Recent content by gge5

I was just going to place my order, but the TP Packs website is selling old printers, software, and movies from the mid 1990's?

There are quite a number of places to buy shunts on the cheap. http://ebike.ca/store/store_accessories.php has a 300A shunt, 0.25mOhm. So that would be 75mV at 300A. I would recommend this one for your ride. That's a 300A continuous rating. I use a 500A, 50Mv ( .1mOhm) Shunt on my 350A...

I believe I've made a noobish mistake. All of these graphs are sampled at 100% throttle, maximum acceleration. However, decreasing the throttle compresses the efficiency curve, effectively raising the motor's efficiency at lower speeds.

Thanks Amberwolf for the link to the simulator. True, they're not the same hub motors, but the physics should be the same. I would have guessed that graph #1 would have been the more accurate one: But according to the simulator, it appears that graph #2 is closer to reality: Can anyone...

I'm planning on building a BLDC hub-motor driven scooter. The motor is 7kW, 72V, and 11.5Kv. I plan to overvolt it to 96V. It should theoretically increase my top speed from 47.2MPH to 62.9MPH. My question: Is motor efficiency a function of (current RPM / maximum RPM)? I'm trying to figure...

This looks really good. I'm looking forward to using this BMS in my 24S, 40Ah scooter.

Ping batteries are rated for 2C continuous, 4C max. 2C from a 10Ah, 36V pack is 720 Watts. That's certainly pushing the boundaries. Headway cells, however, are rated for 5C continuous, 10C max. That would be 1,800 watts continuous from the same size pack. If you buy Headway 10Ah screw...

Hi all. I'm trying to troubleshoot a friend's 2007 Zapino scooter. He recently purchased it from a previous owner. They claim it was dropped on the right side while the power was off, and now power won't go to the wheel. The error LED in the instrument panels flashes 1 and 2 repeatedly. - -- -...

Have you had any progress on your PayPal claim, Spacey? There hasn't been any action on my dispute at all, although PayPal says, "We'll contact you with any developments or if we require additional information from you by Jan 31, 2011." We're a few weeks past that deadline now...

I successfully removed the decals. I tried the oil, but it didn't seem to penetrate. I ended up using a hairdryer on low to gently heat the decals. The first one I heated the entire thing, and it came off in a gooey mess that left sticky residue behind. The remaining three decals I heated...

Is that without using heat?

I've done a lot of work on my X-Treme XM-3500li electric maxi-scooter. I added cells, replaced the dashboard with a digital version, and changed out the controller and motor. It's essentially a brand new bike. At this point I would like to start doing conversions for other people, and I don't...

From personal experience, cold cells definitely affect energy output. Normally my 24 x 40Ah Thundersky pack can get my motorcycle up above 60MPH, but last week it was 39 Fahrenheit and I couldn't push it faster than 47MPH. I was concerned it might be the new controller I put in last month, but...

Haha of course we could go back to the processes of farming and food production as well, but the farther back we go the more unknown variables... I'm just trying to determine the validity of the bicycle calculator, and why there is a discrepancy between it and my calculator. I guess you could...

I can't see the code behind their calculator, or have a complete understanding of the equations they're using. However, it seems to me that the key to the problem is that you're measuring losses in the conversion of electricity to work, where in a human powered bike those losses are ignored...