what size of solar power do you have on your Trawler

So grateful for all the input here. Learning from members about the productivity from real working systems instead of theory on what should work is just the data needed for those of us still in the planning stage.

Wild Blue said:

Texas:

Yes. Here's the detailed answer:

The Fisher-Panda has an "automatic adapter RE0704" accessory that provides a contact pair that when closed starts the generator, including a start sequence and warm up. When the contacts are opened the generator stops, after a short cool down.

The battery bank state of charge (SOC) is monitored by a Victron Cerbo-GX. This is a little computer box which connects to the battery management controllers (BMS) to get the SOC. We set start gen to 50% SOC and stop gen to 80% SOC. The Cerbo GX closeds and opens the contacts to start and stop the generator.

Since it's a LiFo battery bank, the generator runs totally loaded at 27.8v 200a. We have an 1100+ amp hour bank, so every hour the generator charges approximately 20%. It takes roughly 90 minutes to get from 50% to 80% SOC.

Alex

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I recently finished up a similar auto-start. Like Alex's system, mine reads the SOC from the LFP battery BMS, and starts/stops the generator accordingly. The generator has a warm up and cool down period, with automatic load connect/disconnect.


I can set it to any value but currently the gen starts when the SOC drops below 40%, and stops when it reaches 90%. With Inverter/chargers plus stand alone chargers operating, it takes about 2 hrs to go from 40% to 90%. Hot water also gets heated during that time, and together pretty well fully loads a 25kw generator.


What's different from Alex's system is that mine uses the existing AC generator, inverter/chargers, and shore chargers, rather than a dedicated DC generator. Both approaches have their pluses and minuses.



I've also been adding some safety checks to guard against a generator that gets started, but never stopped. Right now there are two checks. The first watches for a minimum load on the generator, and shuts it off if the load drops below the threshold for 5 minutes. That will catch chargers that shut down for some reason, tripped breakers, or other things that keep the chargers from actually drawing power. The second check is just a max runtime limit. That's kind of the catch-all for a generator that gets started, but where the batteries never reach the SOC point where it would get shut off.

Peter:

As always great ideas.

It is worrisome to hear the generator, as quiet as it is, start in the middle of the night. Even difficult to get back to sleep for fear of it not shutting down.

More worrisome when away from the boat with generator auto start enabled. Hope to install the Maretron wifi device and use Starlink to alert when auto start and auto stop occur.

Have you implemented such an alert?

Alex

Wild Blue said:

Peter:

As always great ideas.

It is worrisome to hear the generator, as quiet as it is, start in the middle of the night. Even difficult to get back to sleep for fear of it not shutting down.

More worrisome when away from the boat with generator auto start enabled. Hope to install the Maretron wifi device and use Starlink to alert when auto start and auto stop occur.

Have you implemented such an alert?

Alex

Click to expand...

I don't have mine sending me email alerts yet, but that's on the list of things to do....

healhustler said:

So grateful for all the input here. Learning from members about the productivity from real working systems instead of theory on what should work is just the data needed for those of us still in the planning stage.

Click to expand...

For my side on our Ex-Terranova Explorer 85 I installed 18X 335Watt solar panel so total 6030Watt with 3 Mastervolt MPPT 60A each.

We Have almost every day a noon each controller a 60A so total 180A at 27V total 4860 Watt so 80% from the max theory, it look like very nice but I will I was limited by controller..

Anyway on you next boat I'm trying to for 16X 400Watt and not be limited by controller.

Generator just scared the crap out of me starting up on it's own.... I guess the batteries are down to 40%...

Solar System

We have (3) 100 watt Allpower flexible solar panels fastened mounted on top of the flybridge bimini via zipper/velco system. They are wired in series to a Victron 100/30 mppt controller to charge the (2) 225 ah fla 6 volt batteries. The system is adequate (600-800 wh/day) run the 3 cu ft refrigerator, water pump, vacuflush pump and lights (all led). There is no generator and no shore power available. The system is a little hard on the batteries toward the end of the season when several days of inclement weather so plan on adding more panels somewhere.

healhustler said:

So grateful for all the input here. Learning from members about the productivity from real working systems instead of theory on what should work is just the data needed for those of us still in the planning stage.

Click to expand...

A very accurate appriximation is to triple your solar panel wattage to get the total day's W-Hr production. So if you use 600 W-hrs in a day, you will need 200W of panels. Use a battery monitor to measure your W-hr consumption and that will determine your panel size(s).

435 watts of panels. Blues Sky solar Burst MPPT controller. 10 T-105’s cabled at 12 VDC.

We are primarily a 12 VDC boat, with fridge and freezer units running at 12 VDC. As such the inverter is switched off unless we are traveling or the inverter is needed for microwave, coffee grinder or other AC loads I.e. we like the AC sconce lights for reading at night. We have a propane range.

The normal usage is about 250 ah/day. We seldom drop below 85% SOC overnight. On a sunny day, the solar will “just” bring the batteries to fully recharge by 5:00 pm, but it doesn’t go out of threshold charge, i.e. probably needs additional charging. That is without using the Genny. The T-105’s are long-in-the-tooth at 8 years of age.

The general “rule-of-thumb” (assuming you have opposable thumbs) is to put on all the solar panels you can possibly put up on the deck/roof. Preferably ridged panels.

Jim