New Dual Battery Solar Regulators for 2020

[Alan Andrews]

I've just had a look.

Screwfix do not have anything.

I suggest going to a very good electrical trade store with your plate and seek guidance on what will fit.

This is the type of extension I was thinking of.

You'll need to confirm dimensions.

https://www.amazon.co.uk/dp/B00NGT1WTA/?tag=vwcalifornia-21

 

[NRDSRFR]

For the benefit of anyone wanting a compact, split charger (leisure + starter) I can confirm the Votronic panel can sit flush if you’re very careful about positioning it!

Ahead of panel arriving this week from Roger, I started my install including getting the status panel connected to the controller. Found a use for some old Velcro tape, should hold it in place with no drilling in case I get a new van one day and easy to remove to adjust wiring.


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[NRDSRFR]

Just wanted to say thanks to everyone on these forums! Finished my install today finally.

I like the small size of the Votronic unit, it will have almost no impact on my cupboard space.


Couple clips and duct tape allow the blind to close fully



For anyone who has the security bolts holding the relay for the starter battery connection, this set contains the bit you need to remove them: https://www.screwfix.com/p/hex-shank-mixed-security-bit-set-33-pieces/2840v?_requestid=408409



All done



I do have a general question...yesterday when the sun came out I was getting over 4 Amps of power, but today it's even sunnier but I'm only showing 0.1A. I would have thought it's because the batteries are full, but the status panel is showing 12.3 V with nothing turned on. I would expect it would be higher before the charger stops supplying charge and dumps the energy?

 

[Loz]

I expect your batteries are now charged and the unit has lowered the charge to a float load so less wattage required.

 

[NRDSRFR]

I expect your batteries are now charged and the unit has lowered the charge to a float load so less wattage required.

I’m in Devon, fridge went off this morning so spun the van so the panel points south, panel showing 10.8 V , so I should be getting full juice from this thing but only getting 0.1A / 1 W.

Anyone have any ideas why it’s so poor? I looked at the manual for my regulator and I’m not sure if the display is gross power from the panel or net including the fridge which is back on. There is not a cloud in the sky now so surely this can’t be the best it does


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[Vagophile]

It's a cloudless blue sky here on my drive My 100W solar panel is lazing on the Cali roof (flat). The fridge is on setting 4 maintaining about 10 degrees centigrade.
These are readings taken at noon.

Input



Leisure batteries


Leisure battery current


Starter battery


I'm happy.
Shame these weren't taken from some exciting exotic location!

 

[WelshGas]

I’m in Devon, fridge went off this morning so spun the van so the panel points south, panel showing 10.8 V , so I should be getting full juice from this thing but only getting 0.1A / 1 W.

Anyone have any ideas why it’s so poor? I looked at the manual for my regulator and I’m not sure if the display is gross power from the panel or net including the fridge which is back on. There is not a cloud in the sky now so surely this can’t be the best it does


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Is the panel clean, no bird splatter?

 

[Loz]

I’m in Devon, fridge went off this morning so spun the van so the panel points south, panel showing 10.8 V , so I should be getting full juice from this thing but only getting 0.1A / 1 W.

Anyone have any ideas why it’s so poor? I looked at the manual for my regulator and I’m not sure if the display is gross power from the panel or net including the fridge which is back on. There is not a cloud in the sky now so surely this can’t be the best it does


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You should be getting 30-40w in that condition. Check the connections.
Also,(looking at your original picture) try temporarily moving the earth from the seat base directly to the battery negative, because the seat base is painted and unless you have cleaned off the paint on the base where the nuts tighten, you may not have a good enough earth.
I say temporarily as you will still need a good chassis negative as you are using one negative for both batteries.

 

[NRDSRFR]

Is the panel clean, no bird splatter?

It’s clean. Not sure what’s going on, I got over 4 Amps in the drive before my holiday, so it tested fine. Didn’t bring a multimeter but someone on the campsite has one if I can be asked to start fiddling around


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[NRDSRFR]

You should be getting 30-40w in that condition. Check the connections.
Can you disconnect the panel and measure the open circuit voltage?

If I just disconnect the pigtail lead on the panel and stick multimeter probes into the end would that show the wattage coming directly through the panel?


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[Loz]

If I just disconnect the pigtail lead on the panel and stick multimeter probes into the end would that show the wattage coming directly through the panel?


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It will show voltage across the cables, there will be no wattage as there will be no load.

Also,(looking at your original picture) try temporarily moving the earth from the seat base directly to the battery negative, because the seat base is painted and unless you have cleaned off the paint on the base where the nuts tighten, you may not have a good enough earth.
I say temporarily as you will still need a good chassis negative as you are using one negative for both batteries.

 

[NRDSRFR]

It will show voltage across the cables, there will be no wattage as there will be no load.

Also,(looking at your original picture) try temporarily moving the earth from the seat base directly to the battery negative, because the seat base is painted and unless you have cleaned off the paint on the base where the nuts tighten, you may not have a good enough earth.
I say temporarily as you will still need a good chassis negative as you are using one negative for both batteries.

I’m not sure what you mean. I think I connected the regulator to the leisure battery positive and negative terminals and just a positive lead that goes under the front seat for the starter. I don’t think I’ve connected anything to an earth.


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[Pd.]

Looking at your picture I am assuming that the leisure battery connection are made at the rear leisure battery rather than under the seat. From my T5.1 install the engine battery lead was on the LHS of the reley, but I can't fully remember as I made a lot of alterations in that area due to having a bluemotion when I installed solar.

I have an epever unit and it seems to work fine although as Roger says the bluetooth is pretty useless. Is it possible tht the connections are wrong on the victron unit ie leisure and starter feeds crossed?

 

[NRDSRFR]

So I’ve borrowed a multimeter. The panel was putting out just over 20V. I turned off the fridge and with the multimeter being in 100th’s I could see the voltage going up slowly from 10.81, 10.82 now it’s 11.1 so it’s working but seemed to be a losing battle with the fridge on.

I’m still not sure why at just over 20V I am not seeing close to 2A on the panel but at least with fridge off I can observe some charge

¯\_(ツ)_/¯


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[Alan Andrews]

So I’ve borrowed a multimeter. The panel was putting out just over 20V. I turned off the fridge and with the multimeter being in 100th’s I could see the voltage going up slowly from 10.81, 10.82 now it’s 11.1 so it’s working but seemed to be a losing battle with the fridge on.

I’m still not sure why at just over 20V I am not seeing close to 2A on the panel but at least with fridge off I can observe some charge

¯\_(ツ)_/¯


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I think we need a clear explanation from Roger Donoghue please regarding what is normal and any nuances regarding the expected controller readings.

 

[Roger Donoghue]

Hi all - I don't get email notifications of most posts on here so only see this when I'm quiet and doing a forum check up.

A 100w slim panel produces a tested 5.4amps max (indicated 75 watts - you lose some to heat etc).

It will only do this when the battery is low enough to take a full bulk charge- easily achievable by turning on a fridge.

Once the battery approaches full the charge will drop to as low as 0.1amp. This is the float charge (maintenance charge - the same charge as when you are on hookup "conditioning" your battery once a month as VW recommend - which you no longer need to do when you have solar).

If you have doubts about your solar performance then point the panel at the sun (lift the roof) and turn your fridge on (make sure you actually hear the fridge rumble into life - open the fridge door to prompt this if you need to). You shoudl see the Amps climb to around 4 amps, which is what the fridge draws. This is in summer time, clear sky. Expect it to reduce with clouds, and severely in winter.

You can meter a solar panel for voltage (should be around 20v disconnected). You can also meter it for short circuit amps, but you need a meter than can handle up to 5.5 amps across the current measuring circuit. Decent meters do this but the basic ones usually max out at a few hundred milliamps.

 

[Alan Andrews]

Hi all - I don't get email notifications of most posts on here so only see this when I'm quiet and doing a forum check up.

A 100w slim panel produces a tested 5.4amps max (indicated 75 watts - you lose some to heat etc).

It will only do this when the battery is low enough to take a full bulk charge- easily achievable by turning on a fridge.

Once the battery approaches full the charge will drop to as low as 0.1amp. This is the float charge (maintenance charge - the same charge as when you are on hookup "conditioning" your battery once a month as VW recommend - which you no longer need to do when you have solar).

If you have doubts about your solar performance then point the panel at the sun (lift the roof) and turn your fridge on (make sure you actually hear the fridge rumble into life - open the fridge door to prompt this if you need to). You shoudl see the Amps climb to around 4 amps, which is what the fridge draws. This is in summer time, clear sky. Expect it to reduce with clouds, and severely in winter.

You can meter a solar panel for voltage (should be around 20v disconnected). You can also meter it for short circuit amps, but you need a meter than can handle up to 5.5 amps across the current measuring circuit. Decent meters do this but the basic ones usually max out at a few hundred milliamps.

I have had the same doubts.

I contacted Roger who answered all of my questions and quelled my concerns.

I then did exactly as Roger suggests here to test the kit. It worked just as Roger describes.

 

[NRDSRFR]

I got contacted by photonic universe who sold me the Votronic MPPT controller. I haven’t managed to test the voltage at the battery directly compared to the unit as they recommended to ensure my wiring isn’t losing any power (I need to clear out the boot to get to the battery!) but I CAN share that apparently the unit uses a small amount of power from the batteries since it’s more stable than power from the panel. The unfortunate result according to them is that if the batteries get really drained the unit will shut down and not charge them from dead, even if the panel is providing ample voltage. They said more expensive units might be able to pull this off (I thought mine WAS expensive!). What’s odd is that I’m pretty sure they said 11.1V was around this very low threshold but my post from holiday I saw the voltage very slowly ticking UP from 10.8V, so it seemed to be working at such a low voltage. I feel like I post more questions than answers...

I’ll wait for some direct bright sun and retest with the fridge open, with at least 11.5V to ensure the controller is happy, and will triple check the battery with a multimeter against what’s indicated on my panel AND I’ll shift my roof box which creates a TINY shadow.

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[NRDSRFR]

I had the van on charge all night before I head off today. I was packing the van and incidentally noticed that suddenly I’m getting three times the power as I ever have from the panel

That’s more like it!

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[MarkStitson]

I was installing the Epever Doa Racer charger and an MT11 display in my T6.1 and noticed that the top shelf in the rear wardrobe is now fixed permanently.

This means you can't run the MT11 cable at an angle and I needed to extend the MT11 cable with a terminal strip.

 

[soulstyledevon]

I was installing the Epever Doa Racer charger and an MT11 display in my T6.1 and noticed that the top shelf in the rear wardrobe is now fixed permanently.View attachment 86743

This means you can't run the MT11 cable at an angle and I needed to extend the MT11 cable with a terminal strip.

View attachment 86744

Ive not installed it yet.
But I’ve acquired the Bluetooth module instead of having a permanent display.
I had the same display as you, but never installed it, looks good.

 

[Roger Donoghue]

I mount the Epever Duo sideways. Keeps the cables all tidy out of the way, and means the MT11 cable is long enough without extending.

 

[California_Ocean]

For those who want to go down the Victron route and still want to charge the 2 leisure batteries and the starter battery, I fitted this to my boat which also has a bank of "house" batteries and a seperate starter.

Cyrix Battery Combiners - Victron Energy

Automatically connect batteries in parallel when one of them has reached a pre-set voltage using the Cyrix Battery Combiners. Find a dealer near you.

www.victronenergy.com

It also has a neat feature where you can do a battery-combine for 30 secs with a button press ... very useful if the starter battery is dead for some reason.

I'm only just starting the solar journey with my camper van having fitted a system to my boat a few years ago, so not certain yet over the interaction with the vans own electronic systems ... would be good to know if anyone knows why a battery combiner like this would be a bad idea on a van.