Warwick XL - Off-grid modifications

We have been away for a while but we would like to share the latest implementation in our mods and hear your opinion.

Like most van owners we are faced with the dilemma to keep the vehicle battery topped up when not driving for long periods.

As described earlier we had disconnected the original PX300 charger (incompatible with our 200Ah LiFeP04 battery) and the original black solar regulator (incompatible with our 200Ah LiFeP04 battery and solar panels)

So this means that we had no way to keep the vehicle battery charged besides driving (the EasyPlus aux output is not yet connected to the Vehicle battery).

I came up with this solution that seems working ok.

The Victron MPPT 75/15 solar controller has a "load output" terminal. I have wired this terminal to the input terminal of the original 10 amp solar regular.
The output of the original solar regulator is then wired back into the EC500 as it was originally.
Using the Victron App, I have configured the Load Output to "Battery Life" (it should protect the LiFeP04 to be discharged excessively )
Using the hidden menu in the E480 Control Panel, I have configured the EC500 Solar Charger, from Smart to Vehicle. This ensures that all power received from the old Solar Regulator is routed to the Vehicle.

The result is that the EC500 "believes" it's receiving solar power and charges the Vehicle battery (see pictures)
I am not sure if this is a good permanent solution (we do plan to install a "battery master") but it indeed saved us today.

Yesterday, by mistake we had switched battery selection on the EC480 to Vehicle (how can one disable this feature?) and without the sun it drained completely the battery.
The vehicle could not start.
Today, after fixing the problem, the sun was back and charged the vehicle battery back as it should.
Let me know what you think of this solution and if you believe we are doing something wrong
Thanks!

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Not sure if I'm misunderstanding what you have done, but if you are putting two solar chargers in series, I'm surprised that you are getting any solar charging at all! So I'm probably misunderstanding.

The reason is that most solar chargers are built with an assumption that the solar panel output will be in the range 19-26V (roughly). The output of a solar charger operating into a nominal 12V system should never exceed around 15V, so it would seem impossible for the output of one to reach the minimum operating threshold of the second! So I must be misunderstanding!

I should add that I have never tried it, so in real world conditions I don't know. I would expect to get a small amount of charge through, but I wouldn't expect it to be able to get anywhere near the panel's capacity.

gobsmacked
your wiring the white cable going in from the roof normally goes to a joint and into the lovely sargent wiring and down to the solar controller .this I always put a new complete wire from panel down to the solar controller so now has no joints that cant be seen and the correct wire as freelanderuk had said.as per the mod on the solar system a dual controller is the correct fix .if your going to do a job do it correctly or not at all

Roopert wrote:Not sure if I'm misunderstanding what you have done, but if you are putting two solar chargers in series, I'm surprised that you are getting any solar charging at all! So I'm probably misunderstanding.

The reason is that most solar chargers are built with an assumption that the solar panel output will be in the range 19-26V (roughly). The output of a solar charger operating into a nominal 12V system should never exceed around 15V, so it would seem impossible for the output of one to reach the minimum operating threshold of the second! So I must be misunderstanding!

I should add that I have never tried it, so in real world conditions I don't know. I would expect to get a small amount of charge through, but I wouldn't expect it to be able to get anywhere near the panel's capacity.

It's a mystery for me too but it's working and I will try to explain better.
It's not entirely correct that I am using the 2 solar chargers in series.
The first one, Victron MPPT 75/12 is has 6 terminals, pv+/pv-, battery+,battery- and load output+/load output -

Normally all load is managed from the battery (or busbar in the battery) but by activating load output, it can generate up to 15A / 12V.
The output can be configured with different algorithms (i.e. BatteryLife)
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I have investigated and this output cannot be used to directly charge a battery (i.e. vehicle battery) on top of that, inside the EC500 there is a poly fuse that can max take 6A if I am not wrong, so I could risk frying it with a direct connection.
By connecting the Victron load output to the input of the original Sargent solar controller, it seems that the input is strong enough to enable charging of the Vehicle battery
I remember reading that the load output terminals are connected directly to the battery terminal but managed using the settings of the app.

I must admit, I just tried and it worked, I cannot see at this point if there are negative consequences

glyne lock wrote:gobsmacked
your wiring the white cable going in from the roof normally goes to a joint and into the lovely sargent wiring and down to the solar controller .this I always put a new complete wire from panel down to the solar controller so now has no joints that cant be seen and the correct wire as freelanderuk had said.as per the mod on the solar system a dual controller is the correct fix .if your going to do a job do it correctly or not at all

Hi glyne lock,

I am not sure I understand your comment. The wiring from the roof into the Victron MPPT 75/15 has been fixed a long time ago and it works perfectly.
My last post is about something completely different :-)

the wiring from the solar panel when fitted by A/S goes to a joint under the roof and into the sargent wiring and then to the solar controller. the wire in the roof down to the solar controller is smaller then the white wire on the roof of your van .lots of things may work but is the wire able to take the load and the joint getting hot from the extra load put on it .myself I fit the correct wire as to the load as I don't want a claim put against myself for damage from work I have done when fitting panels to people campers

glyne lock wrote:the wiring from the solar panel when fitted by A/S goes to a joint under the roof and into the sargent wiring and then to the solar controller. the wire in the roof down to the solar controller is smaller then the white wire on the roof of your van .lots of things may work but is the wire able to take the load and the joint getting hot from the extra load put on it .myself I fit the correct wire as to the load as I don't want a claim put against myself for damage from work I have done when fitting panels to people campers

Thank you, as I mentioned back in October, the choice of keeping the existing wire was a conscious one, after verifying the cable gauges at both ends with Sargent and opting for a serial panel connection to keep the amp low. That installation is done and works as it should.
It sounds great that if someone commissioned a job, you ensure yourself from claims by installing the proper wire. Me being my own customer I have opted for this pragmatic solution and I am happy about it. I can always pull a new wire when/if I feel so. ;-) 

Still, this is an old subject that has been discussed long ago. I would appreciate more to get some feedback on today's update if you happened to have one.

The correct way to charge the batteries is a dual controller and the old controller is not able to take the power that could now come from your panels

glyne lock wrote:The correct way to charge the batteries is a dual controller and the old controller is not able to take the power that could now come from your panels

What do you mean with "the old controller is not able to take the power that could now come from your panels". Please explains since as I have shown and explained, it actually working.

Yes, of course, if one has installed an MPPT with two battery outputs, that is one way to do it, not the only correct way to do it.
As far as I can see there are 4 ways to charge a vehicle battery:
1) While driving
2) From a charger that has an auxiliary trickle output while connected on mains (our Victron EasyPlus has it but I have not wired it yet in that way)
3) Fro Battery to battery using something like Battery Master (or similar) or even DC to DC converter
4) MPPT with double output for 2 batteries as you mention

The solution I have implemented is not standard but actually discussed with Sargent. They were unsure if the load output of the Victron could activate the PV input of the old controller and suggested trying. I did and it worked. As much as yesterday, it was able to revive a completely flat vehicle battery.
The question is not if it works but if there are an unwanted side-effect that you can spot or predict  based on knowledge and facts

gobsmacked wrote:
By connecting the Victron load output to the input of the original Sargent solar controller, it seems that the input is strong enough to enable charging of the Vehicle battery

It's interesting - I had always assumed that there would be a voltage threshold below which charging would be severely limited. But perhaps this is one case where the simplicity of the Sargent-supplied controller is a benefit. It will be interesting to see what peak current you get from this configuration, into the vehicle battery, when the panel is in full sunlight.

Roopert wrote:

gobsmacked wrote:
By connecting the Victron load output to the input of the original Sargent solar controller, it seems that the input is strong enough to enable charging of the Vehicle battery

It's interesting - I had always assumed that there would be a voltage threshold below which charging would be severely limited. But perhaps this is one case where the simplicity of the Sargent-supplied controller is a benefit. It will be interesting to see what peak current you get from this configuration, into the vehicle battery, when the panel is in full sunlight.

I will take a photo of the EC480, MPPT and Shunt in full sunlight (when the Scandinavian weather allows it) and post it here :-)

Another little update on the build is a plexiglass cover for the DC distribution board.
While I was very happy with the distribution board compact design and fusing system, I was very nervous about its exposure to accidental shortcircuits.
Now the entire board and cables connection so covered with a plexiglass enclosure that allows ventilation and quick access to the main battery switch
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That's a very sensible precaution! I've always liked PMMA sheet for things like that - quite good fun to heat bend enclosures yourself. The adhesives are expensive though...

Again from me well done gobsmacked, where you lead A-S is nowhere. They are now selling motorhomes without any solar panel. We need to go green, they should be selling van's that aren't dependent on EHU or LPG. Soon all vehicles sold will have to be electric powered, fuelled from renewable sources. A-S have a long way to go. I encourage other motorhome manufacturers to sell the greener products that A-S currently doesn't.

Relaxez-Vous wrote:Again from me well done gobsmacked, where you lead A-S is nowhere. They are now selling motorhomes without any solar panel. We need to go green, they should be selling van's that aren't dependent on EHU or LPG. Soon all vehicles sold will have to be electric powered, fuelled from renewable sources. A-S have a long way to go. I encourage other motorhome manufacturers to sell the greener products that A-S currently doesn't.

Thank you!
I agree completely, it would be so easy for A-S to build and sell motorhomes with more modern, open and future-proofed electric systems.

Hi Gobsmacked,

I've just found your thread after hours trawling to find out how to deal with the Sargent equipment when upgrading to Lithium power.  My problem has been how to disconnect redundant elements of the EC700/500 without loosing all the features e.g tank levels. Also replace the PX300 with new charger or combined charger/inverter like Easyplus.

From reading your posts it seems you do not have a DC-DC charger, something that seems to be essential if the base vehicle's alternator is 'smart'. My 2020 Kemerton is Euro6 (Adblue system)so I have assumed it has a smart alternator.

I just want a more reliable off-grid capacity (up to 3 days) but not needing any real AC power so am looking at 100Ah LIFEP04, DC-DC charger, Smart Solar MPPT and a suitable replacement for the PX300, maybe get an inverter later.

Any comment/advice would be much appreciated. I note that your van already had a 100Ah LIFE P04 when you bought it. Was all the other electrical equipment still AS standard? If so did the LiP04 work OK? Do you think 100Ah is a false economy if upgrading all the other components?

Many thanks

Andril1954 wrote:Hi Gobsmacked,

I've just found your thread after hours trawling to find out how to deal with the Sargent equipment when upgrading to Lithium power.  My problem has been how to disconnect redundant elements of the EC700/500 without loosing all the features e.g tank levels. Also replace the PX300 with new charger or combined charger/inverter like Easyplus.

Hello Andril1954,

I would definitively suggest the Easyplus or if you have space for it, the slightly bigger EasySolar . Basically the AC cable that goes into your EC700 should be instead routed into the EasyPlus/EasySolar AC IN and the AC0 out routed back to the EC700.
This is the most basic connection. Then would you wish some inverted power (i.e. the AC sockets in the van) you disconnect the relevant AC out cable from behind the EC700 and instead attach it the AC1/AC2/AC3 out of the EasyPlus

if you go for EasySolar, it has connectors for 3 PV arrays. I would suggest you to wire 2 for the roof an wire 1 to an Anderson plug accessible on the side of the van. In that way you could attach a portable PV panel and place it were best suited according to sun agle

Andril1954 wrote:
From reading your posts it seems you do not have a DC-DC charger, something that seems to be essential if the base vehicle's alternator is 'smart'. My 2020 Kemerton is Euro6 (Adblue system)so I have assumed it has a smart alternator.

You should start verifying if you do have a smart alternator.
Have a look at this if it helps.
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If you do have a smart alternator, you should definitively consider installing a Orion DC-DC. But you will need to disable the "engine on" signal that comes into the EC700. You should contact Sargent about this because it has implications.
Here is a link to EC700 dealers guide with all the schematics you might need

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Andril1954 wrote:
I just want a more reliable off-grid capacity (up to 3 days) but not needing any real AC power so am looking at 100Ah LIFEP04, DC-DC charger, Smart Solar MPPT and a suitable replacement for the PX300, maybe get an inverter later.

Not sure what your needs are but you should investigate your power usage / solar expectation and so to decide if 100Ah is sufficient. We have installed 200Ah.

As you can see from this thread, we have installed the EasyPlus and the MPPT 75/15 (that has to be sized based on the size of expected solar input)

Andril1954 wrote:
Any comment/advice would be much appreciated. I note that your van already had a 100Ah LIFE P04 when you bought it. Was all the other electrical equipment still AS standard? If so did the LiP04 work OK? Do you think 100Ah is a false economy if upgrading all the other components?

We purchased our van used and the previous owner had changed the battery and installed the 100Ah LiFeP04. The rest was completely standard.
In my opinion, when considering offgrid, power storage is the extremely important. I would definitively suggest you to consider 200Ah if not 300Ah

The most tricky part in my opinion is installing the DC to DC (if needed because you have a smart alternator). But is not a big deal but you need to identify the correct wire and either cut it or place a switch on it.
Afterwards, you can create your DC-DC installation from the vehicle battery to the new LiFeP04 battery.
There are some features you will loose by cutting the "engine on" signal into the EC700. Sargent will be more specific about them


Many thanks