New work TBD (ToBeDone)

OK, so it is almost a year since I "completed" the bike project, rode it around a few times, and unveiled it at work. I since accepted that my BMS that took me hours and hours of soldering to complete, was no good. Not because it didn't work, but because I didn't have a good way to test it. The BMS is the most important part of the machine. It protects the cells, and if one burns, we are looking at several hours of work and at least $100 to fix it.

To remedy the situation I coughed up $600 to buy a BMS from ElectricMotorsport. This way, I can take parts back to them if anything isn't working correctly. Their BMS also has a datalogger in it which can profile all cells. The datalogger will start and stop automatically every time the pack is charged and discharged, respectively. I also changed the chain from #525 RK "x" ring racing chain to #40 stainless industrial chain. The industrial chain absorbs much less energy and will weigh less overall. The #525 was overkill and difficult to work with.

Right now, I've got all the cells out of the bike, they are balance charging. I have determined that three cells burned out last time on my spirited ride though the woods. One cell bubbled out so badly that I had to cut it in half with a sawsall to get it out of the cage! Lithium batteries smell like acetone when you break them open. No sparks, no fire, just fumes and lithium dust (don't know how toxic it is, just kept my face and hands away). I will need to buy two more cells, the price has already dropped to $80/cell. I have gotten rid of the A123 pack because it will just confuse the BMS. Next is to install the cells back in the cages, hook up the new BMS (which means creating a new enclosure for some of it) and put it all back in the bike with the charger again. Hopefully, after careful balance riding, the bike will actually work for a while. Any buyers?