I have a battery question. I have seen many cases during my tests that one or more cells drop to zero output voltage then going into negative charge if the...
... to ... value ... cells ... each ... is ... I would think that it is unlikely a cell with be damaged by its mate. The A123 cells should be safe down to...
I was informed Sunday that may battery should arrive this week, so it is time to get everything ready to operate. Although the last details will depend...
... I was able to test the motor with no-load operating ... with ... 80%. ... driving ... .......I would try to seperate out the motor from the drive train. ...
... road ... drive ... How ... I wanted the peak efficiency to be when power is near 100W. Since it drops off quickly at speeds above the peak, I was planning...
... it ... ....My understanding is the efficiency drops really quickly below the optimum power and much slower above the optimum power. If I'd chosen a motor...
... Since ... about ... the ... Higher speed corresponds to lower power. ... was ... I've been searching for someone locally that can reweld them, but no luck...
The NE HPV rally will be at the Burlington Bikefest this year, Oct. 4&5, this year. The website is www.hpvburlingtonbikefest.org. I plan to be there and hope...
... ....Yes the spreadsheets will help determine CdA and Crr butit really requires a datalogger on the vehicle and very careful attnetion to details. I feel we...
I wanted to use a lower impedance shunt than John was using for the current limiter circuit. Six inches of #10 wire would be about 0.5mohm. Trying to get...
... proved ... 2.4Meg ... that ... capacitor ... motor ... I ... It dawned on me that a smaller resistor in parallel with the 2K pot would do the same thing as...
Greetings, I'm keen on the idea of comparing drive efficiencies but, as has been said, getting accurate data isn't easy... Something like the Power Tap [...
Why would you need a torque measuring device when you know the torque output from the motor. You list the Kv - if you convert that to V/rad/sec you have the...
Indeed, for the motor, but I'm interested to find out the drive system efficiency at different power levels, too. Miles ... torque output from the motor. You...
... My impression is that the gearbox losses can be regarded as independent of load if the speed is constant. If you measure the power running the motor alone...
... I haven't seen tests either, but believe that the losses are dependent on belt tension and width and are greater for larger pitch, stronger belts. Why...
Do you think that Matt was operating within the recommended limits? : ) In my case, I wanted to use a smaller than recommended (and commercially available)...
Group: I've just joined the group and wanted to give you a quick introduction and a summary of what I'm trying to do. In working towards an electric assist I...
Hugh, Sounds like quite a project! You said it didn't work too well before but didn't say why. My suspicion is that the efficiency was pretty poor. The motor...
... been ... maybe? ... eLogger... .......Looking a the power Tap manual they only show large wheel information. I wonder about the calibration using a 20 inch...
Miles: Are you trying to measure power (torque) in the shop or on the road. If in the shop you could measure torque with a "prony" brake. If at the rear hub,...
... What? High Kv means a high torque constant - it doesn't have anything to do with no load current. No load current is high with high friction and a low...
... The motor is an ... According to their specs it has a 2.5 Amp no load current so at 10Amps you losing 25% right there. At 20A you have 48 watts of heating....
Chris: Thanks for the response. ... It is for RC airplane use and I've always suspected it will need some cooling. Are the newer bushless motors being used...
Having problems with message search?
Fill out this form to ensure your group is one of the first to be migrated to the new message search system.
