Andre Flocks
New Member
I am in the process of designing my second electric sailboat!
My first project was done about 3 years ago, a byproduct of COVID season. I converted a 25 feet sailboat to electric power. I am not an electrician, I have learned everything I know through online research and trial and error.
On that first project, I decided to build my own batteries using 280 AmpH EVE prismatic cells. The boat had an electric Outboard motor powered by a 48V battery bank (with 16 cells in Series) with an Overkill Solar BMS. Using the same type of cells I also built 2 additional 12V banks also with Overkill Solar BMS that were connected in parallel (560 AmpH). I used the 12V system to run everything else on the boat (Lights, Amplifiers for Speakers and Subwoofer, a small fridge and a Renogy 3000W inverter).
That setup served me well and was appropriate for the size of the boat and for the use I made of it. I live on a Floating home on a lake and the sailboat is docked to the house. I use it often just to motor around the lake, but sometimes I venture further to explore other lakes or even out to sea and don't always have a chance to put up the sails for some or all of my route. Bottom line, with this setup on my first boat, I had an autonomy of about 7 hours at "full throttle", and that felt like the right amount.
Meanwhile, I bought a bigger boat!
I have bought a Catalina 30 Sailboat, which is a bit longer, but much wider. This makes it a much more robust boat, with potential for new adventures. My first step, naturally, is to remove the 25Hp Diesel engine that it has and install an electric motor and some batteries instead. This boat has an inboard motor connected to a shaft. There are several electric motors available in the market for this sort of application and after some research, I know I am most likely to purchase a 15Kw motor for my application. I think that the only spec worth calling out is that a motor like this will need to draw 300A continuous when operating at full throttle, which is important to keep in mind when deciding on the battery setup.
My initial plan was to build my own batteries again. But as I did some research I found that there are new options in the market worth considering. I have a little bit more $ available to work with this time around, and my priority is to make a really cool and reliable system. My main constraints have to do with weight and space. I will remove some weight from the boat (diesel engine and tank), but will add some too (electric motor, batteries, inverter…). I have done some math and given that I have some good margins to work with, I am not too worried about total weight. However, I do need to consider the positioning of those new components in the boat for weight and balance reasons.
Because the boat is docked to my house, my ultimate vision is to use it as the house's battery bank when it is docked to it. This way I can connect the boat to additional solar panels on the house, and by having a good inverter in the boat, it can power back some loads of the house.
Now that I have shared general context on this project, I wanted to share with you what I am considering and would welcome any suggestions/ comments/ ideas that you may have based on your own experience.
Batteries:
Connect in series 4x 12V EPOCH LiFePO4 batteries (460Ah) to build my 48v system.
12V 460Ah LiFePO4 Battery | Group 8D Size, IP67, Heated, Bluetooth & Victron Comms (epochbatteries.com)
If I were to build my own battery, I would likely double my prior system and have 2x48V batteries in parallel with 560AmpH capacity. Building my own gives me some flexibility on the shape of the overall battery, which helps with positioning on the boat. It is also the lightest option, but at the expense of effectively having less protection to the cells.
I have looked at 48V battery options like EG4 server rack or wall mounted (~200AmpH capacity). Those are essentially the same concept that I was going to build, but done professionally with all sorts of features included, s.a. breakers, fuses and communication ports. I could connect parallel some of these to get a bank of 400AmpH. Neither of these batteries are rated for marine use, but neither would be my DIY batteries…
Meanwhile, I came across these 12V EPOCH (460AmpH), I could connect 4 in series to have a 48V system (460AmpH). These are marine rated and seem to be robust and have all the main features that I value. My only concern at this point with this idea is that I will likely have to spread them a bit in terms of positioning in the boat. i.e. 2 in one place, and 2 in another place. That would mean that I would have to use some thick conductors to connect them and form my 48V bank. That doesn't sound as effective as having a battery bank that is made up of batteries that are all connected by shorth connections.
Detail: These EPOCH batteries have Victron Comms built in. I assume/hope that they can also connect to other components, like EG4 inverters, but I am still investigating that..
Inverter:
EG4 6000XP 48V 120/240V Split Phase | All-In-One Solar Inverter
EG4 6000XP Off-Grid Inverter | 8000W PV Input | 6000W Output | 480V VOC Input
I would like to have an all in one inverter, charger and MPPT controller. From my research so far, this seems to be the most interesting option. I just need to confirm that I can connect the communications from the EPOCH batteries to this inverter.
Secondary boat systems
I still haven't decided if I want to have a separate 12V bank like I had on my previous boat to power secondary systems. My rationale for having those 2 different banks in the past was:
Reliability - By having the 48v bank dedicated to the motor only, there would be no risk of something else draining the battery invertedly and leaving me without a way to "move".
Convenience - Powering the lights is easy, I could get a step down converter from 48V to 12V and power them. But those step down converters are very limited in how many Amps they can handle, and I would quickly have issues connecting things like a fridge or the music amplifiers with it. So having a 12V bank made all that easy.
I would love to hear any comments! Thank you
My first project was done about 3 years ago, a byproduct of COVID season. I converted a 25 feet sailboat to electric power. I am not an electrician, I have learned everything I know through online research and trial and error.
On that first project, I decided to build my own batteries using 280 AmpH EVE prismatic cells. The boat had an electric Outboard motor powered by a 48V battery bank (with 16 cells in Series) with an Overkill Solar BMS. Using the same type of cells I also built 2 additional 12V banks also with Overkill Solar BMS that were connected in parallel (560 AmpH). I used the 12V system to run everything else on the boat (Lights, Amplifiers for Speakers and Subwoofer, a small fridge and a Renogy 3000W inverter).
That setup served me well and was appropriate for the size of the boat and for the use I made of it. I live on a Floating home on a lake and the sailboat is docked to the house. I use it often just to motor around the lake, but sometimes I venture further to explore other lakes or even out to sea and don't always have a chance to put up the sails for some or all of my route. Bottom line, with this setup on my first boat, I had an autonomy of about 7 hours at "full throttle", and that felt like the right amount.
Meanwhile, I bought a bigger boat!
I have bought a Catalina 30 Sailboat, which is a bit longer, but much wider. This makes it a much more robust boat, with potential for new adventures. My first step, naturally, is to remove the 25Hp Diesel engine that it has and install an electric motor and some batteries instead. This boat has an inboard motor connected to a shaft. There are several electric motors available in the market for this sort of application and after some research, I know I am most likely to purchase a 15Kw motor for my application. I think that the only spec worth calling out is that a motor like this will need to draw 300A continuous when operating at full throttle, which is important to keep in mind when deciding on the battery setup.
My initial plan was to build my own batteries again. But as I did some research I found that there are new options in the market worth considering. I have a little bit more $ available to work with this time around, and my priority is to make a really cool and reliable system. My main constraints have to do with weight and space. I will remove some weight from the boat (diesel engine and tank), but will add some too (electric motor, batteries, inverter…). I have done some math and given that I have some good margins to work with, I am not too worried about total weight. However, I do need to consider the positioning of those new components in the boat for weight and balance reasons.
Because the boat is docked to my house, my ultimate vision is to use it as the house's battery bank when it is docked to it. This way I can connect the boat to additional solar panels on the house, and by having a good inverter in the boat, it can power back some loads of the house.
Now that I have shared general context on this project, I wanted to share with you what I am considering and would welcome any suggestions/ comments/ ideas that you may have based on your own experience.
Batteries:
Connect in series 4x 12V EPOCH LiFePO4 batteries (460Ah) to build my 48v system.
12V 460Ah LiFePO4 Battery | Group 8D Size, IP67, Heated, Bluetooth & Victron Comms (epochbatteries.com)
If I were to build my own battery, I would likely double my prior system and have 2x48V batteries in parallel with 560AmpH capacity. Building my own gives me some flexibility on the shape of the overall battery, which helps with positioning on the boat. It is also the lightest option, but at the expense of effectively having less protection to the cells.
I have looked at 48V battery options like EG4 server rack or wall mounted (~200AmpH capacity). Those are essentially the same concept that I was going to build, but done professionally with all sorts of features included, s.a. breakers, fuses and communication ports. I could connect parallel some of these to get a bank of 400AmpH. Neither of these batteries are rated for marine use, but neither would be my DIY batteries…
Meanwhile, I came across these 12V EPOCH (460AmpH), I could connect 4 in series to have a 48V system (460AmpH). These are marine rated and seem to be robust and have all the main features that I value. My only concern at this point with this idea is that I will likely have to spread them a bit in terms of positioning in the boat. i.e. 2 in one place, and 2 in another place. That would mean that I would have to use some thick conductors to connect them and form my 48V bank. That doesn't sound as effective as having a battery bank that is made up of batteries that are all connected by shorth connections.
Detail: These EPOCH batteries have Victron Comms built in. I assume/hope that they can also connect to other components, like EG4 inverters, but I am still investigating that..
Inverter:
EG4 6000XP 48V 120/240V Split Phase | All-In-One Solar Inverter
EG4 6000XP Off-Grid Inverter | 8000W PV Input | 6000W Output | 480V VOC Input
I would like to have an all in one inverter, charger and MPPT controller. From my research so far, this seems to be the most interesting option. I just need to confirm that I can connect the communications from the EPOCH batteries to this inverter.
Secondary boat systems
I still haven't decided if I want to have a separate 12V bank like I had on my previous boat to power secondary systems. My rationale for having those 2 different banks in the past was:
Reliability - By having the 48v bank dedicated to the motor only, there would be no risk of something else draining the battery invertedly and leaving me without a way to "move".
Convenience - Powering the lights is easy, I could get a step down converter from 48V to 12V and power them. But those step down converters are very limited in how many Amps they can handle, and I would quickly have issues connecting things like a fridge or the music amplifiers with it. So having a 12V bank made all that easy.
I would love to hear any comments! Thank you
