I am strongly considering electric motors for my auxiliary power on my sailboat. I am planning to do some extended cruising, some of which will require motoring only, and not happy with my gas outboard. The motors are 48 volts / 4KW each and I plan to install two motors with a dedicated battery system of approximately 9216 WH each. I also have need of a house power at 12 volts. I plan to budget the house bank in two separate banks, both 4608 WH each. I currently have a 12 volt / 400 watt wind generator and approximately 100 watts of solar and about 6 KWH of SLA batteries, as well as a 2K gas generator. I plan to significantly increase my wind and solar capacity for this project. The total of nearly 20KWH should give me around 8 hours of cruise time at half throttle at 4-5 Kts, based upon vendor information.
I plan to add an additional 12v/400w wind generator for a total of 800w of wind generation at ~12 volts charging capability. I have room for two 160w solar panels and plan a modification, in order to install 4 total solar panels. This would result in 1.6KW of wind and solar generators. This also does not include the motors themselves, which regenerate while under sail or at anchor in currents.
My inclination is to setup all four battery systems the same with 3.2v LiFePO4 180AH batteries and tailor the all charging systems at 12 volts. My primary reason for doing this is shading. In order to setup solar panels for 48 volt charging I would need sun on port and starboard, which is only occasional. For 12 volts, I should get more consistent charging. I would run 12 volt to 48 volt step up regulators, one for each bank. (Initially, I would use the SLA batteries, which are currently setup in port and starboard banks until they became problematic.) Genasun makes a "boost" regulator that is even customizable, which may be what I get. The 56.8v Lithium is pushing the envelope for me, but also acceptable. The Genasun manual is located at
https://cdn.shopify.com/s/files/1/00...87046331177433
I would hope that the boost regulator is precise enough to keep me at or below 95%, and I would prefer 90%. If not, I will add a regulator.
The BMS, below, should include LVD and HVD, but I am not too concerned about constant voltage. There is much hooplah about float charging LiFePO4, but I cannot buy into it. I agree that whenever you have different tensions, that there will be pressure to equalize, but this is the same with batteries in parallel because there is no perfection when it comes to batteries. The logic that I see is moderation, as with anything else. Longevity is probably my most important criteria. By keeping the systems at, or below 90% and at "float", I suspect that the tension is no worse than a parallel battery. That is my uneducated, in this arena, OPINION. I do have a BSEE, so I am not totally useless when counting electrons.
The motors being evaluated are E-Tech 4POD and can be found at
https://starboats.eu/electric-drives...h-pod-engines/
I plan to use the outboard version in order to also use the engine as a tender motor, which will require another battery pack, engine controller, and throttle control.
I plan on using LiFePO4 prismatic batteries for everything. I am currently looking at
which are CALB prismatic 180AH batteries. I would need 16 each (16S) of the propulsion systems and eight each (2P4S) for the house banks. I really won’t know until I get the first 16 in, but I plan to assemble them in groups of 4, or 12 volts, compression packs. This makes them more portable for me. I looked at the LiFePO4 pouches and they just do not appear durable enough for the environment that they will be in. I may "toy" with the 50AH dinghy pack with the pouches. The second, but significant part of this system is the battery management system.
Since I will need a BMS for each system and plan to have five systems including a portable 50AH pack for the dinghy, I cannot rationalize $600 or $800 for each BMS. I found this at
https://energusps.com/shop/product/t...6-150a-750a-36
which does not include accessories, such as sensors and Bluetooth. I would like to have individual cell monitoring, balancing, and control, but that is not happening on my budget. I do plan on HVD and LVD on the four major systems and probably temperature sensors.
I just ordered a prepackaged LiFePO4 battery last week for another application and evaluation from a reputable lithium distributor and their charger will both overcharge and float charge, with no instructions to do otherwise. I was very disappointed. It tells me that distributors either don't know or don't care how long your batteries last. Most only have a two-year warranty, which almost all LiFePO4 batteries should meet, so it is in their best interest for you to treat your batteries poorly. That is why I am here.
Thanks for making to the end of my lengthy post and I thank you, in advance, for your opinions and advice.
Regards,
Jeff
I plan to add an additional 12v/400w wind generator for a total of 800w of wind generation at ~12 volts charging capability. I have room for two 160w solar panels and plan a modification, in order to install 4 total solar panels. This would result in 1.6KW of wind and solar generators. This also does not include the motors themselves, which regenerate while under sail or at anchor in currents.
My inclination is to setup all four battery systems the same with 3.2v LiFePO4 180AH batteries and tailor the all charging systems at 12 volts. My primary reason for doing this is shading. In order to setup solar panels for 48 volt charging I would need sun on port and starboard, which is only occasional. For 12 volts, I should get more consistent charging. I would run 12 volt to 48 volt step up regulators, one for each bank. (Initially, I would use the SLA batteries, which are currently setup in port and starboard banks until they became problematic.) Genasun makes a "boost" regulator that is even customizable, which may be what I get. The 56.8v Lithium is pushing the envelope for me, but also acceptable. The Genasun manual is located at
https://cdn.shopify.com/s/files/1/00...87046331177433
I would hope that the boost regulator is precise enough to keep me at or below 95%, and I would prefer 90%. If not, I will add a regulator.
The BMS, below, should include LVD and HVD, but I am not too concerned about constant voltage. There is much hooplah about float charging LiFePO4, but I cannot buy into it. I agree that whenever you have different tensions, that there will be pressure to equalize, but this is the same with batteries in parallel because there is no perfection when it comes to batteries. The logic that I see is moderation, as with anything else. Longevity is probably my most important criteria. By keeping the systems at, or below 90% and at "float", I suspect that the tension is no worse than a parallel battery. That is my uneducated, in this arena, OPINION. I do have a BSEE, so I am not totally useless when counting electrons.
The motors being evaluated are E-Tech 4POD and can be found at
https://starboats.eu/electric-drives...h-pod-engines/
I plan to use the outboard version in order to also use the engine as a tender motor, which will require another battery pack, engine controller, and throttle control.
I plan on using LiFePO4 prismatic batteries for everything. I am currently looking at
https://www.dhgate.com/product/prismatic-rechargeable-lithium-lifepo4-battery/469834156.html
which are CALB prismatic 180AH batteries. I would need 16 each (16S) of the propulsion systems and eight each (2P4S) for the house banks. I really won’t know until I get the first 16 in, but I plan to assemble them in groups of 4, or 12 volts, compression packs. This makes them more portable for me. I looked at the LiFePO4 pouches and they just do not appear durable enough for the environment that they will be in. I may "toy" with the 50AH dinghy pack with the pouches. The second, but significant part of this system is the battery management system.
Since I will need a BMS for each system and plan to have five systems including a portable 50AH pack for the dinghy, I cannot rationalize $600 or $800 for each BMS. I found this at
https://energusps.com/shop/product/t...6-150a-750a-36
which does not include accessories, such as sensors and Bluetooth. I would like to have individual cell monitoring, balancing, and control, but that is not happening on my budget. I do plan on HVD and LVD on the four major systems and probably temperature sensors.
I just ordered a prepackaged LiFePO4 battery last week for another application and evaluation from a reputable lithium distributor and their charger will both overcharge and float charge, with no instructions to do otherwise. I was very disappointed. It tells me that distributors either don't know or don't care how long your batteries last. Most only have a two-year warranty, which almost all LiFePO4 batteries should meet, so it is in their best interest for you to treat your batteries poorly. That is why I am here.
Thanks for making to the end of my lengthy post and I thank you, in advance, for your opinions and advice.
Regards,
Jeff
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