Low budget 48V system components?

[bvdb]

Originally Posted by Franziska

Hi,


a few years ago the forum was a very helpful resource for putting together our OLD 12V LiFePo4 system.


We're in a different boat now, but are still on the low budget side. Still we need to add LiFePo4 and solar again and now also have two Diesel engines. We plan to go 48V this time around.


We're located in Europe and I have no issues ordering stuff from the various Chinese platforms or Amazon.
Epever & Daly served us nicely on our previous system, I am not a big fan of expensive stuff from Victron or the like.


We will install 6 bifacial 450W solar panels (https://www.leroymerlin.it/prodotti/...-95285947.html)
&

(16x) 314Ah LiFePo4 cells from Gobelpower.


I like to hear what others with a similar setup have chosen successfully as components regarding:


*BMS
*Cell balancer
*Solar controller (One for each panel?)
*Inverter (48V to 220V)

*Shore side charger (110V & 220V)
*Battery to battery charger from starting battery to LiFePo4


IMPORTANT, WE WANT A RELIABLE LOW BUDGET 48VOLT SYSTEM.


We are 99% of the time at anchor and like to keep things simple, so I prefer not to have a huge amount of fiddling to do with different settings on each component.
Balance the cells initially, then set parameters once and have the system run reliable for the next two years until we might do another balancing.
So no real need for Bluetooth on components, a cable to s PC is fine. If the stuff has Bluetooth it's no problem though.


Of course we will add one of those simple instruments showing Amp, Voltage and SOC.
We usually switch charging sources off manually at 90% SOC.


Thanks everyone, looking forward to your suggestions and help this time around.

Cruzpro www.cruzpro.com makes a 60V version of their VAH60 www.cruzpro.com/vah60.html that might interest you. The 60V version is not listed on their website but they do have them in stock. Comes complete with a 150 amp current shunt for monitoring current and does keep track of charge remaining and has alarms, etc.


Regards,


Bert van den Berg
bvdb@cruzpro.com

[The Sun King]

The good news is that LFP batteries are cheaper than ever, even with the tariffs. Cabinet and wall batteries have a wide price range. Watch the rated service life. That cheap battery may have 4000 cycle cells. I'm seeing prices less than 2 grand to over 3 for a battery of 15-16kwh.

The batteries aboard Sun King are homebrew, but if I did it again, I would go with golf car batteries. They are sealed up. Cheaper ones are in plastic and if you want to spend much more you can get them in metal. I have both kinds of gc batteries in my farm vehicles and am pleased with both. I have paid 600-1200 for 5kwh gc batteries. I will never go back to lead!

I would avoid Daly BMS. They may have corrected this, but the ones I had did not balance cells unless charging on the high end. The result was me losing lights and propulsion in a twisty portion of a narrow, gator infested river at midnight, which I found to be annoying. Most of my batteries in the house and the boat now use JK BMS.

[s/v Jedi]

Originally Posted by Jdege

Do you?

I've been looking at the Genasun Boosting Solar Charge Controllers .

I've not played with one, yet, but they claim to be able to charge 48V batteries with any input voltage between 5-60V.

Do they not work? Or is there some disadvantage to boost controllers I want aware of?

I recommended those once years ago and they performed very well but this was a setup that didn’t allow for a series connection (rather small sailboat)

Whenever you can install multiple large panels edge to edge, pointing in the same direction and without shading from a boom overhead, you are far better off connecting in series. For both the house batteries and the solar arrays, getting the voltage up high is the path to efficiency.

[CaptainRivet]

Originally Posted by s/v Jedi

Whenever you can install multiple large panels edge to edge, pointing in the same direction and without shading from a boom overhead, you are far better off connecting in series. For both the house batteries and the solar arrays, getting the voltage up high is the path to efficiency.

That situation basically never exits in reality on a sailing vessel as your mast or boom will always shade a panel, maybe not for the 2 or 3h at noon in one location but the next location the tidal currents just moves your vessel so sun comes from bow and mast is shading partly min 1 panel doesn’t matter where onboard installed.
On a boat best solution is always one MPPT per one panel to harvest max you can get, especially with bifacials. No series no parallel connection. And 2nd find the shortest cable run and oversized the cable. And 3rd choose as big panel as you can fit.
Correct to get voltage high so choose your panels wisely and get the highest voltage panel that fits. When upgrading my 345W bifacial Longli to the 535W JaSolar bifacial, the Longli operating in 33-35V range while the JaSolar 40 till 43V range so with 55% more harvest I still have the same till slightly higher currents through the cables till the MPPT.
The issue with 48V to find single panels that have high enough voltage so either a voltage booster or panels in series, on most vessels I expect a better harvest with the booster. Same if you have very long cable runs.

[s/v Jedi]

Originally Posted by CaptainRivet

That situation basically never exits in reality on a sailing vessel as your mast or boom will always shade a panel, maybe not for the 2 or 3h at noon in one location but the next location the tidal currents just moves your vessel so sun comes from bow and mast is shading partly min 1 panel doesn’t matter where onboard installed.
On a boat best solution is always one MPPT per one panel to harvest max you can get, especially with bifacials. No series no parallel connection. And 2nd find the shortest cable run and oversized the cable. And 3rd choose as big panel as you can fit.
Correct to get voltage high so choose your panels wisely and get the highest voltage panel that fits. When upgrading my 345W bifacial Longli to the 535W JaSolar bifacial, the Longli operating in 33-35V range while the JaSolar 40 till 43V range so with 55% more harvest I still have the same till slightly higher currents through the cables till the MPPT.
The issue with 48V to find single panels that have high enough voltage so either a voltage booster or panels in series, on most vessels I expect a better harvest with the booster. Same if you have very long cable runs.

The OP has a catamaran that doesn’t have the boom over the panels.

Even I, as monohull don’t have the boom over my panels and that’s with two booms!

The mast is much less of a problem.

[CaptainRivet]

Originally Posted by s/v Jedi

The OP has a catamaran that doesn’t have the boom over the panels.

Even I, as monohull don’t have the boom over my panels and that’s with two booms!

The mast is much less of a problem.

But that situation that you get no shading does not exists in reality on a sailboat
Me2 have the panels edge to edge over the sugarsoops and davits with no booom but you still get shade from boom, mast, rig... when the sun comes from the bow or till 45 degrees both sides doesn’t matter how high you allways one panel is at least partially shadded that when they would in be in series I would take all 3 panels out. A simple side or backstay is enough to take all 3 out or at least reduce output significantly, absolute noGO. I tried it on mine, all in series, all in parallel and one per MPPT. The clear winner was one MPPT per panel by far and series connection nearly half the harvest was lost over course of 3 month.
Series connection on a sailing vessel is a noGo.
Best solution is one panel per one MPPT on a vessel, keep cable run short and oversize wire.
Solar panels costs nothing anymore, my new ones where 85Euro the piece, you just search for the best fitting biggest panel possible with the highest output, then order it. Transport on mine was more expensive then the panels itself and needed 4 weeks. Yes it is a hassle to organize and do that but its worth it as you cannot fix like a too low voltage afterwards. Its only 2 till 6 panels in average, so get the best panel and ignore the cost of it, the arch will be the cost driver.
Eg Franziska bought here really low voltage panels, I am sure you can find better ones with higher voltage, fixed panels are so cheap that the cost of the panel doesn't matter at all in relation to the arch/frame you need to build.

[s/v Jedi]

Originally Posted by CaptainRivet

But that situation that you get no shading does not exists in reality on a sailboat
Me2 have the panels edge to edge over the sugarsoops and davits with no booom but you still get shade from boom, mast, rig... when the sun comes from the bow or till 45 degrees both sides doesn’t matter how high you allways one panel is at least partially shadded that when they would in be in series I would take all 3 panels out. A simple side or backstay is enough to take all 3 out or at least reduce output significantly, absolute noGO. I tried it on mine, all in series, all in parallel and one per MPPT. The clear winner was one MPPT per panel by far and series connection nearly half the harvest was lost over course of 3 month.
Series connection on a sailing vessel is a noGo.
Best solution is one panel per one MPPT on a vessel, keep cable run short and oversize wire.
Solar panels costs nothing anymore, my new ones where 85Euro the piece, you just search for the best fitting biggest panel possible with the highest output, then order it. Transport on mine was more expensive then the panels itself and needed 4 weeks. Yes it is a hassle to organize and do that but its worth it as you cannot fix like a too low voltage afterwards. Its only 2 till 6 panels in average, so get the best panel and ignore the cost of it, the arch will be the cost driver.
Eg Franziska bought here really low voltage panels, I am sure you can find better ones with higher voltage, fixed panels are so cheap that the cost of the panel doesn't matter at all in relation to the arch/frame you need to build.

For you it is impossible, but I am not talking about you, I am talking about my boat which does not have any shading on its primary 2kW solar array and the OP who manages 3kW because it is a catamaran.

[CaptainRivet]

Originally Posted by s/v Jedi

For you it is impossible, but I am not talking about you, I am talking about my boat which does not have any shading on its primary 2kW solar array and the OP who manages 3kW because it is a catamaran.

Op has exactly the same situation as i do, catamaran and out in the stern over davits and sugarscoops. Edge to edge each panel. My cable runs are 5m with 4mm2 and 15A max. Per panel.
So there is shade, always when sun is from the bow and at least 30 degrees left and right from the bow. And my sidestays are very much front for a cat, can do 180 degrees with the main. If they are more rear its worse then 30 degrees when you get shade through them.
You have no shade when sun comes from rear quarters but because its a boat wind or tidal currents can change that fast. Just came from a location Alvor lagoon Portugal where one month tidal currents put your boat always for the 1st 3 weeks with the stern to sun and I couldn't use all the energy I got, the next month the tidal currents put the cat always the first 3 weeks with the bow into the sun and I had to be carefull with energy with nominal 2.5kw solar and run generator all 7 days to top up my 1088AH bank as there was a deficit daily even in september in summer. That with panels in series would have been a desaster , for mine or Franziska cat in that location.

Also for your boat, it is impossible when the sun comes from direction bow you have no shading due to mast or a rigging wire doesn't matter where your panels are located on the boat.

[s/v Jedi]

Originally Posted by CaptainRivet

Op has exactly the same situation as i do, catamaran and out in the stern over davits and sugarscoops. Edge to edge each panel. My cable runs are 5m with 4mm2 and 15A max. Per panel.
So there is shade, always when sun is from the bow and at least 30 degrees left and right from the bow. And my sidestays are very much front for a cat, can do 180 degrees with the main. If they are more rear its worse then 30 degrees when you get shade through them.
You have no shade when sun comes from rear quarters but because its a boat wind or tidal currents can change that fast. Just came from a location Alvor lagoon Portugal where one month tidal currents put your boat always for the 1st 3 weeks with the stern to sun and I couldn't use all the energy I got, the next month the tidal currents put the cat always the first 3 weeks with the bow into the sun and I had to be carefull with energy with nominal 2.5kw solar and run generator all 7 days to top up my 1088AH bank as there was a deficit daily even in september in summer. That with panels in series would have been a desaster , for mine or Franziska cat in that location.

Also for your boat, it is impossible when the sun comes from direction bow you have no shading due to mast or a rigging wire doesn't matter where your panels are located on the boat.

Comparing profile info you have a very different boat than the OP and me.

[CaptainRivet]

Originally Posted by s/v Jedi

Comparing profile info you have a very different boat than the OP and me.

Every sailboat has at least one mast and rig for it and when sun comes from bow that mast and rigging does shade on the panels doesn't matter where they are mounted, at least one gets a wire shadow. Thats physics and your boat is not an exception to that as well as Franziskas cat and mine are not.
What cat does she have now, old was a woods 35.

All catamarans if mounted at the stern is all the same doesn't matter if Lagoon or a performance cat.
And if not shaded by the boom means either
1) overhang/extended from the end of the roof out to the stern.
2) or panels are mounted on a solar arch above the davits/dingy and sugarscoops which is lower so you get some shade from the pilot house too when sun from bow but also less windage.
Thats how you can fit 3-8 panels side by side on a cat, nowhere else so the model doesn't matter its one or the other.

[Franziska]

So we are getting close to order our stuff.

Need to clarify few items before and hope even @Jedi chimes in, despite the shock he got from my post #18. It was not my intention to offend you.

IMPORTANT:

WE ARE GOING 24V, NOT 48V.
WE ARE STILL ON A BUDGET (!!!)
WE PREFER TO KEEP THINGS REASONABLY SIMPLE. LESS SETTINGS TO FIDDLE WITH IS BETTER FOR US.


BOAT & USE DETAILS
Regarding the boat, she is a fast Cruiser Racer Catamaran.


-No washing machine
-No electric oven (for now)
-No big aircon (perhaps a small unit for the aft cabin one day)
+Watermaker
+Hot water from solar electric
+Sundry kitchen equipment
+Induction stove

We live full time, over the full year, onboard, currently in the Mediterranean, almost always on anchor, rarely use the engines.
Main reason for big solar array is that we are also in the winter season onboard.

The panels will be mounted behind the cabin at chest height. Less windage and easier to clean. Provides added safety barrier for the cockpit.
No boom directly over it, but of course, pending on boat orientation some shading from mast and boom might happen when the sun comes from a fwd. angle.
The support arch doubles as dinghy hoist.
As described earlier, the two outer panels will be folded in under sail, at anchor all 6 panels will be side by side.

Yesterday we did order the six bifacial 450w panels (Specification post #9).
We also ordered (16x) LiFePo4 cells of good quality from Gobel Powers Polish Warehouse.
(https://www.gobelpower.com/european-...eads_p228.html)



QUESTION 1-SOLAR CONTROLLER
@Jedi wrote:
„...The Vmp is 33V. You must connect panels in series. These panels are built to be connected in series and you need the voltage for efficiency. But when you go for 24V batteries then two panels in series will be just fine. This works out well for your setup: the two center panels are a pair, then the two next to those and finally the two you flip over on top…“

So I get (3x) Victron 150/50, one for each pair. CORRECT?


QUESTION 2-BMS
On our old boat we switched the solar off manually when the batteries where at 90% SOC.
@CaptainRivet wrote in a post that he has used an Electrodacus BMS to disconnect the charge sources automatically when SOC is about 90%. Honestly I find the Electrodacus a bit daunting.

Is there a simple, and not expensive (!!!) to achieve this with a simpler BMS?
Which one shall we get if we want that functionality but not 1000‘s of extra settings?

For our 16 cell 24V LiFePo4 battery pack we only need one BMS, correct?

If we want a simple one, is this one: JK 8S-16S 200A BMS LiFePO4 JK PB2A16S20P
https://powercells.de/jk-8s-16s-200a...ml?language=de
a good choice?


QUESTION 3-B2B & SHORESIDE CHARGING & ALTERNATORS
As we hardly ever go into ports or marinas we keep our 40A 12V shore charger and do not replace it with a bigger charger for now. In a worse case scenario we can even run that with our little Honda EU22i genset.

The 40A 12V charger charges the 12V 100A starter battery and we plan to use a B2B charger then to spill enery over to the Lithium.

We hardly ever run the engines and the large solar should suffice under almost any situation.
Due to cost we will fix only simple standart automotive style 12V alternators with about 100A and nothing fancy for now.
Same as above, 12V starter battery gets charged and the B2B charger will then spill enery over to the Lithium.

I tried to find a reasonably priced B2B charger to go in between 12V starter battery and the 24V LiFePo4.

Out of these B2B chargers, which one do I buy?
https://www.svb24.com/en/category/battery-to-battery-chargers-for-boats?attributes=3550___Battery%20type___Lithium%2 0(LifePO4)%7C47___Output%20voltage___24%7C129___In put%20voltage___9-16&sort=relevance~desc


Should I bite the bullet and buy the big Sterling?
https://www.svb24.com/en/sterling-bb...12v-120-a.html
It seems its the only one which can act in reverse and to also top the starter battery up if its not fully charged.
As we hardly ever run the engines and it has no separate charge source that seems good.
Also if we one day get bigger alternators it could perhaps spill more over?
We also install a manual switch that we can choose which one of the starter batteries it uses.


QUESTION 4-INVERTER
In post #14 @Jedi suggests 2x the Victron Multiplus 24/3000 (https://www.victronenergy.com/upload...VA-5kVA-EN.pdf)
These are charger/inverters.

Due to rarely using other charge sources the solar I am wondering if we can not use 2x Victron Phoenix Energy 3000VA 24V instead. They are just inverters and can also be used in parallel.
https://www.victronenergy.com/upload...-5000VA-EN.pdf
That would save us a couple of hundred €.

Good choice?



Appreciate the input from all of you!!!

[nfbr]

Copy RD Franzi, its much cheaper and betterer


Good luck with a big job

[Franziska]

Originally Posted by nfbr

Copy RD Franzi, its much cheaper and betterer


Good luck with a big job

Thank you very much for your kind help today.
Feels good to have the system defined now.


Also thanks to all others contributing to this thread.
In the end we have now ordered all vital components from Victron and built 48V.


Thread purpose fulfilled.

[CaptainRivet]

Originally Posted by Franziska

Thank you very much for your kind help today.
Feels good to have the system defined now.


Also thanks to all others contributing to this thread.
In the end we have now ordered all vital components from Victron and built 48V.


Thread purpose fulfilled.

So what BMS will you use?
How to solve the solar panel issue? 33V with 2 in parallel gives you 66V, too tight for 48V which goes 58.4V.
How does the 12V alternator charge the 48V bank?

[nfbr]

Originally Posted by CaptainRivet

So what BMS will you use?
How to solve the solar panel issue? 33V with 2 in parallel gives you 66V, too tight for 48V which goes 58.4V.
How does the 12V alternator charge the 48V bank?

33 is 66 in series.
As per Victron Smartsolar MPPT, the spec is +5V to start and +1V to operate.

Ideal adsorb is 56V. Float 53.5ish

That's 52+5 for the AM = 57, well under 66
Even at 56 + 5 at end adsorb it's still 61, well under 66.
And thats to start. Operating is 56+1 = 57

Operating it only need 57V to hit full adsorb, so the panels would have to be super hot to drop from 66 to 57.

6 panels with 3 of Smartsolar 100/20 has 48V support and will handle 17.3A rated output.