Getting the battery out required some judicious use of unconventional electronics tools to help the epoxy decide to let go.
Inside case around handle:
Bottom:
Quarter view of the ribbon cables and board:
One sexy looking BMS board. Clear labels all over it too!
Quick observations:
There are two thermistors on top and two on the bottom of the pack. *
There are test points all over the place!!!
Upon closer inspection of the tiny ribbon cables, they are not using nearly as many pinouts as I thought. It does not appear to be wired to individual cells at all now that i am looking at it in the light⌠pretty standard setup. No crazy 196 cell matrix stuff as I presumed when it was in the dark before.
The temp signals are sent into the ribbon cable with the parallel group voltage sensor wires.
The thermistor port on the front of the board is not being used.
It is one of one the prettiest mass produced battery systems I have seen. I feel kind of bad tearing all of this apart and am tempted to try to spend more time to learn how to connect and hack into the BMS via the CAN bus, but it is just not worth my time. I am going to replace this work of art with a cheap one with bluetooth, LOL.
*edit #2: I was just tracing things and realized I missed 2 thermistors cables hiding in the epoxy in my haste! There are actually 8 temp sensors total between the 4 cables.
I have designed couple of BMS for work and one for my efoil. This BMS clearly is not the best design. Lots of flexes and wiring which means more point of failure plus very expensive labor. No wonder why they sell it for $3500. Which market price for 14214p performance pack is around $1500. Other issue I see is the contactor for this application. I am goingto stop complaining and give them credit to do lots of testing to be able to get all the certifications passed.
just be careful if you buy cheap bms it will not work with lift Delta -Q charger. My BMS works wit the same Delta-Q charger. These charger comes with 2 falvor of CAN communication, CANopen or J1939. My BMS works with CANopen flavor. I wish I was able to manufacture the BMS for cheap for DIY community so they can buy Delta-Q charger and get the all great benefits of both.
I will use a repurposed/retuned kingpan charger I have sitting around from ebike projects.
http://www.kingpan.cn/cpzx/list_77.aspx?lcid=11
If I werenât going with a BMS I would plan to use my iCharger 3010b and balance charge half of the battery at a time.
The new BMS I will use for charging/balancing will most likely be the 20amp version of this one:
I will be able to connect directly with it via BLE using my phone to program it and link to the metr pro via BLE for monitoring along with all my VESC info in one place.
@samisin - Do you want me to send you this BMS board so you can play with it? You know far, far more about these things than I do!
Does anyone know if this main power connector is an off the shelf part or is it a proprietary Lithos creation?
It would be good to take a look and try to learn. it is just a waste if you canât use the charger. I am wondering if you even can use a custom battery with lift board. when you connect the lift battery do you have to connect the CAN port the motor controller with some sort of a cable or no? Wondering if motor controller communicates with battery
I do not own a Lift efoil, but when I rented one you had to plug in the main power cables and the ESC needed to also be connected to the 6 pin CAN data connector on the board for it to run. Send me a PM and we can figure out a way to get you this BMS board!
This has been a hunt from day one ! Not much luck so far. Probably custom. Do you see any manufacturer symbol or logo inside the case ?
The male and female metal connectors are manufactured by Odu, a German company.
Do you know the wattage of the bleeding resistor? If you can take a good closed up photo where the resistors would help⌠I think there should be (12-14) 22ohm single/parallel resistors on on each slave board⌠It maybe totally different configuration⌠From the photo, it seem more likely they are using Active balancing!
thanks
Yeah thatâs exactly what I thought ! This stuff is pretty pricy if you look at 1 piece but I bet Lithos can get them for less than 300$/pcs (bms) with the quantity they are buying. So overall it sure force respect but you still shouldnât look at the prices for low quantity on a project of this scale.
They might be at 1000$ cost price for the total battery pack in the endâŚ
It is custom made, I am 100% sure of it because of the material they are using (PA66 + 30% GF).
Found the fuse they are using. Itâs a Littlefuse Mega 300A :
Thats a 32V fuse.
You looking for this one:
I understood that the battery failed because the battery voltage remained present at the output, is that correct? And weâre you able to determine whether the relay was stuck closed or that maybe the precharge remained enabled?
Yeah, that makes perfect sense it is the exact same material as the case and seems to be plastic welded in like the rest of the seams. I will try to make a 3d printed waterproof plug if I can get a hold of those female connectors.
I am still unsure what was broken. There are no obvious failures. The relay would have been stuck open. Pack read 0v at the exterior terminals.
Last remaining step, I still need to cut open the part of the case that hides the relay so I can extract and test it.
The fuse is from this series:
https://www.digikey.com/en/products/detail/littelfuse-inc/142.5631.6202/2515909
I use 250A version. It meets all the requirements for our application and has all the regulatory certifications
Nope, wrong series. Lift/Lithos use a fuse from the BF2 series. The one I posted is the exact fuse they use (look at the direction of the 300A and BF2 writing on the fuse). Iâm just not sure if Victron makes them or buys them elsewhereâŚ
It does seem to be this one:
The Lithos one even has the BF2 model number on it in the same place.
The back says:
P 58v
300
A1919
@samisin is correct though. The BF1 is the little brother to this one and https://www.littelfuse.com/ is the manufacturer.
