I am in New Plymouth and have built a number of battery packs for ebikes and have built my own for my foil. Have a reliable supplier for 18650 cells but it is the freight that is really high as they are dangerous goods. Have not worried about a bms on thefoil as they can be unreliable but have seen a new model come up that looks promising and will use on next battery build. It can also be programmed by your phone.
Do you have surplus cells or are you looking at getting some more in soon? Would be interested in splitting shipping costs etc. What cells are you using?
I wasn’t going to use a BMS either, as I was planning to build 2x 6S packs to allow charging on a balance charger and then I monitor each cell with my arduino and stop is any issues with a cell. That BMS looks pretty sweet but it is huge!
For my ebike batteries I have always used a bms but my foil has 2x6s and use a balance charger like you are thinking of using. The cell I use are ncr18650pf Panasonic. Am looking at getting some soon will let you know when I do.
I was just looking at Hobbyking Multistar batteries. What happened to their pricing? I bought 4s 10Ah batteries for $25 two years ago. They now have the same batteries for $90 on sale at half price. That makes its super expensive to go with batteries that are going to have issues with charging and such. Better to go cylindrical cells or buy ebike batteries.
Our board has a 36v 40Ah pack. To get a similar size pack from Hobbyking would be 8*$90 or $720. Much better idea to get some longer lasting batteries.