If I weren’t 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!
It would be good to take a look and try to learn. it is just a waste if you can’t 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!
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!
Yeah that’s 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$/pcs (bms) with the quantity they are buying. So overall it sure force respect but you still shouldn’t look at the prices for low quantity on a project of this scale.
They might be at 1000$ cost price for the total battery pack in the end…
I understood that the battery failed because the battery voltage remained present at the output, is that correct? And we’re 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.
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). I’m just not sure if Victron makes them or buys them elsewhere…
Super helpful thread! Without going too off topic, my goal is simple: I want a battery with 50% of the weight. @foilmore given your better understanding of the setup, can you comment on potentially removing some of the cells with a view to having a shorter run time but lower weight?
Im guessing the power would not be high enough but really curious to hear peoples thoughts.
In my opinion, the weight of the lift foils is the biggest disadvantage, especially for wave riding.
I am glad this helped someone already. If you are okay spending 5-15 hours and risking $3,500 going up in smoke it seems maybe doable, but I can’t say for sure, because I am not going to be pulling apart the welded zinc and cells since they all look healthy. I don’t recommend it.
Here are some thoughts:
The case itself is surprisingly heavy without the batteries in it. I will weigh it to see, but it is one thick piece of plastic!
Due to how it was manufactured, it would be a major undertaking by an experienced person to pull half of the cans out. It looks possible since I am not seeing the batteries themselves epoxied together (despite what was shown in the B-roll in the video) and they are separated nicely in the case.
You would only be able to drop half of the cells which is just under 5kg from the pack weight (only about 1/3 of the total) for this effort. The 30Q cells are rated for 15amp discharge and 25amp burst, so running them at 7p at full throttle you are approaching their limit and they are going to heat up and have diminished life. You are going to need to be pinning the throttle at times to scramble out of the whitewash, right?
It seems Lift made it very difficult for you to build your own custom weight-weenie as you would have to reverse engineer the BMS <-> ESC CAN 2.0B data connection to make the ESC work.
I think the time and money would be best spent doing the following:
Bypass the Lift ESC and use your own custom battery, VESC, and remote. Or maybe just build a board setup for wave riding and swap over your Lift motor, LOL. In essence, Lift made it pretty dang hard to avoid purchasing their $3,500 batteries in the future for owners.
