Merged LiFeYPO4 1000Ah Winston prismatic cells and all electric galley...

[newhaul]

Originally Posted by aybabtme

Alright I know just a few weeks ago I was lambasting the unecessity of using raw cells in our modern times with the abundance of high quality and cheap commercial packs. But alas, reality struck me and the odd shape of the locker where I can store the batteries is forcing me down the path of a custom pack made with raw cells.

* * *

Here's the requirement brief:

• 35ft lightweight catamaran (Seawind 1000 XL2)
• Rated for max 2x10kW engines, so design for 20kW continuous discharge (although will be less than that in reality).
• Aim for 1h range at full power (20kWh).
• Obviously 48V nominal for this power requirement. I don't want to go higher than 60V.
• Price is a lesser concern, since it's overall not a big differentiator in the overall project.
• Delivery to California (SF or LA).
• Available volume is two compartments of dimensions 890mm (length) 250mm (width) 41mm (height).
• Weight is a concern, so aluminum encased cells it is.

Right now the contenders are:

• CATL 302Ah in 2P16S: 185Wh/kg, 167kg, 30.9kWh
• CALB L173F230B in 2P16S: 175Wh/kg, 134.4kg, 23.6kWh
• Fortune 205Ah in 2P16S: 156Wh/kg, 134.4kg, 20.9kWh

The Fortune could seem a clear loser here, but they gain extra point in my book for being so easy to assemble and work with.

Here's my notes so far (see "Mothership: LFP cells"). The BMS is a Rec Q 16S. Busbars and distribution is Victron's Lynx setup with Cerbo GX and Multiplus II for main charge source.

Actual engines will probably be ePropulsion Navy 6.0, although their long shaft variant is a bit too short. Current engines are gas Yamaha 9.9 outboards with extra-long shafts (25"). I'll figure out some story for "range extension" later. We have gasoline tanks onboard so the easy way is to used Honda EU2200... but I don't like the smell of gasoline. And yes, it's unclear whether this is all a good idea or not, but I want to try it out so
* * *

I guess there should be a question: do you know of any cell I should evaluate here that's not in my spreadsheet?

Have you considered 48 volt server rack battery packs? Something like this https://www.amazon.com/DJLBERMPW-Lit...06658311&psc=1
There are a lot of them out to choose from

[aybabtme]

I did, I was referring to that in saying that I'm doing a 180º turn from my own prior recommendation :P. The server rack packs don't fit by a mere inch, and if they did, I couldn't fit enough of them to supply the power requirement of 20kW continuous discharge. Unfortunately, the raw cell approach is the only way to get the high power rating (using BMS controlled contactor instead of MOSFETs) and the volumetric density. On top of it, these server racks don't do so well in weight density either, at about 100-110 Wh/kg, whereas a raw cell pack made of CATL or CALB pack can reach 175-185 Wh/kg.

[newhaul]

Originally Posted by aybabtme

I did, I was referring to that in saying that I'm doing a 180º turn from my own prior recommendation :P. The server rack packs don't fit by a mere inch, and if they did, I couldn't fit enough of them to supply the power requirement of 20kW continuous discharge. Unfortunately, the raw cell approach is the only way to get the high power rating (using BMS controlled contactor instead of MOSFETs) and the volumetric density. On top of it, these server racks don't do so well in weight density either, at about 100-110 Wh/kg, whereas a raw cell pack made of CATL or CALB pack can reach 175-185 Wh/kg.

Ok good you did your homework welcome to the dark side

[CaptainRivet]

Originally Posted by aybabtme

Alright I know just a few weeks ago I was lambasting the unecessity of using raw cells in our modern times with the abundance of high quality and cheap commercial packs. But alas, reality struck me and the odd shape of the locker where I can store the batteries is forcing me down the path of a custom pack made with raw cells.

* * *

Here's the requirement brief:

• 35ft lightweight catamaran (Seawind 1000 XL2)
• Rated for max 2x10kW engines, so design for 20kW continuous discharge (although will be less than that in reality).
• Aim for 1h range at full power (20kWh).
• Obviously 48V nominal for this power requirement. I don't want to go higher than 60V.
• Price is a lesser concern, since it's overall not a big differentiator in the overall project.
• Delivery to California (SF or LA).
• Available volume is two compartments of dimensions 890mm (length) 250mm (width) 41mm (height).
• Weight is a concern, so aluminum encased cells it is.

Right now the contenders are:

• CATL 302Ah in 2P16S: 185Wh/kg, 167kg, 30.9kWh
• CALB L173F230B in 2P16S: 175Wh/kg, 134.4kg, 23.6kWh
• Fortune 205Ah in 2P16S: 156Wh/kg, 134.4kg, 20.9kWh

The Fortune could seem a clear loser here, but they gain extra point in my book for being so easy to assemble and work with.

Here's my notes so far (see "Mothership: LFP cells"). The BMS is a Rec Q 16S. Busbars and distribution is Victron's Lynx setup with Cerbo GX and Multiplus II for main charge source.

Actual engines will probably be ePropulsion Navy 6.0, although their long shaft variant is a bit too short. Current engines are gas Yamaha 9.9 outboards with extra-long shafts (25"). I'll figure out some story for "range extension" later. We have gasoline tanks onboard so the easy way is to used Honda EU2200... but I don't like the smell of gasoline. And yes, it's unclear whether this is all a good idea or not, but I want to try it out so
* * *
I guess there should be a question: do you know of any cell I should evaluate here that's not in my spreadsheet?

Open a new topic thread please, this has nothing to do with any of the topics discussed here. That's a high C-rate propulsion bank which is a totally different cup of tea then a low C rate house bank.
They are many cells you missed but you have many other troubles to sort out first.
And replacing lightweight 9.9hp outboards with epropulsion adds significant amount of weight, all in the back as cable runs must be as short as possible so close to motors. Start up surge is 3-10x continuous C with a e-motor

[aybabtme]

good call, here's the thread https://www.cruisersforum.com/forums...ml#post3652307

[Simi 60]

Originally Posted by newhaul

Ok good you did your homework welcome to the dark side

Wouldn't it be the light side?

[newhaul]

Originally Posted by Simi 60

Wouldn't it be the light side?

Depends on your view of DIY vs Drop in lifepo4 banks. Drop ins are more mainstream now that when we started with lfp . All there was for us was build our own aka the dark side.

[CaptainRivet]

Originally Posted by newhaul

Depends on your view of DIY vs Drop in lifepo4 banks. Drop ins are more mainstream now that when we started with lfp . All there was for us was build our own aka the dark side.

Let's agree it's the right side

[s/v Jedi]

Originally Posted by CaptainRivet

Let's agree it's the right side

Being a Jedi myself, I can confirm building from prismatic cells is definitely the light side

[CaptainRivet]

Originally Posted by s/v Jedi

Being a Jedi myself, I can confirm building from prismatic cells is definitely the light side

Definitely the light side too if you make a mistake when connecting all the cells
Most common drop your unisolated wrench or screwdriver or mix up polarity eg Lishen and EVE the black pole is plus

[s/v Jedi]

Originally Posted by CaptainRivet

Definitely the light side too if you make a mistake when connecting all the cells
Most common drop your unisolated wrench or screwdriver or mix up polarity eg Lishen and EVE the black pole is plus

Their terminals are so small, they act as the fuse

[newhaul]

Originally Posted by CaptainRivet

Definitely the light side too if you make a mistake when connecting all the cells
Most common drop your unisolated wrench or screwdriver or mix up polarity eg Lishen and EVE the black pole is plus

Simple answer. Applies to most things ATD.
Attention to detail.

[Simi 60]

Originally Posted by CaptainRivet

Most common drop your unisolated wrench or screwdriver or mix up polarity eg Lishen and EVE the black pole is plus:whistling:

Must admit I never even noticed that the poles were different colours
It was the miniscule + - symbols that were an issue for me

White pen sorted that

[newhaul]

Originally Posted by Simi 60

Must admit I never even noticed that the poles were different colours
It was the miniscule + - symbols that were an issue for me

White pen sorted that

I use white nail polish yes nail polish lasts forever and highly visible and available in about any color you want

[s/v Jedi]

On the Winston the terminals are different (copper vs aluminum) but when the busbars are mounted, you can’t see that anymore and have the red marker as well as injection molded symbols to identify polarity.