diy solar

diy solar

"New" Sailboat Build

willo

Solar Enthusiast
Joined
Apr 8, 2020
Messages
450
The boat? 1973 Ericson 46. It. Is. Yuge.

Currently, it has an older Xantrex 2000w inverter/charger. Sadly, It doesn't support lithium charging profiles.

Here's what I'm leaning toward:
Multiplus 12/3000 (110v) Inverter Charger. (May add a 230v auto transformer on the input later on)
I have a 3k on my camper and love it.

I'll drop in a AGM on the engine starter side and use it as a buffer to provide a high amp charger source when the engine is up. I'm looking into a 175A alternator kit.

For solar, I'm hoping to get 3-4 350-400w panels on my Bimini. I have a pretty deep cockpit and will extend the rear pair over the stern a bit. I will probably run a SCC per panel or two to keep the watts down. Victron MPPTs all the way there.

I had an interesting conversation with someone who has panels mounted upside down so they can flip out - he reported 85% output from reflected light! He doesn't even bother flipping them out and just leaves them where they are. It could be an interesting way to add capacity on limited surface areas like the monohulls.

Battery wise, I'm just trying to decide how much $$ to throw at it. I'm torn between 16 and 32 cells, probably on the 280ah side. I guess I'll spreadsheet it up again but last time I did the difference between $/Ah was minimal for say 100-200-280 cells.

I've been using SMBS0 on my camper. I may continue with it, but it does require higher end SCCs that support remote control. I may opt for something different. One issue I'm pondering is if I can build out a pair of packs on each side of the boat.. I figure that would take a pair of BMS and I *know* that Dacian doesn't want to support that on the SBMS0.

Like my camper, I'll network it all to a raspberry pi running the venus image.

Edit: I may go ahead and add a couple of DC-DC converters between the starter and the lithium bank. More money but better charge profiles and can be bypassed in a pinch at 12v.
 
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That seems like a great option for a lifeline mounted panel or two...
 
The 12v vs 24v has been a thing in my mind. I actually run 24v in my camper. I chose it there to deal with 1200w of solar with a single SCC.

Mainly? Simplicity. It's one less piece of gear to worry about. - no 24v-12v converter needed. (OK, I'll be fair here. I haven't assessed if a 24v native system will work on the boats systems. But I know the engine is setup for 12v operation.)
The cost of staying 12v? BIG FAT CABLES - which already exist.

As she sits.... In case of equipment failure:
I can trivially start the engine off the house bank.
I can charge directly from the alt/starter battery if I want. I will probably spend a little on DC-DC charge controllers as insurance on the 2-4k I'm looking at spending on batteries.

However,
I suppose I can look at how hard it would be to convert my Beta to support 24v. I'm already planning to replace all the lighting with LEDs that would support 24v. Of course, there are various other items - toilet pumps, gulpers, water pump, bilge pumps, etc that I need to verify. The downfall there is that I'll have to do all of it at once, where just running 12v would let me take my time (I can use the old inverter for a while, for example)
 
The two biggest consumers of power on the boat will certainly be the A/C and the fridge.
The top loading fridge has an Adler Barbour DC power system. It's at least 15 years old, but should be reasonably efficient.

I've ordered a new marine A/C system - and this is exciting for the solar/battery system...
The Velair units are a bit more expensive than the usual systems, but they have:
  • Soft start by design
  • Electronic expansion valve to adjust flow rate (less cycling)
  • Variable fan speed (less cycling)
  • Brushless compressors
  • Reverse cycle (heat too)
  • Varied cooling from 4000-16000btu
There's a (mostly boring) video where this guy is running TWO of these things off of a honda 2200i Generator.
He does point out that he had the boat cooled before starting up, but it's a great demo of the soft start feature.


Great info from the CE label in the video:
Max input power 1050W. That's insane to me for 16,000 btu!
Max current 9.6A
OK, that doesn't account for the raw water pump power consumption.

I found some data on Cruisersforum that's interesting:
Draw varies from 2a-9a AC, with a water pump on that particular boat they pull 33a-100a DC. (gonna assume 12v system there)

Anyway, it's a step forward!

Next up, inverters and solar controllers...
 
I've been using SMBS0 on my camper. I may continue with it, but it does require higher end SCCs that support remote control. I may opt for something different. One issue I'm pondering is if I can build out a pair of packs on each side of the boat.. I figure that would take a pair of BMS and I *know* that Dacian doesn't want to support that on the SBMS0.
I do not know the functionality of the SMBS0, but Installation on a boat has some requirements that are different from a land installation:
  • it could be unsafe if the BMS shuts down the battery in certain situation (no VHF, no lights, no autopilot..) so the BMS must give sufficient warning at the chart table before cutting the loads (a few minutes). Best is to have a first warning level that stops the chargers (or disconnects the non-critical loads), then a critical alarm level that isolates the battery if the situation gets worse (of course with advanced warning)
Other considerations that may be important:
  • how do you know the BMS, its configuration and the wiring of the equipment it controls are OK and it will all work as planned the day you need it? Many things can go wrong, from human error to poor connection, and you want to check that regularly. Without a "fault simulation" feature (like smoke detectors and other safety equipment have) it is very hard to know.
  • when the boat is left unattended for an extended period and power consumption is low, you do not want your solar to float the battery full all the time. The BMS needs to control the regulators so that the SOC cycles between 30% and 50%
  • with a large inverter it is a good idea to pre-charge the input capacitors before closing the load relay.
  • it looks like you will be using Victron equipment and you may want the BMS to remote control each of them (either by wires or CANbus)
  • not sure if you are planning on an alternator regulator, but the Wakespeed WS500 can be remotely controlled by a BMS (wire or CANbus)
  • when you leave the boat unattended at anchor and powered you may want to monitor your battery and BMS activity remotely from home (Cloud)
Maybe SBMS0 takes care of all that, and that's great you are on a good path. Otherwise you may want to look at the specifications of TAO BMS that has been designed by a sailor for sailors.
 
One point here... What are you basing your soc level for storage on? Those are zero load numbers in my experience. Think unplugged storage.

I have found that my systems get exercise even when away. For example on the boat, I will happily run a/c on low when away. On my camper I run my dometic dc cooler freezer constantly. I will certainly run a/c on low to reduce humidity. Powering security systems will be minor but also another load. There's a good argument for a storage mode the drops battery down to 50% before starting charge...
 
For unplugged storage, the best is to charge to 50%, then disconnect all wires (including the BMS) from the battery, and keep the battery in a cool place.

Like in your case, my system is also always on even if not on board for a long time (going overseas). Depending on location and length of time it powers the fridge, freezer, dehumidifier, bilge pumps, anchor light, AIS.... For that I set the Charge Cycle Management to stop charging at 80%SOC, and restart charging at 30%SOC. It does a partial charge to 80% every 2 to 4 days, with a full charge every 30 days. If battery voltage is too low due to lack of sun, the BMS cuts the dehumidifier and other non-critical loads (keep the freezer on as long as possible!)
And the good thing is that I can remotely access live measures, historical measures and history of events recorded by the BMS (start/stop charge, full charge, balance....): My battery cloud dashboard
 
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Are you planning for long trips ? ocean crossing ? coastal sailing ? electrical cooking, International sailing ? ( 120/220 V 50/60Hz )
The design for your installation and cost are depending on the answer .
But for sure you need more than one panel Charger controller on a sail boat due partial shadowing , changing solar angle and son
 
Some decisions have been made!

I've decided that I want a bit more than 3kw on the boat, I'm aiming for a 5000VA inverter this time.
It'll be either a quattro or a multiplus, depending on what kind of deal I can find.
This means I'm opting for 24v to keep amperage on the battery wiring run remotely sane.

I'm going to slowly convert all DC accessories to 24v where possible. I'll work my way through auditing them. In the meantime, I have a spare victron DC-DC converter I can chuck in there. It's not my favorite as it is the 40A design but I already own it.

After considering options, the BMS shall be SBMS0 - and yes it does have some test options. Specifically it has some opto-isolated outputs that can be set for various level triggers. I can make one of these be an alarm trigger.

I have also decided to eliminate propane from my boat. (The old system is dangerous, really)
This means all electric cooking. (One more reason for going to 5kva on the inverter.)
I'd just picked up a new propane grill but it's small enough I think I can just stow it and maybe pull it out for beach excursions.

Going for:
Electric Weber Q 1400 or 2400, I need to think about sizing. (and where to add a power outlet in the cockpit for it.)
Induction cook top - that'll get installed into some form of gimbal.
Some form of electric oven - still shopping.

As mentioned before, A/C is going to be a Velair 16,000BTU that's perfect for inverter/solar operation - no soft start needed, brushless compressor, variable speed fan and variable expansion valve so it can cycle down in BTU and reduce those expensive cycles.
 
Sweet, quattro 5000 is happening. Between that and the soft start variable air conditioner,
this should minimize load balancing games on the boat.
 
On the grill front (Important to me!) I'm going with the Weber Q1400. Same electric bits but heats faster since it's smaller. I think it'll be more efficient overall.

Batteries are still waiting unloading... hopefully they ship in the US next week.

On the BMS side, I'm making progress. I'm going with something I can integrate via canbus: OrionBMS, RECBMS, EMUS BMS have all caught my eye. Orion answered the phone when I called and there's even a local dealer in CO that I could lean on if I need something.
There is an effort to add integration like this to the SBMS0 but it's not mature enough IMO for me to install in my boat and trust it when I'm away.
 
Sweet. I got tracking numbers today for fedex. Cells should arrive in time for my boat working session later this month!
 
I've got an OrionBMS Jr on the way, decided to go with a Cerbo GX for the canbus integration AND so I can add tank monitoring. Of course I still had to get another friggin usb-mk3 so I can update firmware and easily run ve.configure.
 
Friday, I drove to SanTan Solar in Georgia. There I picked up three 530w solar panels! These things are epic.
I am installing a dedicated 100/20 controller per panel. This should optimize charging for the usual sailboat issues.
Each of them will be linked to my cerbo gx via ve.direct (aka rs-232 serial)

My 24 304Ah cells were at the marina when I arrived. I have nearly 24kwh of battery. Booyah.
After playing around with layouts, I've settled on a pack design to fit in my existing battery compartment under a setee.

I ordered $250 in Copper 101 bar stock from McMaster Carr to make custom bars. I paid for next day shipping so of course one box got lost. Enough showed up that I can get started at least.

Last weekend I picked up my quattro 5k inverter. Dang it's huge compared to the 3k.

So yeah...
Battery cells - arrived, hauled up the damn ladder (boat is on the hard)
Bus bar material, mostly arrived.
Inverter/Charger - picked up.
SCCs/VE.direct cables - arriving later this week.
Panels - picked up.
BMS - Brought it with me.
Contactor - in hand.

I'm down to getting some 10 gauge for the solar panel runs and then making up the big wiring. I've got plenty to work with so probably just adding new ends. And of course I keep thinking I'm demolishing my current nav station...
 
Quattro is mounted and has A/C In/Out - easy since it was already wired for an inverter. It's talking happily over ve.can with my cerbo GX.
I'm just about ready to start building out the battery pack. - I have copper 101 bars to cut and drill, and then I need to get mounting sorted.
Today I've got a 24/12 converter coming (I forgot my smaller one at home) so I went with a new 70A that will run everything on the boat except the windlass end diesel starter.
For big loads I'm keeping a standard 12v system around. Probably tossing an AGM in there and getting rid of all the FLA stuff.
Later I'll add a 24/12 charger to keep it topped up. For now on the hard I'm just using the aux charger that's built into the quattro.
 
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