Solar, generator, or nothing?

[BugzyCan]

I have 26' Macgregor that I am planning a 4 week trip on this Summer. Most likely solo unless I can convince someone to come with me.

It currently has a single battery, but I will add a deep cycle battery, perhaps a red top AGM (open to suggestions on that), but I will need some way to charge the set too.

I could add a solar panel, which would involve various updates to boat, such as a rack on back to mount it on, or perhaps I could mount it on top of sliding galley roof if I can find one to fit. I rarely step there. Concern is, if I get a number of rainy/cloudy days, it may not charge enough?

Another option is to buy a small Honda generator, which I would need to fit someplace in cabin, or perhaps it could go somewhere else on deck if strapped down and covered (?), then it needs gas, so would need to bring those, and keep filling as needed, but for a 4 week trip, maybe that would not occur too often. My understanding is that a 3000 watt generator will run around 8 hours on its internal tank of gas, and it should only take an hour or two (?) to charge batteries.

A third option is to not get either of those, and to fire up the motor occasionally to charge up the batteries. I may end up running the motor anyways if there is no wind, or too much wind and for docking etc.

Should I bother with anything for this?

I will be mostly off the grid for this trip, around the islands north of Vancouver BC (Desolation Sound etc.).

[sailorboy1]

Fire up the engine! You probably at most for av1 week trip need 5-gal fuel of energy

After the trip you will have a better long term idea of what be best for you.

[Topspin]

For a trailer boat it is always a good idea to at least fit a small solar panel to keep the batteries topped up when on the trailer. I have two batteries (house and E-Winch for the lift keel) and this concept works pretty well for me.

Maybe a small honda would be a good idea for cruising unless your outboard engine has an alternator installed.



-Richard

[a64pilot]

Your only gone for a month, borrow a Honda if you can or buy one.
Solar is wonderful, but your only gone a month and Solar can cost more than you may think.
Actually in my opinion Solar complements a generator, or the other way around, whichever you prefer.
It takes on average six hours of good charging to fully charge a battery, Generators are great for making tons of power in a short time, Solar is outstanding for making small amounts all day long.
So generator alone and you had to run the thing all day long, Solar alone and you stand a very real chance of not fully charging, so run the generator in the morning before Solar is making power for 30 min or so and slam a bunch of power in fast, then shut down and let Solar polish it off.

But your only gone a month, and a Honda you can likely resell easily if you chose not to keep it, in that month most likely you will only be charging your battery up to about 85% full. That’s when the hours to fully recharge kicks in, but you can get to 85% in an hour or so assuming you didn’t go below about 50%

To get from 75% charged to about 90% takes me an hour with my charger, but to go from 90% to 100% pretty much takes the rest of the day, even with the shore power charger.

[DefinitelyMe]

What are your loads? Do you have a fridge or any other high-draw stuff or are you just trying to run some lights and charge a laptop?

I don't think it's worth investing much (or maybe any) money for the sake of four weeks. Your batteries can take a hit for four weeks. On the other hand, if you're only looking at running minor loads then it might be worth buying an inexpensive 50W solar panel and a very cheap PWM controller from amazon or whatever. Don't mount it permanently unless you really like it; just stick it somewhere sunny when you're anchored. It it's not cutting it or it's too cloudy that day then you could always run the engine for an hour in the morning to get the bulk of the charge in.

[Lost Horizons]

I had an M26C and another trailerable boat, and the only source of electricity was an outboard alternator on each of them, which I hardly used at all - a 3 gallon tank lasted full season. The electrical consumption was mainly navigation lights and cabin lights; my trips were typically 2 weeks off the grid. If you need more energy, get an extra battery. I suppose you can start your outboard by pulling a cord, or is it a motor-sailing model with a large motor? If it is, you will probably need to have a separate battery for the starter.

[ramblinrod]

Originally Posted by BugzyCan

I have 26' Macgregor that I am planning a 4 week trip on this Summer. Most likely solo unless I can convince someone to come with me.

It currently has a single battery, but I will add a deep cycle battery, perhaps a red top AGM (open to suggestions on that), but I will need some way to charge the set too.

I could add a solar panel, which would involve various updates to boat, such as a rack on back to mount it on, or perhaps I could mount it on top of sliding galley roof if I can find one to fit. I rarely step there. Concern is, if I get a number of rainy/cloudy days, it may not charge enough?

Another option is to buy a small Honda generator, which I would need to fit someplace in cabin, or perhaps it could go somewhere else on deck if strapped down and covered (?), then it needs gas, so would need to bring those, and keep filling as needed, but for a 4 week trip, maybe that would not occur too often. My understanding is that a 3000 watt generator will run around 8 hours on its internal tank of gas, and it should only take an hour or two (?) to charge batteries.

A third option is to not get either of those, and to fire up the motor occasionally to charge up the batteries. I may end up running the motor anyways if there is no wind, or too much wind and for docking etc.

Should I bother with anything for this?

I will be mostly off the grid for this trip, around the islands north of Vancouver BC (Desolation Sound etc.).

Hi Bugsy,

We just chartered a day sail north of Victoria in September. Beautiful.

RE: Electrical System

To make it science rather than guessing, you need tie some numbers to it.

The first thing to do is perform an energy consumption calc.

For each 12 Vdc load on the boat:
1. Find the power consumption in Watts.
2. Divide this by 12 Vdc to determine Amps.
3. Multiply this times hours / day it will be running.

This will give you the Amp-hours / day of consumption for each device.

4. Now add them all up.

This gives the Amp-hours / day consumption for the boat.

So I'm just going to WAG so we have some numbers to play with.

Assuming no fridge, lets guess 20 A-hrs / day for everything. Don't just use this number, do the math. It will really depend on what electrics and electronics the boat is equipped with.

Next you have to determine how many days you will go between overnight marina visits, where you can recharge with shore power.

It could be anything, but lets guess 5 days max. (With no refrigeration, this is about how long your ice blocks will last in really good coolers, not that ice is essential but cold beverages are very civilized.)

So now, if you want to go 5 days without any source of charging between marina visits on shore power, you would consume 100 A-hrs.

You will want a max depth of discharge of 50% (for FLA batteries), so you will need 200 A-hrs of house bank capacity. 2 x Grp 27 deep cycle batteries would work well. Don't bother with expensive batteries. If you only do a 4 week trip once per year, and you never draw then down more than 50%, and you always return them to 100% every few days, they will last a long, long, time. If you do make a mistake, and run them right down a few times or leave them discharged in the off-season and totally kill them, well, you don't want to do this to expensive batteries.

Do you have a 30A AC shore power system?

If so, a 20 A, 2 bank marine charger would be fine. (~C$200)

If not, to add a proper 30A shore power system is ~$C500 plus installation.

An alternative to installing a shore power system and charger would be to add a solar charging system.

For 20 Amp-hour daily consumption, you would be well served with about 200W of panels. This would keep you topped up, even if you only had one sunny day in every two.

2 x 100W rigid panels with 20 A charge controller, fuses and cables would start around C$275 + installation. (Cheap semi-flex panels are at least double, and for the good ones, 4-8 times as much as cheap rigid.)

I don't really recommend portable gas generators on boats, though some people do it. (Too many risks of spilled fuel, CO poisoning, wiring issues, securing, space consumption, safe fuel storage, etc.)

If your outboard has a built in 10 A charger, it would take about 4 hours of mid throttle running per day, to replenish 20 A-hr consumption, until you could fully charge up with a shore power charger.

Hope this helps.

[Pizzazz]

I suggest two sources for redundancy. A small solar panel 50-100W, could be one of those foldable panels for emergency and backup. Alternator as the main charging source. Two golf cart batteries. You are all set.

[MJH]

Originally Posted by BugzyCan

I have 26' Macgregor that I am planning a 4 week trip on this Summer. Most likely solo unless I can convince someone to come with me.

It currently has a single battery, but I will add a deep cycle battery, perhaps a red top AGM (open to suggestions on that), but I will need some way to charge the set too.

I could add a solar panel, which would involve various updates to boat, such as a rack on back to mount it on, or perhaps I could mount it on top of sliding galley roof if I can find one to fit. I rarely step there. Concern is, if I get a number of rainy/cloudy days, it may not charge enough?

Another option is to buy a small Honda generator, which I would need to fit someplace in cabin, or perhaps it could go somewhere else on deck if strapped down and covered (?), then it needs gas, so would need to bring those, and keep filling as needed, but for a 4 week trip, maybe that would not occur too often. My understanding is that a 3000 watt generator will run around 8 hours on its internal tank of gas, and it should only take an hour or two (?) to charge batteries.

A third option is to not get either of those, and to fire up the motor occasionally to charge up the batteries. I may end up running the motor anyways if there is no wind, or too much wind and for docking etc.

Should I bother with anything for this?

I will be mostly off the grid for this trip, around the islands north of Vancouver BC (Desolation Sound etc.).

I sailed BC for 10 years with just my start and house battery on a San Juan 28. That's all you need with reasonable electronics.

_/) MJH

[henryv]

If you are spending four weeks on the boat you probably need some sort of refrigeration. A built in fridge or portable electric cooler will be your biggest power draw.
If your outboard is a 9.9 hp unit you will see only 6 amps when it is running above idle. Since you have a sailboat I would not expect to see many hours of engine running.
Your need for generation would be reduced and the health of your batteries will benefit from the addition of solar. You should try to fit 150 watts which you can buy at pretty reasonable prices on Amazon or Ebay.
If your area is likely to experience multiple cloudy days a backup portable generator will be nice to have but solar will still produce some power unless cloud cover is particularly heavy.

[hamburking]

You never mentioned what you need power for?

If you just have LED lights and some electronics, then you don't need anything. I had a C&C25 with 1 battery (and an outboard, no charging). I could go a full week using the electronics (including autohelm ALL day). All LED lights below. And my one battery would go a full week of cruising with hardly a dent in the SOC. I could charge at the dock only...the best thing I had was a really long extension cord.

The only reason you may need power is if you have refrigeration. And you have to ask yourself, is it worth buying a generator, gas, all that noise and pullution...just to have a cold cola? You can buy A LOT of ice for far less money. Your money and effort would be better spent on more insulation in your ice box. I found if I loaded up with 4 blocks of ice, my ice box would stay cold almost a week...during the heat of summer.

The other item that might use power is a big flat TV. In which case...use a tablet instead. Need to charge your phone...get a power bank...cheap, easy, common.

A generator would be a huge thing to try to stow on a M26...and even more awful if it were running. IMHO, your effort would be better spent on getting a good dinghy...but thats a whole nother thread.

Handheld GPS, handheld VHF, portable DVD player, a few good flashlights....I've done it, and it was great. KISS.

Enjoy being on a boat. Don't try to make it like a house on land.

[alansmith]

Not much wind in that area during summer. So probably good sun potential. You can buy a pwm controller dirt cheap. 50 watt-100 watt solar and you are good to go.

Also, I might add several other things that could help. I have an Engle 12 volt. But I sail the Sea of Cortez and there is nowhere to pick up shore power or ice for long periods of time. Many sailors go without electric refridges. But the old boxes that you put ice and beer in have changed dramatically over the last decade. Have you heard of Yeti? No! Not Bigfoot, but the camping refridges that you store your luncheon meats, cheese, yogurt, and mayonnaise in. They are very expensive but worth it. Well Yetis got competition these days. You can buy different sizes. You, honestly keep things cold for 5-10 days depending.

There are so many ways to do this. Dry ice in one cooler will keep you up to 10 days. Have smaller cooler for cold things... not frozen. Also the water is very cold where you sail. You can take advantage of that. I use my Engel as my freezer and my Yeti-like as my refridge. I have two one liter bottles with water. I keep one in the Yeti-like frozen and ready to swap with the thawed one in the Yeti-like.

It might help you to YouTube some fellas who are trailer sailors. See how they do their setups. You can actually hang your solar panels on your life lines with some very easy mods to the panels. Enjoy the learning curve. There are some amazing technologies available. Have fun.

[Apollo366]

I had a McG 21 Swing Keel for several years, So Cal & Sea of Cortez, regular car battery & very cheap small solar panel, worked fine for 1-2 week cruises. If i'd had an OB with a charger built in it would make even long cruises.

Learn to like KISS, it makes the sailing/cruising so much better & easier.

Cold beer is always available at water side pubs & u can hang the 6 pack over the side as needed ( works best with darker beers).

Enjoy, have fun!

Capt. Wayne

[LoudMusic]

I'm a big proponent of putting as much solar as your vessel will comfortably support, and as much lithium as you can afford, and then run the main engine to cover the rest.

[ramblinrod]

Originally Posted by LoudMusic

I'm a big proponent of putting as much solar as your vessel will comfortably support, and as much lithium as you can afford, and then run the main engine to cover the rest.

LiFePO4 makes little sense for this application. (Small bank so weight is no issue. Used only 4 weeks, so PSOC no issue. No high output charge sources or loads so high C rate not needed.