nutsandvolts wrote:You live on the edge. And you keep that bms-less diode-less case-less pack between your legs?
At least it's not the snug 10" / 25 cm wide it was before (2 batts side by side with some space for bottom 4). Now I don't even notice it at 14 cm wide, the length of a cell. 84v can shock, when perspired or wires getting pressed into you.
I'm not worried about the lithium so much, more a collision with metal object that ends up welded to my cell terminals and potentially burns from the welding heat. All my terminals are on left now, so left side T-Bone with metal at 3 feet high is worst case scenario. But it might have to through the semi-insulating material my left leg is made of. Unless I ride with my legs/feet "recumbent" on the handlebars like I tried for a minute last night, before thinking about how much emergency manouvres are hampered by that.
Run tonight went well. Cop left me alone. 24.4 KM, avg speed 17.6 KMH,max 35.1 on " big whee" hill at 6.5 KM mark.
Started at about 84 volts or so after settling down from topping up on my own charger at 84.7v. I've read you can extend life nicely by only charging to 4.1v per cell or 20.5v per YW batt.Wonder how much ? I keep thinking some fabulous new chemistry will come out within 2-3 years so only need as many cycles as to get through 3 years.
Going up first, biggest nasty Aylmer Marina park set of hills at 18 KM with battery starting at 76v open circuit. Went 10-15 KMH and ended that set of hills with open circuit 72v. Worst part of hill voltage went down to 63v. Hmmm, maybe some bulged cells have high internal resistance ? Will check; that could cause worse than expected voltage drop and drag down whole pack. Anyway, glad I didn't have some wimpy BMS kicking out on me. Last nasty hill the voltage dropped to 57v and my "manual BMS" compensated by dropping throttle.
I've read that dropping Lithium Mg to under 3v per call when under load induced voltage drop is not so harmful like dropping under 3v open circuit. So maybe "manual BMS" is better. If you're tired and bleeding and just want to get home, you may not care about running them to 2.9v.
BTW, I think zig-zagging nasty hills can raise RPM which at full throttle anyway, improves efficiency. Get some interesting motor noises when transitioning from zig to or from zag.
Arriving at home, open circuit voltage was 71v. Now with bike in garage at maybe 15 celcius, it has risen to 77v 1 hour later; it rose to 75v in first half hour. Some of that is normal recovery; some may be warmth rise; it was relatively chilly tonoght; maybe 9 celcius. These batts are supposed to be worse in cold weather.
Charging heaters moving into house now. $30+ ones are useless as loads; must be some solid state stuff. $25 ceramic is noisy. $20 cheapie has no thermostat but is nice and quiet and fan takes little power. I think this fan is the particularly inductive one that gives me spikes though. It now has 2 cords: one for heater/load, the other for fan which during charging is always running at full 120vac speed.
Price of oil dropping but the heaters will be primary this winter, unless heating oil gets a lot cheaper.
Starting to think of "e-sledding" or "e-windboarding"on frozen river this winter. Batts will warm themselves with internal heat. Just need to find some 120vac outlets though. Probably have some on Rideau Canal. Hmmm, maybe just some studded tires on the bike; is that against NCC rules ?