John in CR
100 TW
Last night I blew a controller that's been proven for 5 years at the same settings. With my newest rig I swapped over the dual Zombiess 34fet high voltage controller and the ventilated HubMonster to my new rig. Though the bike weighs more than my old SuperV, I've lost enough weight to compensate for about the same all up load. The new controller location gets more airflow, so the controllers should run a bit cooler despite the 6% larger wheel and 3% higher pack voltage.
The first week of daily use showed that the controllers were happier, ie not as hot as before. I even took my 100lb son for some long fun rides that included my daily 8-10% grades. Last night we get the bright idea to head up to the wind turbines on the mountain peaks near my house to look at the stars away from city lights. The climb is several kilometers of continuous 20% grade that they built for the trucks to get the turbine parts up there. I've done the climb alone on hot days, so I thought the drive system would be fine. Well it might have been, but it's been so long since I've popped a controller that my number 1 rule slipped my mind.
That is avoid low percentage throttle positions for sustained period with heavy loads, especially steep hills. I've got a box of blown controllers from 6=10 years ago blown from running in the lower third of the speed range during hill climbs. I've even blown a controller at under 5mph on level but very bumpy road due to the same issue, which is short spikes in phase current. While easing up a hill can be easier on a motor, it can mean a quick death of a controller. At low percentage throttle, phase currents spike and overshoot the set phase current limits.
When I made the climb before it was daytime, and I really attacked the climb accelerating hard out of each switchback...accelerating to 80kph on the short somewhat straight stretches. Last night I didn't attack the mountain and now I'm paying the price. Thank goodness I had the foresight to order a spare when I bought the controllers from Zombiess 6 years ago. Hopefully last night was the last time I forget to attack a climb.
One good thing to come of it is to speed up my soon to come off-road beast. I'll run nearly the same power, 25-30kw, into a ventilated HubMonster, but it will be geared down from a top speed of 160-180kph to only about 100kph. That gear reduction will make it so there's no stress on the drive system no matter what speed I ride up hills
The first week of daily use showed that the controllers were happier, ie not as hot as before. I even took my 100lb son for some long fun rides that included my daily 8-10% grades. Last night we get the bright idea to head up to the wind turbines on the mountain peaks near my house to look at the stars away from city lights. The climb is several kilometers of continuous 20% grade that they built for the trucks to get the turbine parts up there. I've done the climb alone on hot days, so I thought the drive system would be fine. Well it might have been, but it's been so long since I've popped a controller that my number 1 rule slipped my mind.
That is avoid low percentage throttle positions for sustained period with heavy loads, especially steep hills. I've got a box of blown controllers from 6=10 years ago blown from running in the lower third of the speed range during hill climbs. I've even blown a controller at under 5mph on level but very bumpy road due to the same issue, which is short spikes in phase current. While easing up a hill can be easier on a motor, it can mean a quick death of a controller. At low percentage throttle, phase currents spike and overshoot the set phase current limits.
When I made the climb before it was daytime, and I really attacked the climb accelerating hard out of each switchback...accelerating to 80kph on the short somewhat straight stretches. Last night I didn't attack the mountain and now I'm paying the price. Thank goodness I had the foresight to order a spare when I bought the controllers from Zombiess 6 years ago. Hopefully last night was the last time I forget to attack a climb.
One good thing to come of it is to speed up my soon to come off-road beast. I'll run nearly the same power, 25-30kw, into a ventilated HubMonster, but it will be geared down from a top speed of 160-180kph to only about 100kph. That gear reduction will make it so there's no stress on the drive system no matter what speed I ride up hills