Thank You - New Power System

Hi folks,
I just wanted to share my utmost gratitude to the many people who have posted useful guides on here, replied to detailed questions and even PM’ed me advice & encouragement. 

I’m just back from 4 weeks touring the northern half of the island of Ireland - and did not need Electric Hook-Up once! In our 2019nNeuvo, we have your standard electrical needs plus a 1000W inverter for hairdryer, portable projector and well-used e-bikes. We already had a 105Ah Lithium battery, but previously we found we needed hookup every 3~4 days at least. This new set up was a game-changer, as we stayed on sites a grand total of three nights, for laundry or water/waste facilities. 

In summary I added a second 90W Victron solar panel (to the AS installed 80W one), a new Victron Single channel MPPT controller and a Sterling 25A bi-directional B2B, completely bypassing the Sargent EC700 system. This was not super high capacity additions, but I watched with glee as the battery was charged to 100% day after day, either by Solar, a little driving or a combination of both. Bonus points for being able to charge the ebike batteries from the inverter whilst driving. It all came in at around £450 (but that included lots of spare cables, fuses, relays, etc). 

I’m a relatively competent DIY-er, but had never done much 12v electrics. The information and helpful people on here made all the difference. 

So thanks again  

Rgds,
Heeb

Did you leave the 80W panel and Sargent solar controller as is or did you rewire that through your new Victron controller therefore bypassing the EC700?

Surprised we didn't meet!
Also back from North half WAW.
Also didn't use ehu for the 2 weeks away.....

Ditto. Not long back from two weeks touring the northern half of WAW + Antrim Coast Road (anticlock). We dodged Ian by diverting to Boyle for gas! The only time we used a hook up (and a site) was when we had a minor engine problem and spent the weekend waiting for a part (but where better to do that than in Castlerock?)

Will you be applying your new found 12 volt skills to separating out all your essential DC services from the Sargent system to avoid a calamitous overall power outage like we had when we first bought our van? The only functions our Sargent EC700 now serves are the step and the water tank gauge, both to be dealt with soon! Otherwise it stays turned off!

Caraman wrote:Did you leave the 80W panel and Sargent solar controller as is or did you rewire that through your new Victron controller therefore bypassing the EC700?

Yep, removed Sargent controller completely. 

I dithered quite a bit about Series or Parallel for the two panels, having read pros & cons. Ended up just doing parallel, but as I’m using Wago connectors to make the connections inside the van, I’m toying with the idea of leaving them accessible, so I could flip around depending on conditions.

Edit: I don’t mean switching on the hoof - more like Series for Northern Europe winters; parallel for Central/Southern Europe summers.

IanH wrote:Surprised we didn't meet!
Also back from North half WAW.
Also didn't use ehu for the 2 weeks away.....

We were saying there didn’t seem to be a lot of vans on the road! We went from Malin Head round to Galway. We were so lucky with the weather and the scenery was jaw-dropping. The last week NE, Rathlin, The Gobbins and a bit of GoT!

It did mean we got some really good park ups completely to ourselves. Although not sure anyone else was crazy enough to stay overnight on Minaun on Achill (I’d recommend it with caution - we had the most amazing sunset, then had to drive down in thick fog in the morning!)

The Bargee wrote:Ditto. Not long back from two weeks touring the northern half of WAW + Antrim Coast Road (anticlock). We dodged Ian by diverting to Boyle for gas! The only time we used a hook up (and a site) was when we had a minor engine problem and spent the weekend waiting for a part (but where better to do that than in Castlerock?)

Will you be applying your new found 12 volt skills to separating out all your essential DC services from the Sargent system to avoid a calamitous overall power outage like we had when we first bought our van? The only functions our Sargent EC700 now serves are the step and the water tank gauge, both to be dealt with soon! Otherwise it stays turned off!

We used 3 sites in the month, but didn’t pay for EHU - it was more desperation for facilities! Our total expenditure on overnights was £89! The new kit is already paying itself back, if not already has!

Don’t think I’m quite that brave. I’ve found at least two bodge jobs and one case of wiring with reversed polarity, so I’m not entirely convinced that I can build on these foundations with confidence - and I’m not going to rewire the whole van!

Malin Head!! (Only parking space left when we arrived, so went for it!!)

We too were surprised how quiet the roads were, and specifically how few motorhomes were around. We thought Achill Island was fantastic but didn’t stop the night. I suggested stopping at Slievemore but the combination of 100 derelict homes and a cemetery were too much for my wife! Just too many ghosts

I haven’t “re-wired my van.” Just fitted a normal switch panel and fuse box, then intercepted almost all the outputs from my CPU and wired in bypasses at the new fuse box. Then pulled all but one fuse in the CPU fuse box. Quite easy really once you have identified the cables and fuses, which do not conform fully with the Sargent wiring diagrams. Where I have fitted new components, e.g. Shurflo pump, I have rewired with more suitably sized cable, and the same will happen when or if the boiler and fridge are replaced.

Heebson wrote:
Yep, removed Sargent controller completely. 

I dithered quite a bit about Series or Parallel for the two panels, having read pros & cons. Ended up just doing parallel, but as I’m using Wago connectors to make the connections inside the van, I’m toying with the idea of leaving them accessible, so I could flip around depending on conditions.

Edit: I don’t mean switching on the hoof - more like Series for Northern Europe winters; parallel for Central/Southern Europe summers.

Thanks.  Did you use the existing 80W panel cabling to the controller and then connect new cabling from the 90W in parallel at the controller?

My understanding is that two panels connected in parallel to the same controller with one input port should each have the same voltage output (which yours' presumably do) and two panels in series should each have the same current output, which is unlikely if the panels are different in size or age or one is partially shaded and the other is not.

Caraman wrote:
Thanks.  Did you use the existing 80W panel cabling to the controller and then connect new cabling from the 90W in parallel at the controller?

My understanding is that two panels connected in parallel to the same controller with one input port should each have the same voltage output (which yours' presumably do) and two panels in series should each have the same current output, which is unlikely if the panels are different in size or age or one is partially shaded and the other is not.

Yes, used the existing cable from the original panel. The original cable is a single, dual core cable, so I couldn’t really make the joins on the roof - I.e. if I cut & split the cable, I wouldn’t be able to get a watertight seal on the MC4 connectors. Serendipitously, this means I can alter the wiring pattern at a later date easily with Wago connectors and a bit of spare cable. 

I tried in vain to get the panel spec from AS, except that it was 80W. My understanding is that it’s not so much the voltage or current outputs need to be the same, it’s just that you’ll be throttled to the lowest value - which for my setup, made getting a more powerful panel pointless. The attraction with Series as I understood it, was that in northerly climes (low sun angle), you’d start picking up power as soon as at least one panel was getting sun. 

I’ll happily be corrected - I absorbed an awful lot of information in a short time and without doing this regularly, the knowledge slips away quickly!

Heebson wrote:

Yes, used the existing cable from the original panel. The original cable is a single, dual core cable, so I couldn’t really make the joins on the roof - I.e. if I cut & split the cable, I wouldn’t be able to get a watertight seal on the MC4 connectors. Serendipitously, this means I can alter the wiring pattern at a later date easily with Wago connectors and a bit of spare cable. 

I tried in vain to get the panel spec from AS, except that it was 80W. My understanding is that it’s not so much the voltage or current outputs need to be the same, it’s just that you’ll be throttled to the lowest value - which for my setup, made getting a more powerful panel pointless. The attraction with Series as I understood it, was that in northerly climes (low sun angle), you’d start picking up power as soon as at least one panel was getting sun. 

I’ll happily be corrected - I absorbed an awful lot of information in a short time and without doing this regularly, the knowledge slips away quickly!

Thanks and understood.  I am no expert either and am only as good as what I have read and been told.

The Bargee wrote:............... The only functions our Sargent EC700 now serves are the step and the water tank gauge, both to be dealt with soon! Otherwise it stays turned off!

The EC700 by rights, and everything that is logical shouldn't be connected with the step - I know it is from the factory but if you chuck out the push-to-make step switch and substitute a three way 'up-step-out / centre off / down-step-in' standard caravan step switch you can bypass the microprocessor in the EC700 and you don't even need to add any wires. They are already there, assuming you have an ?is it EB44 or EB45? tow bar fuse panel you just relocate the existing wires to the tow bar panel. Assuming you arent going to fit a tow bar you have done away with another Sargent non-optional standard fault-prone bit of unnecessariness. You just need to get the three way switch and look up the wiring diagram for the step and it's blooming obvious that it should have been wired with a three way switch in the first place. The auto-retract still works when the ignition is turned on. I had wondered about writing a feature on it for MMM but haven't got round to it. Perhaps I'll get a round tuit for Christmas.

Caraman wrote:
Thanks.  Did you use the existing 80W panel cabling to the controller and then connect new cabling from the 90W in parallel at the controller?

My understanding is that two panels connected in parallel to the same controller with one input port should each have the same voltage output (which yours' presumably do) and two panels in series should each have the same current output, which is unlikely if the panels are different in size or age or one is partially shaded and the other is not.

My theory is that as each cell in a panel must be wired in series to the next cell in the panel, then the logical way to add another panel would be to wire it in series to add all the cells together as they would be in a single eg. 200W panel.
My other theory is that if your motorhome is going to spend most of its life in the northern hemisphere or at least in northern Europe it won't ever have the full benefit of a blazing sun vertically overhead, and therefore at times the voltage from each panel might be less than say 13 or 14v. Therefore to get any charging current at all from them they would need to be wired in series in order to get more than the voltage required to shove some current into the battery.
That's my tuppence worth . . . .

....and I am an ex spurt retired electronics engineer.  (An Ex Spurt is a drip of water under pressure.)

gassygassy wrote:
The EC700 by rights, and everything that is logical shouldn't be connected with the step - I know it is from the factory but if you chuck out the push-to-make step switch and substitute a three way 'up-step-out / centre off / down-step-in' standard caravan step switch you can bypass the microprocessor in the EC700 and you don't even need to add any wires. They are already there, assuming you have an ?is it EB44 or EB45? tow bar fuse panel you just relocate the existing wires to the tow bar panel. Assuming you arent going to fit a tow bar you have done away with another Sargent non-optional standard fault-prone bit of unnecessariness. You just need to get the three way switch and look up the wiring diagram for the step and it's blooming obvious that it should have been wired with a three way switch in the first place. The auto-retract still works when the ignition is turned on. I had wondered about writing a feature on it for MMM but haven't got round to it. Perhaps I'll get a round tuit for Christmas.

….. and I will catch up with you on that “outstanding” matter of the step when I get a chance GG !

gassygassy wrote:
My theory is that as each cell in a panel must be wired in series to the next cell in the panel

I don't think that's true of bigger panels these days - I think they all tend to be multiple "strings" arranged in parallel - so each panel will be a combination of series and parallel, within the panel itself. One of our failed panels first went to roughly half the output power (but roughly the right voltage) which seems to correspond to one of the internal "strings" failing.

But I agree with your conclusions anyway - that if you're going to spend significant amount of time up north, series is probably the way to go. When I upgrade to two panels (needed to feed my very power-hungry compressor fridge) I'll probably put a connection point in that will allow for either (and also act as a test point for regular checks that both panels are behaving correctly).