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Discussion Starter · #1 · (Edited)
I have a 20 foot Balboa that I would like to power for off of the grid use, for week end trips on the great lakes (2 to 4 days).
I have a deep cell battery and a Tohatsu 6hp sail pro outboard.
Sail pro electrical output is 12V 60W 5 Amp.
The battery is an energizer E24DCN Deep cycle marine/RV 675 Amp.
The loads will be navigation lights, cabin lights, depth sounder, am/fm radio, and a hand held marine radio.

Will I need a larger battery? Solar charging? How much will LED lighting help?

There is no electrical power where the boat is docked, currently the battery is only charged by the motor.
 

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You will probably not get enough charging from your engine if you only use it for a few minutes to get in and out of the anchorage/marina to re fill your battery. Do an electricity budget by listing all of your uses, their draw in amps times the hours of expected use and total them up for each day's use. The sum of the trip days use should not exceed half the amp hours of you battery plus any charging you get. Since you don't have electricity at your dock, look into one of those solar panel trickle chargers, that way each weekend starts with a full battery.
Also, look into an led lantern that has its own battery. You can use it in the cabin and as an anchor light.
John
 

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my .02 on it.

You should be fine with a small solar panel, probably even something as low as a 50 watt panel will keep up with you with what you're using. Probably even less. I run the same, nav lights at night, cabin lights, 7" charatplotter on constantly underway, and a fixed radio. I also usually have my phone charging, or there have been other nights I've watched a few hours on a 24" LED tv streaming from my phone. And I have yet to knock the bank down to where the 100w panel hadn't topped it back off in early morning. Even something smaller that can top you off during the week should easily hold you over through your trips, especially if you're able to leave it hooked up while out there to let it keep up with you.
 

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The 675 ah rating has to be seriously misleading. That's probably at a trickle draw of something like 1amp. It's not linear math. As you draw more amps, the total amp hours available declines faster.

In any case, for just a couple of days running nothing but lights and a radio, I would expect running your motor for an hr or two per day would do the trick, even if in neutral. Although, if in neutral, you'll want to bump the rpms a bit to get a better charge from your alt. If that's unappealing, get a portable solar charger.

Have a great time!
 

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Mermaid Hunter
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I have a 20 foot Balboa that I would like to power for off of the grid use, for week end trips on the great lakes (2 to 4 days).
I have a deep cell battery and a Tohatsu 6hp sail pro outboard.
Sail pro electrical output is 12V 60W 5 Amp.
The battery is an energizer E24DCN Deep cycle marine/RV 675 Amp.
The loads will be navigation lights, cabin lights, depth sounder, am/fm radio, and a hand held marine radio.

Will I need a larger battery? Solar charging? How much will LED lighting help?

There is no electrical power where the boat is docked, currently the battery is only charged by the motor.
You have a pretty big battery. I looked up E24DCN and didn't find anything to confirm the battery size.

Assuming you have the battery capacity correct here is the order I would invest in:

1. Get a small battery charger. It doesn't have to be fancy although a decent three-stage charger of 10 to 20 amps would be nice. I got that your dock doesn't have power; if you are not going out every single weekend it may make sense to get a transient slip Thursday night into Friday and plug in the boat to make sure the battery is fully charged.

2. Assuming the E24DCN is a wet battery get a hydrometer, a funnel, and a couple of gallons of distilled water. Keep your wets properly watered and use specific gravity to keep track of state of charge (SOC). Voltage is simply not a good way to track SOC. Specific gravity takes a few minutes but is much cheaper than a good battery monitor.

3. Solar panels and a decent (not fancy) charge controller will keep your batteries topped up even as far North as you are as long as you don't have a lot of shading to be concerned about.

Trying to charge off your outboard will cost a lot of money and gas. It doesn't hurt to have the outboard alternator hooked up properly. It will make a contribution.

Converting to LED lights for anchoring, cabin, and possibly navigation lights will help reduce power consumption. Make sure your handheld VHF is fully charged before you leave. AM/FM radio power consumption is higher with volume - bear that in mind.

Enjoy your trips.
 

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Discussion Starter · #7 ·
Than you everyone for the input. I will move the solar panel and LED lights up on my list of up grades.
As for the battery, the tag said 675 marine cold cranking amps not amp hours. There was also a rating for RC minuets of 140. A little investigation resulted in the following definition. "Reserve capacity is the number of minutes a battery can maintain a useful voltage under a 25 ampere discharge."
I have a 6V LED flash light on board, but A LED lantern sounds like a really good idea.
 

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Morgan,

CCA is a measure of the maximum number of amps the battery can put out for a very brief period of time (.1-.5 seconds). Amp/hr is a measure of how many Amps the battery can put out for a long period of time. They are radically different, like the difference in a sprinter and a marathon runner.

I can't remember seeing CCA even posted on a true deep cycle battery, though there may be a few with it on there somewhere. My guess is you have a hybrid, which will likely work for your situation, but if it ever dies get a true deep cycle.
 

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For your next battery, change to a group 27 deep cycle battery of around 100 amp hours which will give you 50 usable amp hours. There are very expensive versions of this battery, but exide makes one that can be had for about $100. Many people think they need a "starting" battery, but a deep cycle can start your outboard and give you more useable amp hours than even a "dual purpose" battery.
I suspect that given you do not have electricity at your slip and depend on the outboard's alternator your battery has been compromised and while it will run the lights and stereo, it may soon fail to start the engine, which is the big power draw.
And I repeat, do your power budget first, spend money second.
John
 

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I have rarely seen an outboard you would use on a 20 ft sailboat that was electric start a small solar panel would be great I use a ten watt one that plugs into CIG lighter older but works good
 

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I second the idea of a small solar panel. There's nothing like going to your slip after a week's absence and finding your battery is fully charged.

On my Victory 21, I had a big flexible panel on the coach roof, tied to the grab rails on either side. Back then I didn't have a charge controller, but here on Sailnet the consensus is that you need one to protect your battery, even with a smallish panel.

Solar will keep everything topped up. Your motor will help when you are actually making a trip. (Let's face it, we all motor more than we initially expected to.) Between the two, you'll be in good shape.

LED lights when possible. (We've swapped out over a dozen incandescent bulbs on our boat over the last few years.) You could even use the puck-type dinghy navigation lights that have a magnetic attachment and run off AA cells.

Regards,
Brad
 

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I would echo all the LED comments. I switched all the lighting on my Balboa 27 over to LED, and can run every light on the boat every evening (5-6 hours a night) for a week before even starting to dent my single Optima deep cycle.
 

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50w panels, at your latitude, should provide roughly 15 ah a day of charge on average.

That's what you need to get your daily usage down to. LED's are the way to do it. No need to go expensive on it, your single largest draw is going to be your anchor light. Replace it with a simple hanging LED on your forestay, sold by Defender for under 30 bucks. They draw .2 amps or less, your 'normal' old anchor light is pulling up to 3 ah.
Figure any most of the interior lights are pulling 1 ah, on a 20 footer you don't need more than one or two lights. You can swap most light bulbs of the G4 type with a realitivly in-expensive LED make to fit in the same socket. Again, those will take you from 1 amp per hour to one tenth.
Keep your radio/stereo/vhf and what not use to a minimum and you should be fine.

Once a month or so you should take the battery home and fully charge it, and find yourself and inexpensive battery monitor as well.
 

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I agree about the LED lights. You'll save a lot of amps. Get them on E bay or Amazon, not a marine supply place. I just got a 10 pack of bulbs for my cabin lights for $29 shipping included as opposed to $42 EACH at Defender! Even if they don't last as long, which still should be a really long time, how can you turn that deal down?
 

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50w panels, at your latitude, should provide roughly 15 ah a day of charge on average.

That's what you need to get your daily usage down to. LED's are the way to do it. No need to go expensive on it, your single largest draw is going to be your anchor light. Replace it with a simple hanging LED on your forestay, sold by Defender for under 30 bucks. They draw .2 amps or less, your 'normal' old anchor light is pulling up to 3 ah.
Figure any most of the interior lights are pulling 1 ah, on a 20 footer you don't need more than one or two lights. You can swap most light bulbs of the G4 type with a realitivly in-expensive LED make to fit in the same socket. Again, those will take you from 1 amp per hour to one tenth.
Keep your radio/stereo/vhf and what not use to a minimum and you should be fine.

Once a month or so you should take the battery home and fully charge it, and find yourself and inexpensive battery monitor as well.
I'm going to be my usual pain about units. Rewriting Chuck's post with the proper units, with my comments in curly braces:

50w panels, at your latitude, should provide roughly 15 Ah a day of charge on average.

That's what you need to get your daily usage down to. LED's are the way to do it. No need to go expensive on it, {N.B. be careful in going to cheap on LEDs - decent quality current-regulated units will pay for themselves in reliability.} your single largest draw is going to be your anchor light. Replace it with a simple hanging LED on your forestay, sold by Defender for under 30 bucks. They draw .2 amps or less, your 'normal' old anchor light is pulling up to 3 amps. {N.B. I like direct replacement LED anchor lights with built-in light sensors like those from MarineBeam; my old incandescent anchor light drew a little over 1 amp. I run the masthead LED and a cockpit level Davis MegaLight LED.}

Figure most of the interior lights are pulling 1 amp each, on a 20 footer you don't need more than one or two lights. You can swap most light bulbs of the G4 type with a relatively in-expensive LED made to fit in the same socket. Again, those will take you from 1 amp to one tenth amp.
Keep your radio/stereo/vhf and what not use to a minimum and you should be fine. {N.B. multiply current draw in amps by the number of hours the device is on and you'll get the energy consumption in amp·hours (Ah)}
 

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Hi Morgan,

My electrical set up, complete, has cost over $10,000 and I can go off the grid for as long as I like. Obviously its crazy to invest anything like that for a weekend cruise. But if you look beyond some of the advice here that suggests you buy this and that, you might be able to come up with a creative solution that costs very, very little.

A bucket of water in the freezer at home on Monday, start just 1/4 full and each day add a bit, by Friday will be a block of ice that will last till Monday on the boat.
Instead of LED lighting have a look int he hardware store for an LED lantern. I buy them for $6 each, they have a torch at one end and a lantern in the handle. 3 AA batteries last 300 hours!
With your boat battery, instead of buying a whopper like I need you might be able to buy one that you can carry home and put of a $30 trickle charger. But will you need much of a battery at all? The depth sounder wont take much power, hand held VHF can be charged at home during the week and wont use much on standby... As for the AM/FM radio they acually dont draw much either (you could sing to yourself) but on the water and at night on anchor I prefer the silence and the sounds of nature. FM music can be butt shoved with glory!

Perhaps try some of the ideas like that, and creative ones you think up, for a few weekends and see what works and what doesn't and which ones you really, really, need to spend money on.

By the way, a fuel Hurricane Lantern puts out a warm glow, smells like a boat should and can really make a nautical experience... :)
 
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