AlanR Posted November 26, 2015 Share Posted November 26, 2015 I was discussing with the proprietor of Milbay in Australia re a series of Face-plants I experienced under benign conditions i.e. average speed 12 kph and battery 3/4 full. He said it was most likely to be an under capacity battery!! My EUC [Dragonmen Hotwheels] battery is claimed to be 132 Wh. Any comments? Link to comment Share on other sites More sharing options...
dmethvin Posted November 26, 2015 Share Posted November 26, 2015 My generic 14-inch 132Wh wheel had a few times when it "sagged" when the battery was about half full or less. It doesn't go that fast so I was able to run them off and avoid a face-plant. I think it might have been that kind of problem where the battery just couldn't handle a sudden high-current draw. However, if you rode it carefully you could run it down to almost no battery. Once I even climbed a really steep hill just before it gave me the low battery beeping. It was the longest trip I ever made, just a hair over 5 miles on a charge. Link to comment Share on other sites More sharing options...
Chuts Posted November 26, 2015 Share Posted November 26, 2015 Most people believe because of the small battery capacity leads to a higher risk of face planting with anything than full battery. This is because of the high variation of voltage shifts when putting the unit under stress and as a result will shut down the unit when voltage dips below a certain threshold. http://forum.electricunicycle.org/topic/459-electric-unicycles-bms-problem-and-solution/ Link to comment Share on other sites More sharing options...
AlanR Posted November 26, 2015 Author Share Posted November 26, 2015 I agree with what you both, dmethvin & Chuts say, but I was doing about 12 kph, level road and 3 lights on! Surely couldn't be more conservative parameters? Link to comment Share on other sites More sharing options...
Compuatic Posted November 26, 2015 Share Posted November 26, 2015 Shunt the battery to skip the BMS and you won't have another face plant. Best mod I did on my unit. Link to comment Share on other sites More sharing options...
SlowMo Posted November 26, 2015 Share Posted November 26, 2015 +1 on shunting the BMS. Link to comment Share on other sites More sharing options...
dmethvin Posted November 26, 2015 Share Posted November 26, 2015 @AlanR When your EUC faceplanted you did you have to reconnect it to the charger to get it running again? If so it's a BMS cutout and shunting would help. For my cases the EUC didn't cut out, it just slowed down when it shouldn't have. Link to comment Share on other sites More sharing options...
AlanR Posted November 30, 2015 Author Share Posted November 30, 2015 On 26 November 2015 9:49:08 pm, dmethvin said: @AlanR When your EUC faceplanted you did you have to reconnect it to the charger to get it running again? If so it's a BMS cutout and shunting would help. For my cases the EUC didn't cut out, it just slowed down when it shouldn't have. No I didn't have to reconnect it to the Charger, I just turned the EUC off and on again to re set! The 2nd and 3rd shut-offs occurred within ~ 3 to 5 mins of restarting! So, are you saying shunting wouldn't help? Is there any other "fix"? The supplier is no help - implied I had done something outside the operating parameters despite saying " about 12 kph, 3 battery lights on" Say they will send me another PCB for me to instal! 2 + weeks and waiting! Refuses to say the new board will work any differently! Link to comment Share on other sites More sharing options...
dmethvin Posted December 1, 2015 Share Posted December 1, 2015 51 minutes ago, AlanR said: So, are you saying shunting wouldn't help? Is there any other "fix"? Usually a BMS cutout requires reconnecting the charger to reset, so it doesn't sound like the problem you experienced was a BMS cutout. It could have been a voltage sag, which might be pretty common for a 132Wh battery because it's not a lot of power. It could also be that you out-leaned the ability of the motor to provide torque. What do you weight and how tall are you? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.