nlspace wrote: ↑
Wed Dec 11, 2019 7:09 am
Sniffing CAN buss data is not the same as reverse engineering the LBC and the VCM. i've seen no evidence that any level of reverse engineering has been done for the Leaf other than some inverter boards on the diy forum.
Reverse engineering means you have the circuit schematics and the controller firmware, and can troubleshoot, repair or modify either of these as needed for your purposes.
Ask user coulomb about this, he is a world class expert.
Turbo3 did some analysis of the LBC (viewtopic.php?f=8&t=17470
). I was thinking about this last night and if Fenix is going to be installing their own replacement pack, they'll either need to have reverse engineered the LBC enough to come up with their own LBC to spoof all the data and responses the VCM expects.
Or, they'll need to use an existing LBC but have something else the spoofs all the responses and voltages the LBC expects. This is in addition to managing their own cells.
nlspace wrote: ↑
Tue Dec 10, 2019 8:05 am
What is the level of knowledge, skills, abilities and experience of Fenix Power with respect to the design, management and control of packs built up of small cylindrical cells in parallel?
Who is going to design and build the circuit boards necessary for monitoring the cells and control of the pack?
And how is this new pack going to be integrated with the current operating system of the Leaf?
Yep on all of this. Good question.
As has already been mentioned, there are all sorts of potential safety concerns just from the cells sitting idle, charging and discharging, esp. overcharge conditions, cell failure, overheating, etc. What if the pack quits or the software/firmware running on their BMS gets into a bad state while charging or while the car's being driven?
GM has a massive battery lab: https://media.gm.com/media/us/en/gm/new ... y-lab.html
and I'm sure lots of engineers who know what they're doing. What sort of testing is Fenix going to be able to do beyond simple static tests and some tests involving driving and charging?
I could see major liability issues coming up if there were an accident due to pack or software failure or li-ion fire or thermal runaway. And, there are liability concerns if a Leaf gets into a severe accident with one of these packs.
How does the supposed thermal management integrate with the existing AC system and radiator?
I'm concerned that the management at Fenix is almost like a bunch of Kickstarter guys trying to come up with a hardware device but have no EE or embedded systems knowledge nor any knowledge of manufacturing or sufficient knowledge of bringing hardware from 0 to finished product. Basically, "what? we need to test for this? We need to pay someone to do that? Who knew it cost this much for tooling for molds?" If they had a proven track record of designing battery packs and BMSes for automotive applications along w/extensive knowledge of CAN (for example), then I'd feel more comfortable.
They seem to have ideas but given the lack of demonstrated progress (e.g. demos), I question their ability to execute and have something even shippable to paying customers that's safe by the end of 2020. I wonder if it can happen by the end of 2021. They need to train other installers and at least write documentation on how to troubleshoot and effect repairs if customers hit problems. This has to happen while someone manages them swapping worn Leaf packs with genuine Nissan ones in better shape.
The task isn't impossible but there's the question of the cost to achieve it, funding, expertise (if it's not in house now, they need to hire and pay them), timeframe, whether the business model is sustainable and whether there's sufficient real demand. Will they be done so late that there won't be sufficient demand? We've seen how little old degraded Leafs are worth and the march forward in EV evolution.