Battery Setup for Hybrid solution

[Nidnoi_V]

Hi All

all batteries are based on LiFePO4

I¨m seeking your Advise; I’m about to convert a Catamaran to an Electric /Hybrid. With this setup, I will be able to use my motor between 4-5 hours depending on Seastake, etc. or pure electric, which means I can save roughly 20 Liters or 17 KG per usage
However, I will also have things running on 12/24, which my Idea is to make a Secondary battery bank on 24V, running fan, light, navigation, etc.
For A/C appliance and propulsion, I would have 28Kwh at 48V DC

1. Solution 1

3 Battery banks

a. 48V Battery bank running with 600 AMP or 28. KWh weight 250KG
b. 48V Battery bank running with 600 AMP or 28. KWh weight 250KG
c. 24V Battery bank running with 1200 AMP or 14.2 KWh weight 165KG
Total Weight 665 KG

2. Solution 2

2 Battery banks

a. 48V Battery bank running with 750 AMP or 35.5 KWh weight 312,5KG
b. 48V Battery bank running with 750 AMP or 35.5 KWh weight 312,5KG
Total Weight 625 KG

I¨m aware I will need DC/DC converters from either 48 to 24/12v or 24/12V
My concern is here how much AMP hours will I lose when downgrading to 24/12 V
For Charging the batteries, the following installation is made 2800 watt Solar power plus also regen from the Electric Engines when sailing for sail

[GoneDiving]

Do you have your batteries yet?

Aliexpress are having a sale on 11.11. I just bought 43kwh of LiFePo4s for USD6k. My configuration will be 840ah @ 48v but they can be assembled in what ever configuration you want.

Good luck

[Nidnoi_V]

Originally Posted by GoneDiving

Do you have your batteries yet?

Aliexpress are having a sale on 11.11. I just bought 43kwh of LiFePo4s for USD6k. My configuration will be 840ah @ 48v but they can be assembled in what ever configuration you want.

Good luck

I haven't order the batteries yet however i have chosen the Battery Supplier which will be between 3 suppliers mgenergysystem, ER Power Buddy or Valence

and Thanks going to be a nice Winter task taking out old diesel engines installing electric motors still thinking on which brand either OceanVolt or kraeutler seems like kraeutler are more efficient

[tkeithlu]

"For Charging the batteries, the following installation is made 2800 watt Solar power plus also regen from the Electric Engines when sailing for sail"

Relying on solar and regeneration by running an impeller while sailing is suspect. The 2800 watts is only there at noon on a sunny day in the tropics. The impeller is not free lunch; knot hours lost to the impeller cannot exceed knot hours gained from the batteries thereby charged. This is a point at which you'll have a whopping inefficiency.

Perhaps back up for a moment and think about making the system flat battery proof. Perhaps include a genset that can propel the boat at get-home speed without depending on there being anything in the batteries.

[Nidnoi_V]

Originally Posted by tkeithlu

"For Charging the batteries, the following installation is made 2800 watt Solar power plus also regen from the Electric Engines when sailing for sail"

Relying on solar and regeneration by running an impeller while sailing is suspect. The 2800 watts is only there at noon on a sunny day in the tropics. The impeller is not free lunch; knot hours lost to the impeller cannot exceed knot hours gained from the batteries thereby charged. This is a point at which you'll have a whopping inefficiency.

Perhaps back up for a moment and think about making the system flat battery proof. Perhaps include a genset that can propel the boat at get-home speed without depending on there being anything in the batteries.

i will have genset system setup so that part is covered my question is purely regarding the Battery banks set up

but to Answer your question
Invertor Model
victronenergy 48/10000/200-100/100 48V
victronenergy 48/10000/200-100/100 48V
victronenergy 24/5000/120-100/100 24V

Genset /Generator Model Output
Fisher Panda AGT 13000 PMS 13,1 KW
Whisperpower M-GV 15 MARINE 12 KW

[GoneDiving]

Originally Posted by Nidnoi_V

i will have genset system setup so that part is covered my question is purely regarding the Battery banks set up

but to Answer your question
Invertor Model
victronenergy 48/10000/200-100/100 48V
victronenergy 48/10000/200-100/100 48V
victronenergy 24/5000/120-100/100 24V

Genset /Generator Model Output
Fisher Panda AGT 13000 PMS 13,1 KW
Whisperpower M-GV 15 MARINE 12 KW

What problem are you actually trying to solve?

From your lists above I can see $100k easily disappearing to save 20 litres of diesel per day.

[Nidnoi_V]

Originally Posted by GoneDiving

What problem are you actually trying to solve?

From your lists above I can see $100k easily disappearing to save 20 litres of diesel per day.

how i should design the battery pack

[GoneDiving]

Originally Posted by Nidnoi_V

how i should design the battery pack

Hate to be a smart a$s but if you have to ask that then this may not be a diy job to take on as your first project.

Broadly speaking 48v is 16s for lifepo4. Keep adding cells in parallel until you get the current and capacity capability you are chasing. Wiring and battery connectors need to be sized appropriately.

Good luck but be careful.

[Nidnoi_V]

so i should not ask for adviser on what is the best way to set up battery banks?

even I have the knowledge and know-how to set it up and it will be more than

I have used my engines and Generator for roughly 1600 hours over a year and between 2-5 hours per time so I should be able to save much more on the Diesel over a period of 10-12 years

[mcarthur]

I thought that the DC-DC converters are generally maxed at about 80-85% efficient, so you'll lose about 15-20% in the transfer. But have a talk with Safiery* over how they are integrating a buckboost conversion, which may or may not be better for you.

* I have no connection with Safiery, in Australia, other than as a future potential customer.

[mcarthur]

PS. we're in planning for conversion of our 50' powercat to parallel hybrid and have a draft electrical plan considering the changes between 48V (solar input, alternator input and main/propulsion battery), 240v (shore input and use), and 12v use...

[Sailing Ohm]

Originally Posted by mcarthur

I thought that the DC-DC converters are generally maxed at about 80-85% efficient, so you'll lose about 15-20% in the transfer. But have a talk with Safiery* over how they are integrating a buckboost conversion, which may or may not be better for you.

* I have no connection with Safiery, in Australia, other than as a future potential customer.

I’m designed an electric sailboat and I got a DC to DC converter used for electric cars. It said it had a 95% efficiency

[Sailing Ohm]

My advice is to get the highest voltage battery bank you can. Your solar mppt controller as well as your electric motor and it’s controller will likely want the highest voltage possible. Our motors controller can go from a nominal of 48V to 96V so most are flexible and just need to be programmed with a CANBus while our solar mppt can handle up to 150VDC. Higher voltage would mean more efficiency for your mppt and more power from the electric motor. Not to mention the savings in wire (If you want to get crazy you can even rewire your windlass with a new electric motor that handles the higher voltage, the cable savings here are huge!)

I run our system at 60VDC (it was the most battery we could fit) then drop it down to 12V right before the DC panel with a dc-dc designed for electric cars (worked great for 3 years now)

[Nidnoi_V]

Originally Posted by Sailing Ohm

I’m designed an electric sailboat and I got a DC to DC converter used for electric cars. It said it had a 95% efficiency

could you send the
model and Brand as well
and Thank you for your feedback

[Nidnoi_V]

Originally Posted by mcarthur

PS. we're in planning for conversion of our 50' powercat to parallel hybrid and have a draft electrical plan considering the changes between 48V (solar input, alternator input and main/propulsion battery), 240v (shore input and use), and 12v use...

Could you share your Draft please or link it somewhere really keen to know more about this