What I have described is fitting the shunt on the negative side. You can fit it on the positive side but I prefer (as do Fairline) to fit it on the negative side. Either works; it's a free choice. Usually it is physically easier on the negative side.
Ah ok, the mastervolt battery monitor also has 2 secondary monitors for the engine starters and the 12v battery, so this might be part of the reason Fairline fit it on the negative.The Victron Battery Monitor, which has been mentioned a lot, incorporates a secondary voltage monitor (that I use to monitor my engine start bank).
In this case, the shunt HAS to be on the negative or it won't monitor the secondary - in this case, there are then 2 positive wires - one goes to the house bank and one to the secondary (engine) bank.
I fitted my shunt directly onto the battery bank's negative terminal using a short busbar.
Ah ok, the mastervolt battery monitor also has 2 secondary monitors for the engine starters and the 12v battery, so this might be part of the reason Fairline fit it on the negative.
BUT those are not proper battery level monitors, on either the mastervolt or the victron, so one should not get too excited about them. They measure voltage and from that they deduce state of charge, which isn't the same as actually measuring the Ah flowing in/out of the batteries
Out of these three, Monocrystalline is the oldest, most efficient and reliable technology.
Another consideration is that all panels become less efficient the hotter they get.
Anything stuck down (Stick on and Semi Flexible) will get hotter than panel ones where the air can freely circulate underneath.
So I am currently looking at rigid panels.
I think I can fit them in such a way that they can be removed and stored in my storage shed in Spain during the winter months.
I have a preferred panel manufacturer and it seems that I could get about 630 watts on the eyebrow without them looking out of place.
My choice of charging system at the moment is Victron's MPPT controller.
I think I can get the wiring from the panels to the controller to within 3m and the wiring between the controller and the batteries to within 4m.
At the moment, this is definitely a project for this season.
No kit bought yet but we are already considering when we will drive it out to Spain.
A Q John:
IS there any meaningful way of measuring the Ah flowing I/O on the service bank without breaking the bank? TBH, I'd not bother with the engine bank as its job is way too easy to worry me...
.
similar conclusions drawn here Mike,
care to tell us which is your preferred panel manufacturer? I was told to avoid the Korean and various dubious Chinese ones.
I'm trying to finalize on the panels, was planning on two 99X160 280W 60cell mono, but I see I can get Luxor LX345-P 99X198 72cell 345W (but substantially more expensive at 360euro each)
Got to devise a way of keeping them at least 30mm above the coachroof in order to let air circulate.
3 and 4m lengths are no issue I recon, just get v.good quality and slightly oversize cables to avoid V drops I guess - at least that's what I plan to do.
cheers
V.
Vas the Victron BMV 700 battery monitor is around 150 euro (online) including the shunt,
imo a very usefull instrument in any setup, it integrates all the currents that go in and out your battery's.
and display's the % charge of the battery bank.
this would probably show that you have drained the battery's too deep, or didn't charge them full enough...
I have two of them, one for each bank separately,
and i have arranged a working mode that allows the relay contact in the battery monitor from the domestic bank to start the generator,
mainly used when going to bed; the generator switches automatically on, early in the morning,
moment is depending on how long we had the UWL's "on" the night before ;-)
Can you post a link to the data sheets for those panels - I couldn't find them.
I quite like these from LG - I would probably install 2 panels.
Brochure
http://www.lg.com/us/commercial/documents/lg-commercial-solar-brochure-lgneon2.pdf
Datasheet
http://www.lg.com/us/commercial/documents/lg-solar-spec-neon2-lg315n1c-g4-150901.pdf
I had a chat to a Vicrton dealer at the Paris Boat Show.
He confirmed some of my design criteria but I still need to ask some more questions.
The decision to wire in Series vs Parallel isn't that simple.
If I wire the LG panels above in parallel, the voltage output might not be enough to start the Victron controller (as it needs at least 5v more than the battery voltage to start - my batteries are wired in 24v banks).
So, I would need to wire them in series but then there is a danger that a shadow over one cell will stop the whole array - the solution seems to be diodes installed within the panels so that current can flow through a cell when it isn't producing power. It seems to me that the cells in the LG panels are wired in several "chains" - each chain with its own diode so this might work.
I'm going down to the boat at the end of this month to do some final measurements - then maybe order up some kit and try it out.
last on the eco line is the one I'm talking about:
http://www.luxorsolar.com/download.htm
I noticed there are three diodes in each, dunno if that's enough.
Regarding the series or parellel, they seem to produce 20% more than the LGs, open circuit is 46 vs 40, mpp V is 38 vs 33, so maybe they are more suited to parallel wiring? That's what I was planning to do tbh, but I still have the SS fabricator on standby in order to decide and actually get the panels I want so he can start building the hardtop around them!
what do you think?
BTW - the way I was going to wire the system, I would keep my old Vicrton Battery Monitor in the circuit monitoring the input and output of the battery bank.
The Victron MPPT controller would then provide a separate output of solar power collected.
I agree the Victron's bluetooth interface feature to a smart phone should provide a good history of solar power collected.
But leaving the existing battery monitor should also provide an overall status of discharge and then charge from both the generator and the solar array.
will discuss the details also with Victron.
I've only glanced at the details in your link.
I will have a good look later.
From the quick look, that last one is too long for my eyebrow - the 300 watt one would fit though.
I take your point about the voltage but the overall power/sq m seems better on the LG panels
I'll have a good look though.
Mike,
the large ones are out as I can only order a palette of 10
No way!
further, there's an issue on the mppt needed, seems that for two of those you need to get a 30A one (as per the Victron XL sheet) which costs almost as much as the a panel!
Waiting for some new quotes and will come back with actual models/specs and prices
cheers
V.
This was the MPPT that I was looking at.
http://www.es-store.co.uk/product_d...lar-Charge-Controllers&cat_id=96&show_menu=27
My logic was 630 watts divided by 24 volts = 26 amps
Panels in series but I don't think thats important when sizing the MPPT.
I need to talk to a Victron expert before I actually order though.
Nothing will be ordered until I've been out to the boat and checked the measurements at the end of this month.
correct,
only useful option for us is the 100/30, we could easily do with 75/30, only there isn't one. I guess you are aware of the XL sheet for the calculations? I added the 345W panels and did the calcs, will do the same with the ones I'll get beforehand:
https://www.victronenergy.com/upload/software/VE-MPPT-Calc-2_2.xlsx
cheers
V.