One week Sail adventure

Caboteur · Jan 31, 2022

If the anchor light is also LED and you don’t have a fridge, I wouldn’t worry about it. That O/B must have a hand start option. So there is no drama were the battery to fail… just turn all off.
I’d want to monitor the the battery’s voltage and make certain not to go below 12.2V (at rest).
The big consumer is the chartplotter: whether you use it all the time or only in the « tricky » areas will make a difference.

PaulK · Jan 31, 2022

Bringing an extra battery or jump-starter might be cheaper and easier than adding a bigger solar panel. Your existing setup seems to work pretty well.

garymalmgren · Jan 31, 2022

Hi Erbardy
There are a few things to consider.
battery.
Charging rate /system.
Load.

Many people go for a bigger battery or charging system first.
I think reducing or managing the load should be the first priority.
Your load:
LED lights, some cabin fans, bilge pump, electric galley faucet, depth sounder, chart plotter, nav lights and the electric start for out 15hp 2-stroke outboard. The battery is maintained by a permanently installed 75W
is easily manageable, but I notice that you don't have a refrigerator.

LED lights. Headlamps are a good back up and when poking around in lockers are actually more useful.
Cabin Fans, Wind sock for forehatch and sluicing the decks with water helps to cool things down but nothing beats a fan. Running all night will be a drain though.
Electric galley faucet. Fit a foot pump with a bypass valve and extra spigot. This will limit the amount of water that you use and be a good back up when the electric pump fails.
Depth Sounder. Switch it on when you need it. There is no reason to have it on in 100 foot of water.
Chart plotter. Switch it on when you need it. There is no reason to have it on if you know where you are and have a chart.
Nav lights. Only used at night and if they are LED there is not a big draw. Anchor light can be a portable unit with batteries that is hoisted aloft.
Electric start. Used rarely and the engine should be charging the battery when running.

Your battery
We have a 200ah AGM battery
This should be adequate as long as you have the load and the charging organized.

Charging rate /system.
There is a bit of confusion here 75 watts, maybe 50 watts maybe upgrade to 100 watts.
No indication of engine charging.
No 110 volt battery charger.
Plus I do have the solar panel permanently installed, but it is not enough to charge it in one day if the battery is drained.

My first question is, How do you drain a 200ah battery with that load in the first place?
Is the battery so weak/old that it is draining without a load?

As for charging.
If you are staying at marinas (either every night or occasionally) get yourself a battery charger.
If you do not have access to shore power a gasoline Honda generator will do the job as a back up.
These will be of no use if you have a dodgy battery.

Still a while to go before summer, so have fun preparing and planning.

gary

dlochner · Jan 31, 2022

A 200 ah battery is pretty large, or do you have a couple of group 31s?

Although the bank is 200ah you only have 100ah of usable capacity, when the battery's state of charge goes below 50% sulfating increases and battery life is dramatically shortened.

To answer your question, you need to know how much power you consume on a daily basis. How much current do the lights take, the VHF, anchor light, stereo, etc. Then estimate how many hours each device is being used. From this a daily amp hour budget can be developed.

Once you have the budget you will know how much charging capacity you will need. Due to the inefficiencies of charging lead acid batteries (AGMs are lead acid) add 15% to the daily consumption. If you use 20 ah a day, you will need to put back at least 23 ah.

Solar panel output is determined by a lot of variables, few panels spend much time at their nominally rated output. A rough estimate of a panels production is three times the nominal output; a 50 watt panel would provide 150 watt hours or about 12 ah of power.

With this information the decision on panel size is simply a matter of arithmetic.

An AGM battery would not be my choice for your application. They are very sensitive to being a partial state of charge. Leaving them for long periods (a few days or weeks) in that condition with dramatically shorten their life. If you are unable to return them to a full charge at the proper voltages, the batteries will rapidly lose capacity. A good Flooded Lead Acid battery would be a better cheaper choice.

jssailem · Jan 31, 2022

200AHr batttery. It is expendable (meaning you are not worried about keeping the battery after the trip.

175AHr / 20 amp per 24 hrs. = 8 days of power. Battery might have a little left in reserve.

These systems are never 100% accurate. I'd say you could make it if you limit your consumption to 20 amps a day.

Have you added up your consumption to get an energy budget?
i.e the Caframo Sirocco II 12V fan has this power consumption.

CURRENT DRAW ON LOW	0.06A
CURRENT DRAW ON HIGH	0.35A

If you run it 24 hours at High to keep cool you will consume 8.4 amps or nearly half of your 20 amps / day budget.

The numbers are your friend.

DArcy · Jan 31, 2022

My old C&C27 had two group 27 90A-hr (IIRC) batteries. They were on a 1/2/Both switch and I used one at a time while the engine was off. I could only last about one day on one battery at anchor before needing to start the engine and charge. A mix of incandescent and fluorescent lights, no refrigeration, no chart plotter, two smallish fans, an electric water pump and a couple hand held devices charging.

At the dock I used a NOCO Genius 7.5A charger which was installed in the battery compartment but I just ran an extension cord to the charger from the shore, not through the installed AC system in the boat. That boat had an overhanging gap in the main hatch that allowed the cord to run through.
I would guess 200A-hr will not last a week. Depending on how much motoring you do it may be enough.

An AGM battery wants to be charged quickly which is why I wouldn't recommend it for your setup. They are really only good if you have a generator or high output alternator on your engine. If your charging sources are solar and/or a small alternator you are better off with flooded cells.

rgranger · Jan 31, 2022

garymalmgren said:
Anchor light can be a portable unit with batteries that is hoisted aloft.

There was a lot of good stuff in this post.... the wind scoop was one that I've used with great success...and will cool off the cabin faster than fans if you have a breeze. It also keeps the mosquitos out of the cabin. I have enven fabricated one out of a beach towel and my boat hook... tied the corners of the towel to the hook, looped a line from the hook to the forestay and then hoisted it with the jib halyard. The aft corners were tied to deck hardware just behind the forehatch...

But the anchor light suggestiong is spot on... not only will this save your house battery but it is also safer and more useful. If people are poking around in a fog ... they are not looking up to see if there is a light high above their head... but they will see your light hanging from your boom. AND it makes sitting in the cockpit in the evening a bit nicer...

I would also suggest citronella candels. I typically burn one in my cooking pot. The pot is just in case I catch a wake and the wax spills.

rgranger · Jan 31, 2022

Also, the next time you upgrade your outboard, I'd suggest the Tohatsu sail pro. It is pull start but it does come with a 6 Amp alternator for a second way to charge your batteries.

David in Sandusky · Jan 31, 2022

In the Islands/West End of Lake Erie, every marina has shore power. A adapter plug (in case the shore power system does not have 110 plugs like those in a house) an extension cord, and a battery charger will allow you to charge your battery every time you are in a marina. If you limit yourself to lights, depth sounder, and water, you should be OK anchoring out or mooring for a night. A smart phone with Navionics or handheld gps will give you chart plotting that doesn’t draw on your battery. And you should get by pumping the bilge in marinas.

That would allow your planned tour of the Islands without major investments. Then you can design and implement an electric system knowing you cruising needs.

Davidasailor26 · Jan 31, 2022

A 200aH battery at 12 volts is unusual, and must weigh quite a bit. I’d say you’re on the borderline with that battery for a week. With those devices you’re probably looking at a steady state load of 3 amps or less when running the plotter and maybe an amp overnight. Figure on that being about 48 amp hours per day. You really shouldn’t use more than 100 of your 200 amp hours, but if this is a one-time trip not a regular plan a little more won’t hurt. The other good news is that batteries are generally rated at their 20 hour discharge rate. You’ll be burning slower than that so you should have effectively a little more capacity. Plus you could probably figure on your solar panel putting about 15 AH per day back in. So you’ve got a net daily use of about 35 AH conservatively. I’d be comfortable with that for about 4 days.

I’d probably pick up a charger and extension cord to be safe if it were me. For a one time use it doesn’t need to be a fancy 3 stage marine installation.

AGM isn’t the ideal chemistry for this use, but for one trip it’ll be alright. I would add that you should check the battery beforehand to make sure it’s really still capable of holding the capacity you think it has. It would be sad to find out a couple days into your trip that your 200 aH battery only has a usable capacity of 80 aH.

Capt Robbie · Jan 31, 2022

if you plan to do weekend trips a lot which I would hope. Then purchase a jumpstart pack and bring it with you for the weekend just in case you need it. The solar system seems to work well for you as a weekly charging system. Unless you are looking to completely upgrade everything as part of a long term boat venture, I think the jumpstart pack should suit you for now

Jumpstart · Jan 31, 2022

Harbor Freight 20amp 50’ power cord. 110v to 30 amp adapter- Amazon. 12 amp marine smart charger. Only 3 places to anchor or moor in the islands area, the rest are docks with power. You are not going long distances especially if you are launching from Sandusky or Port Clinton. Have paper charts for planning. Navigation errors around the islands are limestone ones

dlochner · Feb 2, 2022

Erbardy said:
Thank you so much everyone. I plane on installing AC shore power given all the feedback. I will install enough for a receptacle in the galley and another under the galley countertop to power a marine smart charger.

Do your homework on installing AC circuits. Done correctly they are perfectly safe. Done incorrectly, especially on freshwater, they can be lethal. If you have any doubts hire a marine certified electrician. Most shore based electricians do not understand the marine environment and may wire the boat incorrectly creating a lot of problems

Also, it is better to hard wire a charger than to use a receptacle. More secure and fewer problems with corrosion.

DArcy · Feb 2, 2022

I would suggest going for the NOCO 10A charger. The 5A won't charge your 200A battery overnight, the 10A would get you much closer to a full charge from 50% SOC. Really, you should have a 40A or 60A charger for that size AGM but 10A will likely keep you going for your use.

One week Sail adventure

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SBO Weather and Forecasting Forum Jim & John

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