96v boat upgrade

[Alex5008]

This is my current project. I had built this boat for my specific needs of coastal cruising. It is 35', trailer able, beachable, light, fast (35+kts) and has less than 8' bridge clearance. It did everything it was designed to do. Now I want to go farther (maybe the great loop) and tired of filling it with gas. Dont need to go fast, happy with 6kts ( hull speed) .
Currently it has 600watts of solar and 12v battery bank.
I will soon be ordering 12 REC panels at 275 watts each making a 4500 watt array. So far that is all I know for sure because I want to maximize the power and that is what I can fit on the boat.
It does not need much to push it at 6kts. I am figuring less than 10hp will do but will want a little reserve power.
I am asking advice on doing a 96v system because, like I said I want maximum power and efficiency. I have done many simple solar systems before but none were 96v.
Any help would be appreciated.
Dont bother if your going to tell me it can't be done.

 

[John Frum]

I guess you will be looking for a 20 horse power 96 volt dc motor, confirm?
Have you sourced any?
If yes, how efficient are they?

 

[rin67630]

96V DC in a wet environment... Are you tired of life?
96V DC on a boat is simply lethal and can build really long sparks that will kill you without mercy.

 

[Alex5008]

They do it in cars so I know it can be done.

 

[Alex5008]

I guess you will be looking for a 20 horse power 96 volt dc motor, confirm?
Have you sourced any?
If yes, how efficient are they?

My son maybe can answer that. He knows more about motors.

 

[time2roll]

They do it in cars so I know it can be done.

Might look at some EV conversion kits to adapt into the boat. At this power level an AC variable speed drive might work well.

BTW, Beautiful boat.

 

[jwelter99]

View attachment 53508
This is my current project. I had built this boat for my specific needs of coastal cruising. It is 35', trailer able, beachable, light, fast (35+kts) and has less than 8' bridge clearance. It did everything it was designed to do. Now I want to go farther (maybe the great loop) and tired of filling it with gas. Dont need to go fast, happy with 6kts ( hull speed) .
Currently it has 600watts of solar and 12v battery bank.
I will soon be ordering 12 REC panels at 275 watts each making a 4500 watt array. So far that is all I know for sure because I want to maximize the power and that is what I can fit on the boat.
It does not need much to push it at 6kts. I am figuring less than 10hp will do but will want a little reserve power.
I am asking advice on doing a 96v system because, like I said I want maximum power and efficiency. I have done many simple solar systems before but none were 96v.
Any help would be appreciated.
Dont bother if your going to tell me it can't be done.

You don't want to do 96V in a boat. You will limit the availability of equipment drastically, and tough to find marine suitable equipment. Also 96V DC is a safety issue which needs special precautions when working on it.

Go with 24V or 48V.

Interesting boat - looks like a catamaran type hull. What is propulsion right now? I see an outboard but is it single and what HP to achieve 35 knots?

 

[Alex5008]

You don't want to do 96V in a boat. You will limit the availability of equipment drastically, and tough to find marine suitable equipment. Also 96V DC is a safety issue which needs special precautions when working on it.

Go with 24V or 48V.

Interesting boat - looks like a catamaran type hull. What is propulsion right now? I see an outboard but is it single and what HP to achieve 35 knots?

It had a 250hp yamaha outboard. I already took off the power head and an going to adapt an electric motor to it.
The high voltage is just for the motor. Was going to step it down to run the 12v house system. Other loads are minor.

 

[Alex5008]

Might look at some EV conversion kits to adapt into the boat. At this power level an AC variable speed drive might work well.

BTW, Beautiful boat.

Yes my son had told me that a AC motor might be the way to go.

 

[Alex5008]

Does anyone know how much efficiency i would give up to go with 48v over 96v?

 

[schmism]

Ill napkin math some numbers....
for the sake of ballparking something. Lets your 6knt cruising speed is as efficient at as a model 3. (i think thats a stretch but at least we will be on the conservative side) That is a ~50kwh battery for 250miles of range.

so 4500w*5hrs of sun a day = 22,500wh. so you'll need to be stationary for 2 days of good sun before you could hope to move another 200 miles. And thats with no other electrical loads for those 2 days.

Whatever plan you use it should include a backup generator to provide power for whatever motor you end up useing.

some other napkin math numbers to consider. 1hp = 745w so a 20hp electric =~15kw motor. 4500w = 6hp So the idea that your going to move the boat "only when the sun is out" seems unlikely. I dont see that boat doing much on a 6hp trolling motor.

 

[schmism]

Does anyone know how much efficiency i would give up to go with 48v over 96v?

insignificant in terms of the scale of your project

 

[time2roll]

20hp is about 15 kW or 150 amps at 100 volts, 300 amps at 50 volts. (not including conversion losses) Even running at 10 hp will be significant. How many hours do you expect to run? Do you have the space for these batteries?

 

[John Frum]

Starting with a wild guess of 75% efficiency for the motor.
10 horse power is 7457 watts.
7457 watts / .75 efficiency = 9942.666666667 watts
That is 10kwh every hour.

 

[jwelter99]

I'd talk to these guys, they make a 18kw and 36kw outboard conversion and complete system.

Electric Outboard Motor | Houston | Stealth Electric Outboards

Stealth Electric Outboards Finally! A powerful all electric outboard that will plane your boat!

www.stealthelectricoutboards.com

We are installing twin 36kw in a guys tender this fall when it comes in for refitting.

 

[Alex5008]

20hp is about 15 kW or 150 amps at 100 volts, 300 amps at 50 volts. (not including conversion losses) Even running at 10 hp will be significant. How many hours do you expect to run? Do you have the space for these batteries?

I do have the space. Lots of space. I would be happy only running 2 hours during the day. Some days I plan on sitting still with the AC on. My AC only draws 500watts with compressor running. In my previous boat I was able to run my AC 24/7.

 

[Alex5008]

I'd talk to these guys, they make a 18kw and 36kw outboard conversion and complete system.

Electric Outboard Motor | Houston | Stealth Electric Outboards

Stealth Electric Outboards Finally! A powerful all electric outboard that will plane your boat!

www.stealthelectricoutboards.com

We are installing twin 36kw in a guys tender this fall when it comes in for refitting.

I have looked into electric outboards. I have not found one that will fit my needs. Most try to get on a plane. I will be turning a large diamiter bronze prop at slow rpm. Like everything else I do, I figured on making it myself.

 

[time2roll]

Here is 20 hp 72 volts. Many possibilities.

https://www.elcomotoryachts.com/product/ep-20-electric-inboard/

Although the electric outboard seems closer to plug and play.

 

[Alex5008]

20hp is about 15 kW or 150 amps at 100 volts, 300 amps at 50 volts. (not including conversion losses) Even running at 10 hp will be significant. How many hours do you expect to run? Do you have the space for these batteries?

Most people are not aware of how much power it really takes to push a boat. Its much easier to just over power it.
I built this boat with a fiberglass hull. Cedar frame and aluminum skin for topside. It weighs about 7k lbs. I trailer it. 12' beam and 35' long. It already has everything I need right now, full kitchen, refrigerator, queen bed walk in shower, etc. I will be taking out 4 lead acid gulf cart batteries, 50 gal fuel tank and engine related weight hoping to offset the solar. And lithium.

 

[Alex5008]

Here is 20 hp 72 volts. Many possibilities.

https://www.elcomotoryachts.com/product/ep-20-electric-inboard/

Although the electric outboard seems closer to plug and play.

Inboard configuration won't work for me. It has to be outboard so I can utilize the tilt. It is important for me to be able to beach it. I have used this boat for a season already and it works great. I rarely ever anchor and don't even need a dingy. Draws about 14" of water. I either beach it and tie it to a tree or put down my built in spud anchors.