Solar install on a T6.1 California Ocean ...

[California_Ocean]

Anytime your spilt charge relay engages current will flow from the batteries at a higher state of charge to the lower state of charge.

The only way to achieve what you want is to isolate the two buses, either with a smps or diode or diode like device. The diode solution will need current limiting.

[Edit] Caveat: the alternator, if operating, may complicate things.

I think your simplest solution will be remove the relay and install a smps, a B2B in forum speak. You could leave your Argofet in place and things will probably work quite well.

Unfortunately the VW system controls the isolation relay between the starter and leisure banks and it is used as part of the charging strategy when on shore power. (as well as the start/stop, recuperation and Max Charge logic)

The VW charger is attached to the leisure bank and when shore-power is detected, the relay is closed to allow starter battery charging. Not sure what the logic is, both batteries simultaneously, leisure priority, or even stop charging the starter at 80%. I don't want to mess around with the original VW wiring for fear of screwing up whatever charging strategy they run - and killing the Max Charge feature. I also can't completely remove the isolation relay or I get fault codes generated.

The Argofet arrangement seems to work very well when the van is parked up and unused, and the solar works fantastically when only charging the leisure batteries.

A simple switch for both options may be the answer.

 

[yossarian]

The mppt has a load output function which could be used to drive a relay when the leisure batteries are at float.

User defined algorithm no 1 is probably what you're after.

You will want to current limit the path in case an engine start occurs. But if the path is mppt - argofet - relay - starter battery no current limit necessary.

Closing the relay might lower the voltage sensed by the mppt. There is some debouncing built in but you might need to consider this . The algorithm has some hysteresis setting you can do.

 

[yossarian]

The load output settings be used to drive the TX pin in the VE.Direct port, which can then be used to drive a BatteryProtect, a relay or an other load-shedding device. For more information see chapter TX

 

[California_Ocean]

The mppt has a load output function which could be used to drive a relay when the leisure batteries are at float.

User defined algorithm no 1 is probably what you're after.

You will want to current limit the path in case an engine start occurs. But if the path is mppt - argofet - relay - starter battery no current limit necessary.

Closing the relay might lower the voltage sensed by the mppt. There is some debouncing built in but you might need to consider this . The algorithm has some hysteresis setting you can do.

I've snookered myself by using the VE.Direct port to run a Victron MPPT Display.
I think the solution is to use a MPPT with a load output and hang a trickle charger to the starter battery on it.

 

[California_Ocean]

Final Solution, in the end I ended up with this ...


Put a switch into the feed to the starter battery and will switch it on if the van is parked up for more than a few days. The solar will then charge everything while the engine isn't running.

I also put a Vicron Smart Sense on the first leisure battery so it transmits battery temperature and voltage to the MPPT.

All seems to be working really well.

If doing it again I would use a MPPT with a proper load output and connect a good trickle charger for the starter to the MPPT load output instead of using the Argofet.

I thought making the full MPPT current available to the starter battery would be a good idea, I didn't realise it would cause the smart alternator to cut it's output.

 

[California_Ocean]

Found these ...

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Basically drop in batteries that fit the same space as the AGMs currently in my T6.1, with the same terminals.

So ... been toying with fitting LiFePO4 batteries for a while, but obviously from the factory it is set up with 2 x 75Ah AGM leisure batteries and a VW charger and smart alternator, also set up for AGM batteries. There are shunts on all the batteries and the camper unit monitors how full they are (obviously knowing they are 75Ah AGM batteries) ... so bit of a headache to integrate into the VW system and replace the AGMs with Lithiums .... but I think I have a solution and would be grateful for any observations or mistakes in the following diagram. Everything to the left of the blue dotted line is VW original and the right are my additions.



When parked, the solar will charge both the Lithiums and the AGM starter. (Starter Trickle Switch set to "On")
When on Shore Power, the VW charger will charge the AGM starter because when the charger runs, it closes the isolation relay. The VW charger will also charge the Lithiums via the DC-DC (Starter Trickle Switch can be "Off or "On" but will have no effect)
When engine is running, the DC-DC and the MPPT will charge the Lithium batteries. (Starter Trickle Switch best set to "Off", On will fight the smart alternator, but I have this at the moment and it has no discernable effect other than producing a much bigger solar yield.)

The position of the switch isn't critical and the battery protect will protect the lithium batteries from discharging when there is not a charging source present.

That is my thinking ... anyone notice any glaring errors?

Will take the plunge this summer and see how the Camper Unit copes with this setup and how it reports the battery status. If it is too confused then I will put in Victron shunts and monitor the leisure batteries with a battery monitor.

Future projects are a CerboGX OS running on a Raspberry Pi, and an Inverter upgrade.

 

[Kayleigh]

If you have two 75Ah AGM leisure batteries and two 100W solar panels, do you really need lithium batteries?

To me, it is all about right-sizing the system. If your leisure batteries are drained before solar can start again in the morning, then maybe there is a case. However, there is a simpler alternative and that is to add a small power station from the likes of Anker, Ecoflow etc for items that are non-essential to the operation of the California.

 

[California_Ocean]

If you have two 75Ah AGM leisure batteries and two 100W solar panels, do you really need lithium batteries?

To me, it is all about right-sizing the system. If your leisure batteries are drained before solar can start again in the morning, then maybe there is a case. However, there is a simpler alternative and that is to add a small power station from the likes of Anker, Ecoflow etc for items that are non-essential to the operation of the California.

This is phase two of an ongoing project ... I also want to fit a bigger inverter to run a toaster, a hairdryer and maybe a Thermomix. (Not currently calculated in my energy budget). My daily usage is currently around 0,79kWh (65Ah - which is almost my total capacity as I don't want to discharge the AGMs to less than 50%). In winter the solar struggles to replace this and I want at least to survive a long weekend stationary with no electrical hook-up.

I'm not really a fan of Anker etc. ... the two drop-in 100Ah Lithiums will get me 2560 Wh without taking any more space and will weigh 18kg less than my AGMs .... I will still need the inverter but as a comparison an Anker PowerHouse 767 with 2048 Wh will add 30 kg. I need to find space in the boot for it - and to use it in the van I need access to it ... all the advertising shows shiny happy families sitting outside, but space to use one in the van is very limited without burying it in the boot with 230v extension cables into the living area, or running a cable outside to the shore-power inlet - but then you can't access the controls or connections. It would be awesome for a tent though.

I basically want the functionality of a power station, integrated, without the 30kg brick in the boot.

The Ocean is also a test-bed for my boat, I'm planning a lithium system that currently looks like this ...

... so the van is a bit of a dry run to see how Lithium and Solar interact, and what I can do with a 2000W inverter .... what I have heard from other boat owners is that Lithium batteries due to their ability to accept large charging currents for longer than lead-acid, results in the solar panels producing a much larger yield, and I want to see how much I get out of my 310W array.

 

[RichardW123456]

No problem with Roger's setup (we purchased one panel only and seem to be fine but not using in the winter) but with one small difference in that I asked for a long lead directly wired into the van rather than an external connector - makes removing or repositioning the panels a simple task if you need to carry something else on the roof.
A question I do have is that does anyone know if there is an issue charging the batteries to ~100% level via the panel in terms of long term battery health? I was a bit concerned as the Cali' system will disconnect the alternator etc when driving until back down to 80%? I get a better economy on the commute by 5-10% but was worried this sunny weather continual extra charge/discharge was an issue? The option is to drop the solar charge level down to ~the same as the VW charge 80% level which may take some digging on...

 

[Californication69]

No problem with Roger's setup (we purchased one panel only and seem to be fine but not using in the winter) but with one small difference in that I asked for a long lead directly wired into the van rather than an external connector - makes removing or repositioning the panels a simple task if you need to carry something else on the roof.
A question I do have is that does anyone know if there is an issue charging the batteries to ~100% level via the panel in terms of long term battery health? I was a bit concerned as the Cali' system will disconnect the alternator etc when driving until back down to 80%? I get a better economy on the commute by 5-10% but was worried this sunny weather continual extra charge/discharge was an issue? The option is to drop the solar charge level down to ~the same as the VW charge 80% level which may take some digging on...

Interesting you say this.
I guess a solution would be to have 3 panels on the roof, so hopefully charge to 100%
Then take the better economy, whilst commuting.
So a win win situation.
Just when driving to a campsite, hit the Max Charge button and Lesuire will stay at 100%

 

[yossarian]

No problem with Roger's setup (we purchased one panel only and seem to be fine but not using in the winter) but with one small difference in that I asked for a long lead directly wired into the van rather than an external connector - makes removing or repositioning the panels a simple task if you need to carry something else on the roof.
A question I do have is that does anyone know if there is an issue charging the batteries to ~100% level via the panel in terms of long term battery health? I was a bit concerned as the Cali' system will disconnect the alternator etc when driving until back down to 80%? I get a better economy on the commute by 5-10% but was worried this sunny weather continual extra charge/discharge was an issue? The option is to drop the solar charge level down to ~the same as the VW charge 80% level which may take some digging on...

Battery health improves the closer you keep them to 100% (or very slightly below.)

Fuel economy improves the more solar power you harvest.

 

[couplands]

Battery health improves the closer you keep them to 100% (or very slightly below.)

Fuel economy improves the more solar power you harvest.

A lot of battery chemistry states that max battery health is when the battery is at approx 85%. Not sure if this is still the case for AGM batteries..?

The Cali itself generally charges the leisure battery to 85% for most of the time and only to 100% if you absolutely need it.

 

[Californication69]

If you have two 75Ah AGM leisure batteries and two 100W solar panels, do you really need lithium batteries?

To me, it is all about right-sizing the system. If your leisure batteries are drained before solar can start again in the morning, then maybe there is a case. However, there is a simpler alternative and that is to add a small power station from the likes of Anker, Ecoflow etc for items that are non-essential to the operation of the California.

Just realised this is a very valid point.
If the two “onboard Lesuire” batteries will NOT hold enough amperage to run whatever you are using through the evening and night, then you need a “storage container” like you say @Kayleigh

My question for the group is what level should the starter battery be holding enough charge to start the vehicle.
So for eg: your parked up at the airport for two weeks. And everything is turned off.
The starter battery should be at, (if you used Max charge en route) 12.8v
Over two weeks you’d expect what, a .5v drop?
So as long as the starter Batt has 12.3v to crank a cold starter, then it’s all good.
At what point is the starter batt voltage too low to crank ? 12v 11.9v ?

 

[yossarian]

A lot of battery chemistry states that max battery health is when the battery is at approx 85%. Not sure if this is still the case for AGM batteries..?

What we call AGM is a variant of Lead chemistry batteries. Technically they are VRSLA with Absorbed glass mats. One can apparently purchase some other variants but the VRSLAs are what we're talking about. AGM is not a chemistry it is a construction technique.

 

[jonr71]

If you have two 75Ah AGM leisure batteries and two 100W solar panels, do you really need lithium batteries?

To me, it is all about right-sizing the system. If your leisure batteries are drained before solar can start again in the morning, then maybe there is a case. However, there is a simpler alternative and that is to add a small power station from the likes of Anker, Ecoflow etc for items that are non-essential to the operation of the California.

This is exactly my setup. I use a smallish ecoflow (576kwh) for items that I need to run off 240v. So I work from the van and need to power my laptop. I want to be able to recharge camera batteries and I want to be able to top up my ebike battery (700kwh) on some days among other things. Each of these either requires the inverter and drains my capacity to run the van or would require electrical hookup. It also serves as a useful reserve should my leisure batteries run low for some reason.

The battery is charged once my leisure batteries are full (need to consider whether 85% is a better level) from my 200w solar panels. It seems to cover all my needs so far - but I am not running things that have a huge wattage requirement that might mean I need high watts for an extended period.

 

[WelshGas]

Just realised this is a very valid point.
If the two “onboard Lesuire” batteries will NOT hold enough amperage to run whatever you are using through the evening and night, then you need a “storage container” like you say @Kayleigh

My question for the group is what level should the starter battery be holding enough charge to start the vehicle.
So for eg: your parked up at the airport for two weeks. And everything is turned off.
The starter battery should be at, (if you used Max charge en route) 12.8v
Over two weeks you’d expect what, a .5v drop?
So as long as the starter Batt has 12.3v to crank a cold starter, then it’s all good.
At what point is the starter batt voltage too low to crank ? 12v 11.9v ?

I’ve managed 5 weeks and 2 days parked at Heathrow T5 long stay during winter and it started 1st time and the ambient temperature was -4c.
Didn’t check the voltage.

 

[Californication69]

I’ve managed 5 weeks and 2 days parked at Heathrow T5 long stay during winter and it started 1st time and the ambient temperature was -4c.
Didn’t check the voltage.

Thanks WG, did you have Solar with DuoRacer trickle charging starter ?
my starter has lost 25% charge in 2 days and 13 hours.
20 hours on EHU and only got to 12.6v
It’s on 12.3v now.
I’ve removed Solar to test.

 

[WelshGas]

Thanks WG, did you have Solar with DuoRacer trickle charging starter ?
my starter has lost 25% charge in 2 days and 13 hours.
20 hours on EHU and only got to 12.6v
It’s on 12.3v now.
I’ve removed Solar to test.

No. Just 1 panel that charges leisure batteries. No connection to engine battery. So unless there is some unknown method of trickle charging engine battery when leisure batteries are full without a direct connection then this is just the engine battery on its own charged only by the alternator on the 180 mile trip from home to Heathrow.

 

[CaliforniaSeb]

Hi, Looking into getting John to fit his kit onto my camper . Has anyone who has fitted this kit had any water ingress in the tailgate? From what I can see on the pictures the cable is going in through the top tailgate gap where the rubber seals are.

 

[CaliforniaSeb]

Hi, Looking into getting John to fit his kit onto my camper . Has anyone who has fitted this kit had any water ingress in the tailgate? From what I can see on the pictures the cable is going in through the top tailgate gap where the rubber seals are.

Roger Donoghue. No idea why I typed "john" !

 

[Dell]

Hi, Looking into getting John to fit his kit onto my camper . Has anyone who has fitted this kit had any water ingress in the tailgate? From what I can see on the pictures the cable is going in through the top tailgate gap where the rubber seals are.

I have had mine on there now since September and have had plenty rain whilst driving and stopped and I have had no issues with water ingress. It is just a small split in the rubber that houses more cables. Basically the solar panel cables just push through sealing itself.

 

[Californication69]

Roger Donoghue. No idea why I typed "john" !

I have rogers curly cable and I slit the rear rubber.
No leaks.
This is my 2nd California and 2nd Solar from Roger.
No leaks

 

[Ch1pbutty]

Hi, Looking into getting John to fit his kit onto my camper . Has anyone who has fitted this kit had any water ingress in the tailgate? From what I can see on the pictures the cable is going in through the top tailgate gap where the rubber seals are.

We have the curly cable and have never had an issue with leaks.

 

[CaliforniaSeb]

We have the curly cable and have never had an issue with leaks.

Ok I'm in . Will book Roger to install some panels.