310W permanent solar on a 22MY T6.1 Ocean

[Oceanis]

Wiring Diagram of my 310W solar install on a VW California Ocean. Anything marked VW is VW OEM equipment, the rest is available on t'internet.



I am in the process of building and fitting. (Fusing is not yet finally decided as it depends on component locations, wire lengths etc.)

Notes:

Due to the panel size and my preference for Victron kit, I chose a SmartSolar MPPT 100/30. The Victron website suggested a 100/20 but it would throttle the charge current to 20A with a 310W solar setup which is wasting energy.

I have tested series/parallel on my sailing boat (also a 300W system) and over two 7 day periods in the Adriatic it made no discernable difference to the daily yield - the mast, boom, and sails regularly shade the panels. I therefore settled on series as it pulls the voltage well above the startup voltage of the MPPT and generates less current, therefore less loss in the solar panel wiring for a given wire size. As my panels came with 2.5 mm2 wiring, they will be wired in series.

The SmartSolar MPPT 100/30 only has one output so charging both the starter and leisure batteries from it was going to be a challenge.

VW has an Isolation Relay controlled by the VW Special Vehicle Control Unit and the VW Battery Charger ... it sits between the Starter Battery and the Leisure Batteries. This means I either bridge the relay (not good on modern cars because of recuperation and stop/start) or I have to find a way to charge both battery banks independently with no current transfer between the two charging circuits (unless the VW components decide it is safe to close the relay - which is OK.)

To do this I am fitting a 2 output 100 Amp Victron Argofet. One output goes to the leisure batteries, the other to the starter battery and they will be isolated from each other. The fly in the ointment is that the Victron MPPT will also be isolated and therefore will not power up - fortunately, this can be solved by applying 12v to the "Energize" input to the Argofet. When this input is switched live, it will provide 12V to the Victron MPPT - the function was designed for use with the exciter coils on an alternator but will work fine (hopefully) with the MPPT too.

... any comments or observations welcome.

 

[Dilbert]

To do this I am fitting a 2 output 100 Amp Victron Argofet. One output goes to the leisure batteries, the other to the starter battery and they will be isolated from each other.

Are the starter battery and leisure batteries identical capacities and chemistries? I guess not so I do not think the charger(s) will be able to manage the charging profiles and charging stages correctly for the 2 battery types\functions.

 

[Oceanis]

Are the starter battery and leisure batteries identical capacities and chemistries? I guess not so I do not think the charger(s) will be able to manage the charging profiles and charging stages correctly for the 2 batteries.

They are currently all charged from the one output of the VW charger, which closes the isolation relay when on a hook-up - it seems to do this immediately. The "Max Charge" function seems to do the same with the alternator as the charge source.

I've measured the charge voltages on the battery poles with a multimeter when on hook-up - 14.6/14.7 V absorption then dropping to around 13.5V float.

All batteries are 75Ah AGMs and with the isolation relay closed they are all in parallel - I assume (perhaps incorrectly) that VW did their homework and the voltage supplied at each battery is the same.

I am worried that the starter battery may get held too long in absorption by run-down leisure batteries, but everything is a compromise and a new 75Ah AGM every once in a while isn't too expensive.

 

[Dilbert]

I should add there is plenty of information on here regarding the virtues (or lack of) of the VW California charging system. There is also lots of information on solutions to maintain the charge on the starter battery from the leisure battery.

 

[Oceanis]

I should add there is plenty of information on here regarding the virtues (or lack of) of the VW California charging system. There is also lots of information on solutions to maintain the charge on the starter battery from the leisure battery.

I'm reading through a few of them at the moment.

My experience on my boat was that the MPPT provided power as and when needed ... there were a lot of permanent electric loads parallel to charging the batteries and the MPPT powered everything on the boat when at anchor (including charging the batteries). The batteries were full by mid-day and drained to about 85% between sunset and sunrise - I also charged the house and starter battery with the one MPPT output through a combiner. Didn't have any battery problems.

Will see how this goes, if necessary I'll fit a trickle charger between the leisure and starter batteries.

Boat system looked like this ...

 

[Oceanis]

Got a bit further after having a think and working through the wiring diagrams for my 22MY T6.1 Ocean .... and it's got more complicated.

I plugged my van into a CEE hook up for 3 days to get the batteries all charged (as much as the VW system will do anyway) and then put it on a meter and used it for 24hrs. Put fridge on 5, heating on 3, lived in the van, coming and going, locking/unlocking etc.

To my horror it used 1.1 kWh from my mains supply in 24 hrs. Some of this will be down to the losses associated with my power source and charging but it's a bigger number than I expected. Just manageable with 310W of solar in southern europe, but a challenge.

Anyway, what was really concerning me was the smart alternator, regen start/stop stuff and although I wanted the Victron MPPT to charge all 3 vehicle batteries, I didn't want the system connected to the starter battery when the vehicle was being driven, or permanently bridging the isolation relay for the 2nd and 3rd batteries. I still want it to charge the 2nd / 3rd batteries when driving though - it will make the Max Charge function in the camper unit partially redundant - but I want solar always charging the 2nd/3rd battery regardless of vehicle state, and I want it all isolated from the starter battery when the vehicle is being driven.

All this has lead me to version 3 (or higher) of my plan ...



The solar bit up to the MPPT is pretty standard and nothing special.

The Victron Argofet 100-2 provides some interesting functionality ....

It was designed for use with old-school alternators, providing isolated charging from an alternator to 2 separate batteries. There is no charging intelligence in it (that comes from the Victron MPPT) but because it uses FETs instead of diodes it has a very low voltage drop and completely isolates the batteries from each other - it will direct charge current to batteries 2/3 and the starter battery separately.

So far so good ...

The fly in the ointment is the MPPT which expects a battery on its charge terminals (permanent 12v) ... the Argofet blocks any current flow from the batteries but it has another function designed for old-school alternators which can be used to power the MPPT.

It has an "energize" input - this was originally used to supply a current to the exciter coils of an alternator which was needed for older alternators which weren't self-exciting. When 12V is applied to the energize input, the Argofet will provide 12V to the connected MPPT. I have added a switch on this line so I can completely isolate all the solar components if necessary.

The next problem was, even though the leisure and starter batteries are isolated from each other, the starter battery would be getting a charge voltage from the MPPT - even with the engine running. To solve this I used a changeover relay ... this will disconnect the starter battery from the Argofet when the ignition is switched on. Then the starter battery side of the system will be completely disconnected from my solar install, leaving the smart alternator to do its thing with regen, start-stop etc.

I suspect the VW Max Charge function in the Camper Unit closes the VW isolation relay and turns off not just start/stop but pulls enough from the alternator to charge all batteries. (This is allowed by the emissions regulations as long as on the next life-cycle it reverts to start/stop, regen etc.) ... this will not be upset by a parallel solar charger.

... next problem ... and I'm already trawling old threads and scouring the wiring diagrams for an answer .... where to get an "ignition on" (KL15) signal from for my starter battery isolation relay?

Any constructive criticism gratefully received.

 

[Oceanis]

Thread looking for feedback on a solar install I am doing on my California Ocean with the goal of being energy independent.

 

[Dellmassive]

have a quick look over here. . .

you might see something useful . . .

Dellmassive’s "How I Done It" blogs.

-- Dellmassive`s -- "How I Done It" -- thread -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

www.t6forum.com

.

 

[t0mb0]

Got a bit further after having a think and working through the wiring diagrams for my 22MY T6.1 Ocean .... and it's got more complicated.

I plugged my van into a CEE hook up for 3 days to get the batteries all charged (as much as the VW system will do anyway) and then put it on a meter and used it for 24hrs. Put fridge on 5, heating on 3, lived in the van, coming and going, locking/unlocking etc.

To my horror it used 1.1 kWh from my mains supply in 24 hrs. Some of this will be down to the losses associated with my power source and charging but it's a bigger number than I expected. Just manageable with 310W of solar in southern europe, but a challenge.

Anyway, what was really concerning me was the smart alternator, regen start/stop stuff and although I wanted the Victron MPPT to charge all 3 vehicle batteries, I didn't want the system connected to the starter battery when the vehicle was being driven, or permanently bridging the isolation relay for the 2nd and 3rd batteries. I still want it to charge the 2nd / 3rd batteries when driving though - it will make the Max Charge function in the camper unit partially redundant - but I want solar always charging the 2nd/3rd battery regardless of vehicle state, and I want it all isolated from the starter battery when the vehicle is being driven.

All this has lead me to version 3 (or higher) of my plan ...

View attachment 154040

The solar bit up to the MPPT is pretty standard and nothing special.

The Victron Argofet 100-2 provides some interesting functionality ....

It was designed for use with old-school alternators, providing isolated charging from an alternator to 2 separate batteries. There is no charging intelligence in it (that comes from the Victron MPPT) but because it uses FETs instead of diodes it has a very low voltage drop and completely isolates the batteries from each other - it will direct charge current to batteries 2/3 and the starter battery separately.

So far so good ...

The fly in the ointment is the MPPT which expects a battery on its charge terminals (permanent 12v) ... the Argofet blocks any current flow from the batteries but it has another function designed for old-school alternators which can be used to power the MPPT.

It has an "energize" input - this was originally used to supply a current to the exciter coils of an alternator which was needed for older alternators which weren't self-exciting. When 12V is applied to the energize input, the Argofet will provide 12V to the connected MPPT. I have added a switch on this line so I can completely isolate all the solar components if necessary.

The next problem was, even though the leisure and starter batteries are isolated from each other, the starter battery would be getting a charge voltage from the MPPT - even with the engine running. To solve this I used a changeover relay ... this will disconnect the starter battery from the Argofet when the ignition is switched on. Then the starter battery side of the system will be completely disconnected from my solar install, leaving the smart alternator to do its thing with regen, start-stop etc.

I suspect the VW Max Charge function in the Camper Unit closes the VW isolation relay and turns off not just start/stop but pulls enough from the alternator to charge all batteries. (This is allowed by the emissions regulations as long as on the next life-cycle it reverts to start/stop, regen etc.) ... this will not be upset by a parallel solar charger.

... next problem ... and I'm already trawling old threads and scouring the wiring diagrams for an answer .... where to get an "ignition on" (KL15) signal from for my starter battery isolation relay?

Any constructive criticism gratefully received.

Using 1.1kWh over 24hr does seem extremely high without obvious high drains like electric hobs/kettles/etc, it’s almost equivalent to a constant 4A. What kind of fridge/heater have you got?

 

[Oceanis]

Using 1.1kWh over 24hr does seem extremely high without obvious high drains like electric hobs/kettles/etc, it’s almost equivalent to a constant 4A. What kind of fridge/heater have you got?

Standard VW fridge (42L compressor fridge - Secop 101N0650 coupled to a BD35F) and standard VW diesel air heater fitted to a California Ocean.

 

[AussieMick]

My general observation after using solar to recharge my leisure battery off the grid on extended travel.
Many people are surprised how quickly their leisure battery runs out of usable power when parked for a few days.

It was no good having large amounts of panel/s without a decent storage battery.
An agm battery can only be discharged to 50percent of capacity regularly or you shorten the battery life.

You get days of cloudy weather with little or no sunshine and this puts nothing back into the battery so without adequate battery storage you run out of usable power even though you have a large solar panel.

I found the only answer for me was a 150ah lithium lifepo4 battery as it will give me about 4 days power without sunshine to recharge leisure battery with the loads I draw. Lithium recharges much faster than agm which I found took all day in some conditions to only part charge my battery.
I run a fridge, diesel heater, led lighting and usb charging.
If moving around this would help put charge back in the battery but parked for several days without sun will soon deplete your usable power in a system that has big panels but small battery storage.
As I said this is only my observation as your circumstances may be different how you use your van as you are hoping to be energy independent I believe.

 

[Oceanis]

My general observation after using solar to recharge my leisure battery off the grid on extended travel.
Many people are surprised how quickly their leisure battery runs out of usable power when parked for a few days.

It was no good having large amounts of panel/s without a decent storage battery.
An agm battery can only be discharged to 50percent of capacity regularly or you shorten the battery life.

You get days of cloudy weather with little or no sunshine and this puts nothing back into the battery so without adequate battery storage you run out of usable power even though you have a large solar panel.

I found the only answer for me was a 150ah lithium lifepo4 battery as it will give me about 4 days power without sunshine to recharge leisure battery with the loads I draw. Lithium recharges much faster than agm which I found took all day in some conditions to only part charge my battery.
I run a fridge, diesel heater, led lighting and usb charging.
If moving around this would help put charge back in the battery but parked for several days without sun will soon deplete your usable power in a system that has big panels but small battery storage.
As I said this is only my observation as your circumstances may be different how you use your van as you are hoping to be energy independent I believe.

Yep, that fits with my calculations too, energy independence is the goal and I will be using about 750 Wh a day - which with only 150 Ah (2 x 75Ah) AGM batteries (1800 Wh) will take me to 50% in 29 hours - not good enough.

Phase 2 of my project is to add capacity ... my goal for the boat was 3 days in total darkness - which never actually happens, but worked out as a good rule of thumb as we never dropped below 85% charge with the system shown in the post above (300W solar and 370Ah of SLA batteries in the Adriatic).

I need approx 2250 Wh of useable battery capacity .... so taking that as 80% of a Lithium battery I need around 230Ah of Lithium to survive my 3 days of darkness ... depending on the space freed up by the 2 leisure batteries I may end up with around 200Ah we will see - 200Ah would probably be OK.

It was important for me to first fit a solar array capable of 750Wh a day in normal conditions ... and 310W will do this where I use the van.

Although I won't see a yield like in this graph in real conditions, there is enough headroom to assume 750Wh a day during summer.



In the Adriatic it looks like this and 300W solar was regularly pumping out 0,9 kWh a day in summer ...



PS: I'm a fair weather camper and after 1-2 overcast, rainy days, I'd probably head to civilisation and plug in.

 

[AussieMick]

Ok, sounds like you have done your sums and have it covered.
A 200ah lithium will give you the headroom you are after but it will be pricey and maybe too large to fit where you want to put it but will weigh much less than 2 agm batteries.
I use about 40ah a day on a typical day with my loads and 150ah lifepo4 battery with 280w of solar panels is enough to keep me going indefinitely providing it's not overcast for over 3 /4 days in a row and I am parked.
I guess if this happens we have the option of moving on which will help put charge back via the alternator.
I have a victron bmv712 battery monitor so its easy to keep track of how much charge accurately is left in your battery in real time for the load you are drawing. Its good for monitoring the solar input as well so a handy piece of equipment to fit.
I have been out on a trip for a few months with my setup and had no power issues and the solar panels charged my battery back to 100 % each day but when I had a 120ah agm battery it was a juggling act trying to not go below 50% of battery capacity some days especially in hot weather as my fridge ran nonstop using a lot of power .

 

[Salty Spuds]

I must be missing something. We live in the frozen north, we have a 180w solar panel, 100Ah lithium battery, ablemail amt12. We can quite happily survive off grid in a north of England summer and in an alpine winter. In the Alps, we use the Webasto to heat the van & the fridge is doing minimal work. In summer, we spend a couple of months in Portugal where we run 2 fridges & no heater.
When at home, it’s a mix of fridge & heater with middling sun. We’ve never run the battery past 20%. I can’t help but wonder if the OP is overthinking his “problem”

 

[Dellmassive]

I think I would just swap out those two AGMs for two lithium 100ah....

Or just fit a 230ah seat base battery.

That will give you 2400wh plus.....

If you needed more capacity..... Just drop in another lithium.

I've seen a recent build that used 4x renogy 100 ah batts in the back locker.

 

[Oceanis]

I must be missing something. We live in the frozen north, we have a 180w solar panel, 100Ah lithium battery, ablemail amt12. We can quite happily survive off grid in a north of England summer and in an alpine winter. In the Alps, we use the Webasto to heat the van & the fridge is doing minimal work. In summer, we spend a couple of months in Portugal where we run 2 fridges & no heater.
When at home, it’s a mix of fridge & heater with middling sun. We’ve never run the battery past 20%. I can’t help but wonder if the OP is overthinking his “problem”

I'm glad it works for you but I have no idea how you use your van so I can't really make any comparisons. I do know how I use my van and what electrical consumers I have (now and planned) and how much energy they use daily. The van will also be used as a home office all year round as well as for good weather holidays ... maybe that is different to you?

 

[Dellmassive]

@Oceanis

have you seen the 230ah seat base lifepo4 batterys from @RoamerBatteries

Roamer LiFePO4 Gen2 230Ah Seatbase battery -- "How I Done It" --

Roamer LiFePO4 Gen2 230Ah Seatbase battery -- "How I Done It" -- Its a Lithium LifePo4, its got massive capacity @ 230Ah, its got massive discharge performance 250A/500A, its Bluetooth, its a Roamer !!, its exciting . . . . . its coming soon - the full test . . . . ...

www.t6forum.com

.



....



or the other lithium threads?



LIFPEO4:

• Lithium Lifepo4 12v Batteries -- Time For An Upgrade ? --
• Valence U27-12XP Lifepo4 Lithium Battery -- How We Done It --
• SUBZERO - low temperature lithium battery -- How We Done It --
• Roamer LiFePO4 Gen2 230Ah Seatbase battery -- How I Done It --
• 12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It --
• Awesome-3-in-1-battery-bank -how-i-done-it.
• Solar-Generators - How i Done it -
• 200Ah, 2000W, LifePo4 Leisure Battery Box -- How I Done It --
• Renogy - 12V 100AH Lifepo4 BATTERY W/ BLUETOOTH RBT100LFP12-BT-UK
• Renogy 12V 100Ah SMART LiFePO4 Battery RBT100LFP12S
• RENOGY 12V 100AH SMART Lifepo4 BATTERY W/ SELF-HEATING FUNCTION
• Poweroad 100Ah Lifepo4 LowTemp Battery

 

[Salty Spuds]

I'm glad it works for you but I have no idea how you use your van so I can't really make any comparisons. I do know how I use my van and what electrical consumers I have (now and planned) and how much energy they use daily. The van will also be used as a home office all year round as well as for good weather holidays ... maybe that is different to you?

Very valid points. We use our van for extended skiing trips to the Alps in winter & a couple of months touring Europe in early summer, then September/ October touring the UK, so we spend a good 4-5 months a year in the van in very varied conditions. You obviously have differing needs & requirements to us, which is fair enough, but I can't help thinking that you are overcomplicating what should be a simple installation. Maybe it's because you are trying to utilise legacy equipment from the Ocean.
You asked for comments & observations, my main offering is keep it simple. Trying to fault find electrical issues in the tiny confines of a packed campervan isn't fun. Forget the isolation relays/argofets etc. Stick a couple of good quality panels on the roof, a suitable Victron MPPT, however much Lithium capacity you think you need, and a maintainer for the starter. Job done.
That's just my opinion for what it's worth.

 

[Dellmassive]

Very valid points. We use our van for extended skiing trips to the Alps in winter & a couple of months touring Europe in early summer, then September/ October touring the UK, so we spend a good 4-5 months a year in the van in very varied conditions. You obviously have differing needs & requirements to us, which is fair enough, but I can't help thinking that you are overcomplicating what should be a simple installation. Maybe it's because you are trying to utilise legacy equipment from the Ocean.
You asked for comments & observations, my main offering is keep it simple. Trying to fault find electrical issues in the tiny confines of a packed campervan isn't fun. Forget the isolation relays/argofets etc. Stick a couple of good quality panels on the roof, a suitable Victron MPPT, however much Lithium capacity you think you need, and a maintainer for the starter. Job done.
That's just my opinion for what it's worth.

Some good advice that . . . id add that a good quality DC-DC charger is as important too.

if running lithium they will pull full current from any charger. . . . so if you look at say the Renogy offering you can set the current limiter via the APP. . . eg 30A on the 50A unit.

that will keep the unit nice and cool . . .and its finless. . . . . plus it will be reliable as you only running at 60% capacity.

 

[Dellmassive]

@Oceanis

have a look at some of the setups . . .

Diagrams, Schematics & Wires -- How I Done It --

Diagrams, Schematics & Wires -- How I Done It -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

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