Endless Sphere

The resistance to turning the wheel that goes away when the phase wires are disconnected from the controller is a sure sign of shorted mosfets in the controller. It quite commonly occurs during a takeoff when the controller is already hot from use, because takeoff is when phase currents are the high...

Personally I would never use pure nickel strip for series connections, because nickel has 4X the resistance of copper. Instead I'd used nickel plated copper strips to retain the easy to tab weld properties of nickel as well as its resistance to corrosion.Pure nickel strip is fine for the parallel co...

I'm trying to help you not make the same mistakes plenty of engineers have made when approaching an EV build. Everyone who's mechanically inclined thinks in the beginning that they'd somehow be better off with a clutch and multiple gears. I thought the same way too. Even Tesla wasted millions in the...

How do you know the controller is fried and not the motor or both, since a motor failure can fry a controller? Other culprits stopping your ride could be the throttle, the brake cutoff, or even a bad connection anywhere in the electrical pathways. If you don't already have a basic multimeter and ebi...

The problem with putting series strings together in parallel with only small gauge parallel connections at the cell level is, what happens when one cell in the pack is weak or is dead. ie high current will try to pass through small wires. Other than maybe some of those handmade Chinese packs that so...

Yes, I understand that. That is why I was so sure that I tried auto, then shanged to remote when it did´nt work. But when I later shanged to auto again for whatever reason, I noticed that the switch worked. Ah, I'm not the only one with some "ghosts in the machine" activity that magically disappear...

Strings to me means multiple cells or batteries, so it applies best to series. Parallel "groups" can essentially be treated as if together they are a single cell with the summed amp-hour capacity. While you can group series strings together in parallel, if they aren't paralleled together at the cell...

First do JohnCR trick of swapping any two wires as I read he can do it in 6 tries ? It took me 36 and a piece of paper and and only one worked ? After the 22nd I kept going just to know. A bmc 600 geared a very fickle motor. Don't worry you will find it. Good luck. I've heard the story of 1 in 36 f...

No, but the flow chart thing is a bit of a time waster too. Wiring configs are a simple problem with a simple solution that I explained in a few sentences. I could do it blindfolded, so anyone can do it.

Dual Nucs is working great on my 6 phase motors. I can't wait till the master slave option is up and running, so my display gives system stats. One difference I found that is different from the Control support section recommendation is when using a switch for on/off, setting one controller to source...

If no self leaning is taking place with the controller, then you are getting mixed results...a true reverse and a false positive reverse denoted by a rougher start, a lack of torque, higher no load current, and typically higher max rpm due to the advanced timing of the incorrect wiring config. If it...

Time to back up a bit. How much does that thing weigh without motor, transmission (not needed unless you need a low gear for long mountain climbs with a big load), gas tank, etc? It looks heavy to me, and if you're going to all the trouble of building a beautiful EV you want it to be fun. It's not t...

The volt battery performed nicely, it was a modded meanwell that short circuited while charging that ultimately fried the battery. I don't think you can have both factory wiring and keeping it close to bike width. You could possibly maybe get a large section cut out with the original busses but it ...

They are down to single cells clean and ready to build into custom sized packs. Yes, but that's so much work, and I by far prefer to use factory connections when possible. My Volt modules perform beautifully, and you killed yours, though possibly due to aggressive charge/discharge levels...or not a...

...and all that sag Amberwolf is showing you is coming just from the internal resistance of the cell, so it's all turning to heat. Do the math and heat problems are guaranteed at 500A even with perfect connections to and between the cells. If ridden fairly easily with short bursts of high current th...

Just recently got the Tesla Model 3 battery in and managed to keep a segment together while dismantling. I plan on making it 16s4p and was thinking of wiring it with fuse wire in the Tesla fashion. Need some opinions please. 20191120_144034(1)~2.jpg Also have a few hundred cells available to buy fo...

Cylindrical cells arranged in straight rows and columns like that wastes a ton of space, and space is the biggest premium on our ebikes. Instead of those holders, I'd suggest gluing the blocks of parallel cells in a staggered alignment like Tesla does. Don't use hot glue like some do, as it simply ...

I find it hard to believe that your cells are within 1.5% after repeated use and charging cycles. You must be accustomed to the crappy batteries so commonly used. Get yourself some automotive grade batteries and then you'll understand. BTW my packs are many times closer to perfect balance than 1.5%...

Cylindrical cells arranged in straight rows and columns like that wastes a ton of space, and space is the biggest premium on our ebikes. Instead of those holders, I'd suggest gluing the blocks of parallel cells in a staggered alignment like Tesla does. Don't use hot glue like some do, as it simply d...

The most important thing is not a BMS. The most important thing since your intended use is on a boat is keeping the battery dry, especially if used in salt water. Automotive grade batteries maintain balance so well with conservative use that with conservative charge and discharge levels occasional c...

How do you reconcile the fact that using 1 cheap 20s BMS board is scary with the fact that 20 cheap 1s charger boards is over 20 times scarier, especially since in the best case they are killing your pack much faster and result in greater pack imbalance after one day than I have had in 11 years runn...

Something I've done with chargers that will get mistreated and exposed is to build a wooden box and secure the charger in it. Then I mount 2 larger diameter more quiet fans (for redundancy in case one fails), one at each end of the box (one blowing in and one blowing out). Be sure to orient the char...

The 25kph max speed listed seems reasonable. 20km on the 8ah battery doesn't seem reasonable though unless conditions are perfect...flat and smooth with dedicated cycling infrastructure, which is the only way I rid a little folder like that. That is perfect conditions and lots of pedal assist for th...

Most likely some super crappy motors to begin with with quite poor copper fill.

Where the hell are our cheap room temp superconductors? In the meantime I'll take some motors with cast copper windings for maximum fill.

Sounds like a pretty good motor. What's the phase-to-phase resistance? To me that's the most important spec when it comes to real world power handling. Personally I like much lower rpm for a quieter ride and accept the added motor weight, but for grins what's the no load current at the high rpm?