Can I Run A 12V Outboard Off My Solar Array

[Cotemar]

Originally Posted by Colin A

Quick question, what's the reasoning behind the 80V battery instead of buying a 12V one? I assume the energy density is good but I would assume the losses in dropping to 12V would negate some of that?

We use this electric motor on our 10 foot working dinghy that we use to go back and forth to our mother ship on a mooring.

Our Mother ship has a HighField 11.5 foot rib with a Suzuki 20 hp for our island cruising dinghy.

We had used a few different batteries, but they just did not hold enough energy.

The 80 volt Lithium Ion Battery is so light weight and has a high energy density that it works perfect for our 10 foot dinghy.

It has 40 -18650 batteries inside which are the same ones they use in the Tesla S and E models and Tesla Power Walls.

I use this same 80 volt Lithium Ion Battery in my GreenWorks Pro 21 inch lawn mower.

[Adelie]

Originally Posted by SV DestinyAscen

. . .
Ultimately do whatever you want since it is your boat. But it's a bad habit to mess with good systems for no reason or improvement and ignore advice.

Unless the advice is bad advice in which case please do ignore. The trick is figuring out what advice is good, mediocre, indifferent or bad. Good luck with that part.

I agree that you don't want to use a starting battery from the engine unless it's really a deep cycle but even then I'd be leery.

[jheldatksuedu]

It depends on the amp draw of the motor, and the output of the panel, basically without a battery in the circuit there is a chance that the solar array could put out more voltage than the motor could take and burn something up in the control part of the motor. With the battery in the circuit to absorb the excess when the motor is not using the power would protect the control circuits in the motor.

[StuM]

Originally Posted by Gone2long

I get the point(s), and they make sense; but, just for argumentation's sake, one way to get around damaging either battery would be to disconnect the charged battery when I replace the discharged battery back into the bank. Would work, no?

Yep, if you regularly swap the two batteries and forget about ever treating them as a bank, that would be work.

[brownoarsman]

If you were to do this, why not switch the wiring so you have a 3-battery house bank and a 1-battery starting bank? Then just take the engine starting battery with you, which, from your description, sounds like a deep cycle as no distinction was made between house and engine banks in the original setup. When you run it down, use the house bank to start your motor. When you fry it, switch it out without having to worry about an unbalanced bank. I assume your engine is not large enough that a deep cycle can't start it, and that your bank is composed of 12v batteries rather than 6v ones, and that your boat is wired for 12v.

[mitiempo]

Originally Posted by Badsanta

I like the guy who couldn't understand why putting an alternator on his electric motor wouldn't work.

This is one solution to charging a battery for an electric outboard. This one belongs to a friend. Mine is similar with a 50 watt panel and a 55 lb thrust Minn Kota. The panel is installed on a 1" stainless arch that slips into brackets inside the transom. The solar controller is inside the battery box with the Agm battery.



While the Minn Kota uses up to 50 amps at full throttle I can idle along slowly using 1 - 2 amps.

[knockabout]

dick smith motored a multi-hull around the world using solar panels, a battery bank in each hull and electric motors / you may be better off with a battery suited to your outboard fixed to your dinghy and charged from your solar array by attaching a cord when your dinghy is in it's davits or along side .

[Gone2long]

Originally Posted by mitiempo

This is one solution to charging a battery for an electric outboard. This one belongs to a friend. Mine is similar with a 50 watt panel and a 55 lb thrust Minn Kota. The panel is installed on a 1" stainless arch that slips into brackets inside the transom. The solar controller is inside the battery box with the Agm battery.



While the Minn Kota uses up to 50 amps at full throttle I can idle along slowly using 1 - 2 amps.

Really nice idea that I will look at as a long term solution; but I doubt I could find any of the components where I am, and facing possible 100% import taxes, shipping costs, and potential customs bribes, not sure I could afford it.

An extra, however, would be that nobody out here would know what the heck it was, so they probably wouldn't try to steal it : )

G2L

[Gone2long]

Thanks for the info and photos. Another great idea that I will look into for future reference, however, as noted in previous posts, access and cost are issues.


Regards,


G2L

[Gone2long]

Originally Posted by brownoarsman

If you were to do this, why not switch the wiring so you have a 3-battery house bank and a 1-battery starting bank? Then just take the engine starting battery with you, which, from your description, sounds like a deep cycle as no distinction was made between house and engine banks in the original setup. When you run it down, use the house bank to start your motor. When you fry it, switch it out without having to worry about an unbalanced bank. I assume your engine is not large enough that a deep cycle can't start it, and that your bank is composed of 12v batteries rather than 6v ones, and that your boat is wired for 12v.

Another good idea, but the answer to your question on changing the wiring is "because I don't know how." Also, if it meant moving any of the batteries, that would be a no go. The fact is that the only place I have to store the battery that I will use for the outboard is in the engine bank.

And, actually, that is a very easy place to get to on my boat, since it sits under my companionway stairs, which easily lift out of the way. So, whether I switch my charged battery off when charging my outboard battery via my solar array, or whether I charge the outboard battery with my portable generator, the battery to be used for the outboard is gonna stay in the engine bank space - at least for the foreseeable future.

Hope this additional info adds clarity and helps some of the critics up the thread understand the situation a bit better.

In closing, let me thank you for your suggestion. Makes more sense than the configuration I have, but I really wouldn't know how to go about re-wiring things, and to do so is not a priority at the moment.

G2L

[brownoarsman]

Ahh, well that is easily remedied The technical term is wiring the batteries in parallel, positive terminal to positive terminal, negative to negative, with heavy gauge wire. 30 minutes on Google and YouTube, plus a beer, should teach you everything you need to know about the job.

[Gone2long]

Originally Posted by brownoarsman

Ahh, well that is easily remedied The technical term is wiring the batteries in parallel, positive terminal to positive terminal, negative to negative, with heavy gauge wire. 30 minutes on Google and YouTube, plus a beer, should teach you everything you need to know about the job.

Hmm ... I think I get the point. I understand parallel wiring, but I did not think that changing a battery from one "bank" to another would be that simple. If I understand you correctly, all I really need to do is disconnect the + and - of one of the engine batteries and reconnect them in similarly parallel structure to one of the house batteries. Correct?

That said, there are other logistical problems involved. For one thing, the engine and house banks are in different places in the boat, so I would have to do some serious re-wiring, maybe cutting holes in bulkheads, etc. I will post some photos in a couple of days, and once everyone knows what I really have, where, we can take the discussion further.

Appreciate your input. You simple comment has got the neurons firing again, hopefully in, the right direction. Keep talkin' to me.

G2L

[brownoarsman]

That should do it. Of course if the batteries are far from each other there may be drops due to a long wire run; but now we are out of my depth. If your banks are installed anything like ones I have seen, your selector switch will run to one battery on the bank (let's call it the primary) and the other battery on the bank will be wired to the first (let's call that the secondary). So changing the makeup of your bank would be to just remove the secondary battery wiring to the primary starting battery, and wiring the secondary starting battery as the tertiary house battery to the secondary house battery (in parallel).

Then, to remove the primary and now only engine starting battery, one would just lift it out. When you take your photos, however, look at if there's anything directly wired to either one bank or the other. My bilge pump, for instance, bypasses the selector switch and ties directly into my house bank. I want this because even if my switch is off, I want the bilge pump to save the boat while I'm away

So you would need to be careful that you are not disabling critical systems when you remove the engine battery.

When you take pictures, see if there is any labelling on the batteries that would give an idea of capacity, type, etc.

[Gone2long]

Originally Posted by brownoarsman

That should do it. Of course if the batteries are far from each other there may be drops due to a long wire run; but now we are out of my depth. If your banks are installed anything like ones I have seen, your selector switch will run to one battery on the bank (let's call it the primary) and the other battery on the bank will be wired to the first (let's call that the secondary). So changing the makeup of your bank would be to just remove the secondary battery wiring to the primary starting battery, and wiring the secondary starting battery as the tertiary house battery to the secondary house battery (in parallel).

Then, to remove the primary and now only engine starting battery, one would just lift it out. When you take your photos, however, look at if there's anything directly wired to either one bank or the other. My bilge pump, for instance, bypasses the selector switch and ties directly into my house bank. I want this because even if my switch is off, I want the bilge pump to save the boat while I'm away

So you would need to be careful that you are not disabling critical systems when you remove the engine battery.

When you take pictures, see if there is any labelling on the batteries that would give an idea of capacity, type, etc.

Yes; I will definitely not forget primary and secondary nature of the connections when switching things around. Concerning the banks, they are not far enough away from each other to cause a drop in power. The problem is that they are on different levels of the boat, but more on that later.

I understand the capacity etc. of the batteries; will talk about that and other details when I get back to the boat in a few days.

Thanks again for your comments. I think we may have the best solution to the problem within our grasp. Interesting to see how it evolved over the course of this thread (which I never expected to garner this much interest)


Fair winds,


G2L

[Rorzech]

Just get a 2HP gas outboard to back up your 2HP gas outboard and be done with it.