Cell harvesting has been going on for years but I need to plan for next step, actually putting them into packs. Aiming for 50 kWh in a 14s 48 V system.
I see a lot of open packs on shelves. I'm thinking about fire-proofing and ease of expanding. Filling a 2 HE 19" box with 20x18 cells would look professional but adding more cells to the system (14s for 48 V) would take 20x18x14 = 5040 more cells for each step. Cost of boxes and connectors would certainly add up too.
I made two drawings, packing inside a rack box and series-parallell connection if boxes to make 14s3p (packs, not cells). I didn't find an obvious way to make a Y-split with SurLok connectors, so I just put two on each box with internal busbar. It would take more cabling to make a junction box for each in a separate 1HE box but would be far more flexible.
Does my idea that packing cells into a steel box, preferably without ventilation and sealed, would limit the spread of a fire in case of an internal short in a cell somewhere hold any merit?
Does anyone have any similar system or have looked into it? Would you have done it differently in hindsight?
Would it be better to build each box for 48 V with internal BMS and balancing, same as Pylon? Current would certainly be lower but balancing would also take more effort (more BMSes).
I see a lot of open packs on shelves. I'm thinking about fire-proofing and ease of expanding. Filling a 2 HE 19" box with 20x18 cells would look professional but adding more cells to the system (14s for 48 V) would take 20x18x14 = 5040 more cells for each step. Cost of boxes and connectors would certainly add up too.
I made two drawings, packing inside a rack box and series-parallell connection if boxes to make 14s3p (packs, not cells). I didn't find an obvious way to make a Y-split with SurLok connectors, so I just put two on each box with internal busbar. It would take more cabling to make a junction box for each in a separate 1HE box but would be far more flexible.
Does my idea that packing cells into a steel box, preferably without ventilation and sealed, would limit the spread of a fire in case of an internal short in a cell somewhere hold any merit?
Does anyone have any similar system or have looked into it? Would you have done it differently in hindsight?
Would it be better to build each box for 48 V with internal BMS and balancing, same as Pylon? Current would certainly be lower but balancing would also take more effort (more BMSes).