Marine battery and solar panel questions

[Bad Obsession]

If you can spend the money I would suggest a Soliban Panel and a Genasun GV-10 controller. Get a MPPT controller at the least but not all controllers are equal. The Genasun is supposed to be one of the best for smaller panels (100 watts).

Unlike the other people I definitely stand behind using the 100 watt panel. Think of it, you may have a few cloudy or rainy days on a trip. If you size your panel to just keep up then you can't put back if you drain it down during bad weather days.

 

[Bad Obsession]

There is a shot of my panels on the bimini.

 

[fred1diver]

I'm planning a trip to the georgian bay, I plan to be on the water between 7 and 10 days, I'm starting to compile a list of my equipment usage and amps drawn, I mostly use my fish finder, vhf (planning to wire both together soon) those are on most of the day, in the evening the anchor light will be on and some led lights inside the cabin, I will have to recharge my phone every 2 days (or maybe more) but the iPad will be used a lot by my son so it'll need a charge or two every day. That's my main electrical usage, I'll measure the current drawn and make a list this week.
I unfortunately don't have a bimini at the moment, not sure if I'll ever install one, my boom stands pretty low and I trailer sail my boat a lot so dismasting with a bimini seems troublesome, I have my Bbq on the aft starboard pushpin with doesn't leave me much room for a solar panel, even less for a big one

 

[Chief RA]

A small solar panel is kinda like a small boat: after you get it you will wish you had bought a bigger one! Chief
PS: Forgot to say, besides the DC reefer I also have a DC TV with signal amplifier/antenna. Antenna runs up the mast on sail slides while in port. TRICK!
Chief

 

[Stu Jackson]

I have my Bbq on the aft starboard pushpin with doesn't leave me much room for a solar panel, even less for a big one

Fred,

One of the "places" folks suggested you "visit" is this one:

http://www.pbase.com/mainecruising/solar_panel

Answers all your size and mounting issues.

Hope you got "into" my earlier links.

Good luck.

 

[Stu Jackson]

For BAD OBSESSION

Matt,

Your boat is drop dead gorgeous. I never realized how big a cockpit you had. Heck, I bet you don't miss your C30 at all!

 

[Bad Obsession]

I miss standing headroom, separate head, stove that I can use underway, and a few other things. Saga is turning out to be a very strong pocket cruiser.

Here is how she sails!

 

[Bad Obsession]

There are tons of ways to mount things...

You may also want to take into consideration weight. If you put extra weight in one place it can change the trim of the boat. This is the fun of sailing small boats. When I upgraded my battery bank I did end up putting about 30 pounds of concrete in a bucked in my anchor locker to balance out the batteries and the outboard.

 

[druid]

We're talking about a 23ft ft boat here, folks. Outboard (probably manual start) so I don't see the need for two batteries (typically one for "house" one for "starting"). No fridge, no A/C. Probably no Autopilot. The only draws would be GPS, sounder, maybe lights. So, a Grp 24 would probably do, Grp 27 would be better if it would fit. It's actually hard to get a solar panel in the 50-Watt range since 80-100W panels are so cheap. But a 80-W panel would be hard to fit on a 23 ft boat and really not needed (I have a 90W panel on my 32-ft and it is enough even for a fridge). I'd say something around 40-50 W would be plenty, mounted on the stern rail or not mounted at all - just place it so it's facing the sun!

druid

 

[Bad Obsession]

Druid, I have a 23 foot boat. My boat is outboard, manual start. I did two GC2 batteries to have a beefy house bank because I stay out on the hook for quite some time. I have 215 amp hours (maybe more because I forget my exact number) for my house bank.

Either way, my trip this year featured quite a few cloudy and/or rainy days. In 12 days I NEVER went into a dock. I managed to keep my batteries up through my 100Watt solar panel and big house bank.

As I said earlier, it depends on what you are running. I have the tiller pilot, gps, vhf, stereo, and other things running a lot. My system is beefy enough that I could do an overnight trip with Nav lights constantly on and not worry about draining too much.

It is all about how you intend to use the boat. Mine gets long trips and I have a lot of stuff I run. Still, with my set-up I don't think I would like to add an Refrigeration unit because of the constant draw. It would be nice to have but I don't mind using the cooler, for the most part. Remember, the outboard doesn't charge the batteries worth a hoot. You need a good bit of solar to maintain if you run a lot of electronics, even better a larger solar panel to help keep things up if you run into bad weather for a few days.

The only good option on a smaller boat is a flexible panel. There are a lot of ways to put them on and you can change where you keep them. The other nice thing is that the weight is quite a bit less.

 

[Stu Jackson]

It is all about how you intend to use the boat.

Oh, so true. It's about time folks started understanding that one size does not fit all.

BO's description of how he uses his boat is extremely important.

 

[Bad Obsession]

Stu, to add to that I will add this....It isn't necessarily the size of the boat but the size of the job the boat suits. If you have a dock queen and you hit a marina every night your demands are different than a cruising boat that stays off the grid. There is nothing better with either situation, it is just the job the boat is doing.

It is just like when people buy boats. Most people think about what they plan or want to do with the boat. The fact of the matter is it is better to understand how you will really use it. I would love a big blue water cruiser but it would be overkill for the coastal cruising that I do, for the most part. Before you buy a boat, upgrade a system, or do anything you should think about how you are really going to use it and what your real demands are.

 

[The Garbone]

Garbone: 200 watts of solar coupled with about 200ah battery bank sounds like a good basic self sustaining system.

I tend to leave the 50watt panel on the companionway hatch and keep the boom sheeted in the opposite direction to limit shading when I am not on the boat. I have a length of paracord run thru the frame that I tie to the traveler or winch in the event of a windy day and me not being near the boat. Has saved me as I have gone sailing forgetting to stow the panel below, tacked and had the panel slide off and the power cable and paracord kept it from going over. Ooopss..

I have about 300ah of batteries and they are always floating nicely. The nice thing about an inboard now is the ability to throw 30amps at the battery for an hour or so at the end of a trip when dropping the hook or motoring into the slip.

This was the 15watt panel on our C27, the grill base is just visible on the port side of the pushpit. For what I paid ($100 or so) for it in 2013 you can get 50watts or better today. The most expensive part was the the 2 Magna grill brackets I attached it to the rail with. $$$$

 

[Bad Obsession]

Fred, I noticed that you talked about doing some wiring. I totally rewired my boat since the old wire in it wasn't pre-tinned. There was also some questionable runs that the Previous Owner did.

You may want to think about how your current boat is set-up for the wiring. Our boats, being smaller with less systems, are pretty easy to wire and it doesn't take a lot of time to make progress. One advantage to the wiring upgrade is that you know what you have and you know that what you have is right. I know were ever bus bar and every wire connection is located. I also had to add in a second fuse panel to accommodate my electronics. Off of the fuse panels I have some leads running to a bus bar.

For example: My Nav/Com switch. The wire run is from the battery to the fuse panel. From the fuse panel to the Nav/Com switch. From the Nav/Com switch to a bus bar. From the bus bar I have my VHF, GPS, and Depth Finder running.

I also created a very large negative bus bar where all of the negative wires run. I used, for most things, MaineSail's trick for labeling wires so I know what is going into the bus bar.

Below is the two fuse panels. Higher load items have their own switches. The switches that go to a bus bar are Nav/Com and Cabin (Cabin is my 12V lights and my 4 12V outlets). Auto (auto helm) is just wired to the plug for the auto pilot. The same goes for Water (water pressure system). It is all very simple and basic but peace of mind.

 

[Meriachee]

And that truly is the name of the game. Your boat, your choice. We used to get grief from "real" sailors at the coast because we had an M26c, with solar. In 1993 that generated more than a few conversations in the places we went.
Not so uncommon anymore.
(and there's still an active M26 group who regularly attack the Strait. )

 

[druid]

Yup, and I spent weeks off the dock on my Cal 25 with a Grp 27 battery and a 45W panel. I do tend to go "minimalist" though...

druid

 

[Ballast boy]

I am currently 'living the dream' on a 33' cruiser racer and make all my electricity using solar panels. This isn't all that hard as I am in the Med. I am spending 9 or 10 months of the year sailing at the moment. I would say that you need to match the wattage of the panel to the battery capacity and the wattage of what you are trying to run. What tends to happen if you are using a large, or several large panels and have too little battery or too little load is that the voltage shoots up quite quickly and the charge controller disconnects them. This can mean that the panel is in effect switched off before you float or condition the battery. I have also found that fixed panels are rarely at the right angle or not partially shaded, which can be a bit of a disaster for monocrystalline panels in particular but just generally massively reduces output. I have ended up making rigid panels out of 'semi-flexible' panels using a carbon/ foam sheet for one set and a carbon frame for the other. I keep the area directly behind the photocell open to help it cool as getting very hot can be a problem too. We have waterproof deck plugs and deploy them by tying them on at the best angle. We monitor the charge rate and voltage using a battery monitor made by NASA marine and add more panels depending on what we are doing. Economics come to play here because it is generally cheaper to by a single 100w panel than 5 x 20w panels but given the choice, I would probably opt for several smaller ones wired to your controller in parallel and switch them on as required to give 0.5 to 1.5 amp charge over what you are actually drawing to maximise the long term life of your batteries. We have a total of 380w and run all our navigation/autopilot/water maker etc. The most energy intensive item is a small ice maker run off an inverter, which takes pretty much all we can throw at it. If we didn't want to run the ice maker (and we really only churn out ice at anchor) we would probably be fine with about 180w. Obviously in less sunny places, or winter time you might want more.

 

[Chief RA]

BB: The controller takes care of battery current input so manual manipulation is unnecessary. Angle of panels can effect charge but surprisingly it does not change much unless you are way out of angle with the sun. Shade does slam most types of panels. After full battery bank charge that is the time to run your TV, Ice maker, Microwave etc as you can use the otherwise excess solar power generated that your system would not otherwise be using. Chief