It does not have all the cable ties yet as we need to disassemble it for transport to the boat. The thing is 250 pounds.
This battery is 24V and 10.5kWh. It has 8 Winston 400Ah cells (from Julia Yu) in series. Fuses are 400A for main leads and 30A for balancing leads. The shunt is from a Victron Smart BMV and has it’s own fuse position on the cell8 balance lead.
It was a lot of work; most of the aluminumwork was tapping threads in all the crossbars. If it doesn’t bother you I recommend using threaded rods with nuts on the outside instead of the square bar with bolts countersunk for a flush outside.
The big cables and all the heatshrink took some time as well but is unavoidable.
great work and neatly done. can you give us the working plans/schematics and dime3nsionms of the ready package? please.
Wow, 8 x 400Amp hour cells. I have 1, 400 AmpHr Lead Acid bank. So you have like 15 times my capacity in just that bank!
Do you really use ~7-8 KwHr a day? for what?
How do you charge it? That'd be a lot of solar panels!
Boat: Building a Max Cruise 44 hybrid electric cat
Posts: 3,198
Re: Jedi new battery finished
The cells are 3.2v each... So it adds up to 400ah at 24v. Still a good size house bank, but It's not 3200ah at 12v like you're thinking.
Matt
Quote:
Originally Posted by zstine
Wow, 8 x 400Amp hour cells. I have 1, 400 AmpHr Lead Acid bank. So you have like 15 times my capacity in just that bank!
Do you really use ~7-8 KwHr a day? for what?
How do you charge it? That'd be a lot of solar panels!
It does not have all the cable ties yet as we need to disassemble it for transport to the boat. The thing is 250 pounds.
Really nice work.
One comment though, as a wiring and cabling nazi lol, I try and stay away from wire ties. No matter how flush you try and cut them the ends are always sharp. Over time the can become embrittled from heat and exposure to things like fuel, oil, or other chemicals and vapors, and that also makes the sharp points and edges more likely to slice your arm or hand when you're working on or near it.
I always use wax lacing cord. Much neater in the end too.
Edit: Never mind, disregard, I see already discussed
My boat is the little sister of yours, Sundeer 56, with the two battery compartments in line over the keel. Each of my two traction batteries is about 600 amp/hrs, if untrustworthy memory serves, and about 500 lbs.?
How did you calculate for the difference from design weight, since our batteries are part of our ballast? Or is it not significant?
The new battery is around 265 pounds so significantly lighter, but still 265 pounds. We have sailed with this one compartment empty in bad weather in a bad place (Colombian Basin) and did not notice a difference so I’m not worried. The primary ballast the the lead hanging under it and I believe only that was used for calculations with anything added in the keel sump becoming part of the ballast but not required for stability specs.
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great work and neatly done. can you give us the working plans/schematics and dime3nsionms of the ready package? please.
On the schematic: I only put one balancing wire on the cell8 positive terminal and used links to attach two extra fuse positions to it. Same for one extra fuse position on the negative. Blue Sea Systems includes these links with the fuse blocks.
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This looks great! what is the approx cost of the cells themselves.
I bought these from Julia Yu (she’s on the forum) and Winston cells cost about $1 per Ah per cell.
Quote:
Originally Posted by nwn
It looks very nice. What is the BMS you are using?
I designed my own BMS with input from other forum members but did not find the time for testing it yet so that will happen as we go. I will start of with just a cell monitor and of-course a multimeter, bench power supply and load resistors.
Quote:
Originally Posted by flightlead404
Really nice work.
One comment though, as a wiring and cabling nazi lol, I try and stay away from wire ties. No matter how flush you try and cut them the ends are always sharp. Over time the can become embrittled from heat and exposure to things like fuel, oil, or other chemicals and vapors, and that also makes the sharp points and edges more likely to slice your arm or hand when you're working on or near it.
I always use wax lacing cord. Much neater in the end too.
Edit: Never mind, disregard, I see already discussed
I may do the waxed thread for the picture where possible we have switched to the new velcro cable ties.
__________________
“It’s a trap!” - Admiral Ackbar.
.........
One comment though, as a wiring and cabling nazi lol, I try and stay away from wire ties. No matter how flush you try and cut them the ends are always sharp. ...........
S/V Jedi will already know this but for other readers...
This cable tie nazi will only use 'ultra flush' cutters; not standard, not semi flush, not flush - only 'ultra flush'. I keep a pair for cable ties only, not used for any other purpose. Used with care, ultra flush cutters will not leave arm shredding sharp edges.
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I bought these from Julia Yu (she’s on the forum) and Winston cells cost about $1 per Ah per cell.
I designed my own BMS with input from other forum members but did not find the time for testing it yet so that will happen as we go. I will start of with just a cell monitor and of-course a multimeter, bench power supply and load resistors.
THXs for posting.
I also like the Winston 400 amp cells for big house banks.
Anything bigger and it gets also tricky with space.
Could You give more info on Your cell monitors and BMS ?
Certainly you have undertaken a major intellectual and physical task building your impressive battery bank. Your next stage is the other half of your significant project undertaking, creating a BMS, that protects all your charging assets as well as the batteries. from your comments I'm even more impressed you intend to build your own BMS? I understand why as most BMS commercial offerings fall short of protecting the boats full range of charging Assets.
Out of interest There is a NZ fellow you may compare notes with in building the other half of your your battery bank system. Being the indispensable working BMS brain! Eric Bretscher this is his area, purchased his custom build Ultrasonic antifouling unit he has an excellent web site will of lithium battery and BMS information on a download files. The information is helpful as well as impressive.
Nordkyn Design
Waiheke Island Auckland
NEW ZEALAND
Live to learn how your battery adventure turns out!!
Quote:
Originally Posted by s/v Jedi
So here it is all assembled and ready to go.
It does not have all the cable ties yet as we need to disassemble it for transport to the boat. The thing is 250 pounds.
This battery is 24V and 10.5kWh. It has 8 Winston 400Ah cells (from Julia Yu) in series. Fuses are 400A for main leads and 30A for balancing leads. The shunt is from a Victron Smart BMV and has it’s own fuse position on the cell8 balance lead.
It was a lot of work; most of the aluminum work was tapping threads in all the crossbars. If it doesn’t bother you I recommend using threaded rods with nuts on the outside instead of the square bar with bolts countersunk for a flush outside.
The big cables and all the heatshrink took some time as well but is unavoidable.
THXs for posting.
I also like the Winston 400 amp cells for big house banks.
Anything bigger and it gets also tricky with space.
Could You give more info on Your cell monitors and BMS ?
Certainly you have undertaken a major intellectual and physical task building your impressive battery bank. Your next stage is the other half of your significant project undertaking, creating a BMS, that protects all your charging assets as well as the batteries. from your comments I'm even more impressed you intend to build your own BMS? I understand why as most BMS commercial offerings fall short of protecting the boats full range of charging Assets.
Out of interest There is a NZ fellow you may compare notes with in building the other half of your your battery bank system. Being the indispensable working BMS brain! Eric Bretscher this is his area, purchased his custom build Ultrasonic antifouling unit he has an excellent web site will of lithium battery and BMS information on a download files. The information is helpful as well as impressive.
Nordkyn Design
Waiheke Island Auckland
NEW ZEALAND
Live to learn how your battery adventure turns out!!
I don’t think a BMS is that important for a house bank at all. Only when one needs to get every bit of capacity out of the bank it becomes critical. Example: my cells have a minimum discharge voltage of 2.5V and a maximum charge voltage of 4.0V. For 8s this comes down to 20V and 32V. If I first balance the cells and then cycle between 25V and 28V, how much out of balance need cells to go to get close to those min/max values? It will probably never happen, but a regular look at a cell monitor will make sure.
So my BMS is more of a hobby than necessity. Anyone who knows how to use a multimeter and bench power supply and with the discipline to regularly check a monitor can do without a BMS.
__________________
“It’s a trap!” - Admiral Ackbar.
Re: Jedi new battery finished
where possible we have switched to the new velcro cable ties.
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