13.7v the relay closes and also charges the other battery. So when parked up with solar once the leisure batteries get above the voltage specified on the, relay it closes and also chargers your starter battery. They obviously work the other traditional way too, they also still open when the volts are getting too low to protect draining both sets of batteries.
Thank you Kenny,

I think I am going to stick with getting the solar up and running to the leisure Batts just now as I my engine battery does seem to look after itself. Over the winter months i do tend to use hookup to keep all batteries healthy. When out and about in the warmer months it’s my leisure batts that gets the stick with the fridge, lights etc. Hopefully with a couple of hundred watts of solar I can be more or less free (weather dependent)from using hookups.

thanks again for your suggestion.
 
Is this system available in the uk do you know
Any idea if cost please, thanks
I built it myself from component parts ... here is the list of the major components in the diagram above, you need to add crimp terminals, heatshrink, cable, screws, sikaflex adhesive and other sundry items - and obviously build it and fit it yourself. I think the total cost was somewhere around €1700 for everything including sundries - but some prices have changed since then.

Hess 320W panel holder - Silver: https://shop.automobile-hess.ch/pro...ranlage-beim-vw-t5-t6-california-320-w-anlage

Phaesun Mare Flex 155W Solar Panels x 2: https://www.esomatic.de/solarmodule/semi-flexible-solarmodule/310423.html?number=310424

Scanstrut DS-H10 grey: https://lepper-marine.de/Scanstrut-Kabeldurchfuehrung-horizontal-DS-H10-grau/1053-00164

63A 2 Pole Circuit Breaker for Panels + housing: https://www.amazon.de/gp/product/B07D28J4K3/
https://www.amazon.de/gp/product/B08VMR2DWW/

Victron Smartsolar MPPT Laderegler 100/30: https://autobatterie-markt.de/a/victron-mppt-100-30-smartsolar-laderegler12-24v-30a/9883922/

Victron 100A Argofet Battery Isolator: https://www.amazon.de/gp/product/B00O8SQP0O/

Fuses: https://www.amazon.de/gp/product/B07JM9X78S/

Starter Battery Solar Switch: https://www.amazon.de/gp/product/B07XY3SKPN/

Victron MPPT Control: https://www.amazon.de/gp/product/B017T2XOE0/

Victron Smart Battery Sense: https://www.amazon.de/dp/B07RTYGMBD/
 
I built it myself from component parts ... here is the list of the major components in the diagram above, you need to add crimp terminals, heatshrink, cable, screws, sikaflex adhesive and other sundry items - and obviously build it and fit it yourself. I think the total cost was somewhere around €1700 for everything including sundries - but some prices have changed since then.

Hess 320W panel holder - Silver: https://shop.automobile-hess.ch/pro...ranlage-beim-vw-t5-t6-california-320-w-anlage

Phaesun Mare Flex 155W Solar Panels x 2: https://www.esomatic.de/solarmodule/semi-flexible-solarmodule/310423.html?number=310424

Scanstrut DS-H10 grey: https://lepper-marine.de/Scanstrut-Kabeldurchfuehrung-horizontal-DS-H10-grau/1053-00164

63A 2 Pole Circuit Breaker for Panels + housing: https://www.amazon.de/gp/product/B07D28J4K3/
https://www.amazon.de/gp/product/B08VMR2DWW/

Victron Smartsolar MPPT Laderegler 100/30: https://autobatterie-markt.de/a/victron-mppt-100-30-smartsolar-laderegler12-24v-30a/9883922/

Victron 100A Argofet Battery Isolator: https://www.amazon.de/gp/product/B00O8SQP0O/

Fuses: https://www.amazon.de/gp/product/B07JM9X78S/

Starter Battery Solar Switch: https://www.amazon.de/gp/product/B07XY3SKPN/

Victron MPPT Control: https://www.amazon.de/gp/product/B017T2XOE0/

Victron Smart Battery Sense: https://www.amazon.de/dp/B07RTYGMBD/
Thanks
 
Hi interested in the panels above / pics shown, where do i find these pls ?
 
Hi to all,
I have finally finished my solar winter project. I would like to thank everyone for their help and valuable input.
I was using a 120w folding suitcase panel prior but after seeing some of the great ideas and installations on the forum I decided to have a go myself.
I purchased an 8x4 sheet of 3mm aluminium, borrowed a friends workshop for his folder and guillotine, did a bit of bending etc. Paint and glued a couple of 100w flexible on each. as there were holes in panels I bolted them as well.
I did mount a changeover switch next to controller with Centre Off position. This was just to have the facility to top up the engine battery via solar if ever needed.
I have not really had the opportunity to give it a good testing just yet but all seems to be ok.
Once again big thanks to everyone.

D6BDCCDF-E794-4D75-849F-8EC27400FC35.jpeg

B31BC87F-67AE-4DAF-ABA9-FA264BC3DF51.jpeg

29732865-C3FD-4045-8146-EE01C12818A0.jpeg
 
Hi to all,
I have finally finished my solar winter project. I would like to thank everyone for their help and valuable input.
I was using a 120w folding suitcase panel prior but after seeing some of the great ideas and installations on the forum I decided to have a go myself.
I purchased an 8x4 sheet of 3mm aluminium, borrowed a friends workshop for his folder and guillotine, did a bit of bending etc. Paint and glued a couple of 100w flexible on each. as there were holes in panels I bolted them as well.
I did mount a changeover switch next to controller with Centre Off position. This was just to have the facility to top up the engine battery via solar if ever needed.
I have not really had the opportunity to give it a good testing just yet but all seems to be ok.
Once again big thanks to everyone.

View attachment 105141

View attachment 105142

View attachment 105143
Very nice! If you don't mind I have some questions that would help me with my project.
1. Do you have the drawings of the aluminium plate to share?
2. What is the curly cable exactly? (I tried to find such without success)
3. How did you connect it to the battery? Directly to the battery or to the hess wiring diagram as above? Do you have any photos?

Thanks in advance!
 
Hi, Leopold,
sorry for later reply, I am touring in the Netherlands at the moment and Wi-Fi has not been the strongest in some parts.

1, I am sorry I don’t have drawings, I just made them of the cuff so to speak. My friend who does small fabrications allowed me to use his folder and guillotine.
He ordered for me a 1200x2400x3mm Aluminium sheet (8x4) For me. I rocked up with my camper, cut the rough sizes then folded an end, when happy with that end did the other. What I did find that the shape or angles at the end had to be pretty accurate as when bolting to the rails if not true the shape would be effected.
The holes for the rear panel are forward a 50mm or so just to keep the panels nearer to the rear.
The curly pops over the ridge as the roof lifts nicely, I hear a couple of ‘clunks’ as it does so. I have attached some 3m helicopter tape under the curly to protect roof paint.

2, The Curley cable is something I discovered from our good Chinese friends from the east.
I wanted 2core with decent wires. I think it was 10 gauge I settled for with, very fine multistranded that would look after the physical aspect as well as very little voltage drop.
if you do a search on Alibaba’s site you will discover.

3, I connected directly to the positive of the rear leisure battery via an inline 20amp fuse.
the negative I connected to the ground at the point where this battery is clamped and secured to the chassis.

up to know they have behaved very well, my batteries are into their 7th year now and are doing very well. When parked up away from home front and rear dash cams are always recording. Fridge is on quite a bit for when I do my weekly shop.

All the information I gleaned and was helped by so many on this forum, I can’t thank enough. If you spend the time Leopold, some many good ideas, tips and tricks can be found here, just take the bits you think you need.
I will help further as I’m sure others will if it’s needed.
it’s a very worthwhile and rewarding project in many ways. My system came in well under £500 total cost

Good luck
 
Hi, Leopold,
sorry for later reply, I am touring in the Netherlands at the moment and Wi-Fi has not been the strongest in some parts.

1, I am sorry I don’t have drawings, I just made them of the cuff so to speak. My friend who does small fabrications allowed me to use his folder and guillotine.
He ordered for me a 1200x2400x3mm Aluminium sheet (8x4) For me. I rocked up with my camper, cut the rough sizes then folded an end, when happy with that end did the other. What I did find that the shape or angles at the end had to be pretty accurate as when bolting to the rails if not true the shape would be effected.
The holes for the rear panel are forward a 50mm or so just to keep the panels nearer to the rear.
The curly pops over the ridge as the roof lifts nicely, I hear a couple of ‘clunks’ as it does so. I have attached some 3m helicopter tape under the curly to protect roof paint.

2, The Curley cable is something I discovered from our good Chinese friends from the east.
I wanted 2core with decent wires. I think it was 10 gauge I settled for with, very fine multistranded that would look after the physical aspect as well as very little voltage drop.
if you do a search on Alibaba’s site you will discover.

3, I connected directly to the positive of the rear leisure battery via an inline 20amp fuse.
the negative I connected to the ground at the point where this battery is clamped and secured to the chassis.

up to know they have behaved very well, my batteries are into their 7th year now and are doing very well. When parked up away from home front and rear dash cams are always recording. Fridge is on quite a bit for when I do my weekly shop.

All the information I gleaned and was helped by so many on this forum, I can’t thank enough. If you spend the time Leopold, some many good ideas, tips and tricks can be found here, just take the bits you think you need.
I will help further as I’m sure others will if it’s needed.
it’s a very worthwhile and rewarding project in many ways. My system came in well under £500 total cost

Good luck
Many thanks Shadrack for your wide response! In this forum there's huge amount of knowledge indeed! Sometimes even to much ;)
 
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