Recent content by J A G

Can you recommend a good BMS that isn't too spendy?

I guess I'll find out. I have two chargers, so maybe that gives me a better shot at having one work. I don't think leakage is my problem. I haven't charged it in months and it is not any more unbalanced than it was. My charger does decrease to about 0.7 A at the end. But that's still 700...

It is resistance discharge balancing. By one pack, I mean one parallel group. The cells were purchased new, and were all tested for capacity (which averaged the nominal 3400mAh almost exactly), then sorted so that each parallel pack had approximately the same capacity. One of the balancing...

Hi all. I've built a 10s 6p battery pack, and I can't get the balancing BMS to balance. Looking at the specs for the BMS, it says that when a pack gets to 4.18V, a balancing charge of 35 mA is applied. But of course, even my smallest charger applies way more current than that, so the whole...

Thanks! I haven't flown with it yet, but when I disassemble it into 10 packs of 6 cells each, then I'm well within the strict regulations, so it should be okay. Each pack is 73 watt-hours, and the limit is 100 watt-hours per battery. FAA / TSA regulations do not limit the number of <100WH...

Here is the finished bike, folded and unfolded. I tried to run down the battery in order to test the charger, and after 24 hours of running at top speed and no load (bike upside-down) it had drained half way. If I give it full power going up hill with my weight on it, which should drain the...

The switch (to avoid sparking) finally came in, so I'm done with the battery. I went with a flat, aluminum-sided pack design, in order to keep the batteries from heating up. I'm working on a way to attach it with magnets, but in the meantime I strapped it on the rack with velcro straps to take...

Yeah, my controller has both brake options -- the three wire one that is powered, and the two-wire one that just shorts. I was going for cheap, as my throttle was ~$3 and the button about a dollar. But I like the idea of engineering the cut-off onto the regular brake. I might try to build...

I hope so. It certainly feels a lot more durable. I'll try to remember to update either way. My latest: I didn't want to use one of the standard brake-lever-style motor cut-outs. I'm adding a front caliper brake, and I will have a lever for that. But I decided that it was a good idea to...

Update on the build, specifically the rack. Several people here mentioned that racks like mine have a tendency to fail at the joint where it is attached near the hub. The idea is that weight on the top torques the rack from side to side, leading to metal fatigue and eventual failure at the...

Another update: the controller has a setting to turn off either the throttle or PAS. When I do that without unplugging anything, the throttle works without the PAS on, although it is still tied to the PAS settings. But the PAS does not work correctly with the throttle turned off. It cuts out...

More progress: In messing with the controller settings, I realized that the PAS level, which can be adjusted with +/- buttons on the display, controls both the throttle and the PAS. That is, when it is set to zero, neither work at all, and when it is set to max, both work as I would expect. The...

Thanks. The BMS has been removed now. I've been going through the controller settings. A few are a but cryptic. But I'll keep trying.

So the throttle came yesterday. I hooked it up, and I'm getting no wheel movement with it at low or medium setting. If I give it full throttle, the wheel moves slowly. I counted and it's about 20 RPM. Current is about .15A. If I put my hand on the wheel, I can stop it, and current goes up to...

I did mess with that and it didn't change anything noticibly.