Recent content by ttobiassen

@ZackClark70 The rest of my system will indeed survive 14S, this is a competitor in the Power Racing Series and they don't like to see nominal voltages above 48V (13S is 48.1) because of some of their safety rules. If the pack wasn't WIRED as 14S while on the race track, then the 14th cell and...

So, I have the following strange problem... I have 7 Leaf battery modules, ie, 14S, that I have wired and working properly with a 14S BMS (discharging at 0.5C continuous, 1.5C peak and charging at 0.1C). This was for project A, now I was hoping to use it for project B. For project B, I want to...

Our go kart did great! We had some SERIOUS sprocket wear and tire wear problems, but none of those is a big surprise for us. The TRANSMAG performed great, as did the Lyen controller, at battery peak currents of about 60A and a continuous draw of 40 A for the whole weekend. I also checked the kV...

Well, the go kart is back to being fast! I just had to set all the "wait, aren't we supposed to leave that alone?" controller parameters to "t-minus 5 minutes to meltdown" for it to work. Not sure what's going on.... The "Speed at full throttle" setting, which historically I've been warned not...

Two quick notes: 1) To test the *potential though unlikely* idea that the 3spd is introducing mechanical drag UNDER LOAD but not at no load, we do have a drop in replacement jackshaft (simple, just a bicycle axle with the correct sprockets on it) that would prove whether or not the IGH is to...

Looks like Roller is going to help me out with the magnet issue, so that's cool. Meanwhile, though... The replacement motor is in, the kV check results in 70-74 rpm/volt like it should, but... We're still slow. With the old, nearly identical motor, when it was new it was REALLY impressive. It...

General follow-up: I just hooked up the spare 532 I had, and it fires up with a kV of 72rpm/volt, just as expected. So, given my competition is less than a week away, that's the good news. The WEIRD news is that the magnets I received in the mail are just barely the wrong size. The old...

Bonus round 1: found this great reference for BH/Demagnetization curves. Very believable that demagnetization is our problem. https://www.kjmagnetics.com/blog.asp?p=temperature-and-neodymium-magnets Bonus round 2: Our Facebook page has lots of pictures of our silly little go kart, in both...

Hey guys. I'll try to fill in the rest of the details for you. The vehicle in question is an entrant into the Power Racing Series, or PRS, in which you take the body of a children's electric ride on toy like a PowerWheels and use it as a template to build an electric go kart. You must stick to...

The peak amps mentioned in my post are displayed via a WattsUp, so even if they're off a little bit because of RSHUNT values, they're self-consistent and have been pretty close in quantity to what the XPD programming says it should be, at least until BEFORE the change occurred. NOW we see only...

More details below, but basically: Lots of hard driving for about 60 minutes of a 75 minute endurance race with pretty consistent performance and current peaks of about 55-60 amps, despite very hot controller and motor temps. IR gun registered 150-170F sustained temperature for motor and...

5404 with 88.8V 20AH should be good for... 3000-4000 watts, depending on your controller. Sounds like a great time. I'm pretty done with hubmotors for the time being because of a) practicality: I hate broken spokes and b) I like gearing. And I'm hesitant to go to a hubmotor that would be beefy...

I've been driving the YUBA around for a couple months now. Certainly looks pretty sweet: BUT! It is not without problems, some specific to the frame, Nexus IGH, and some with the BAFANG BBS02 Problem A: Yuba Dropouts in concert with unconventional Nexus shaft. The Yuba is built to accept...

Looks deceivingly close to completion...

The Yuba is coming together! I got the Sunlite Crusher (wire bead) tires mounted (with difficulty) on the DHL65 wheelbuild and they look sweet. They do NOT fit in the stock Yuba fork, which I am replacing with a Surly Pugsley (100 mm over-lockout version from 2012, since my hubs are 100 mm...