Search found 12870 matches

by fechter
Jan 20 2019 12:45am
Forum: Motor Technology
Topic: Ferrite as a stator material?
Replies: 17
Views: 1260

Re: Ferrite as a stator material?

I would think so. Less loss = more efficient. Go one step further and use an ironless motor.
by fechter
Jan 19 2019 3:53pm
Forum: Battery Technology
Topic: What is " charge recovery voltage" on BMS
Replies: 7
Views: 72

Re: What is " charge recovery voltage" on BMS

As long as none of the cells are over 4v, it should charge. Another thing to try is disconnecting the BMS and reconnecting it, which should reset the monitors. Once reset, it should charge as long as none of the cells are over 4.275v.
by fechter
Jan 19 2019 1:31pm
Forum: Battery Technology
Topic: What is " charge recovery voltage" on BMS
Replies: 7
Views: 72

Re: What is " charge recovery voltage" on BMS

That model apparently does not have balancing, so the recovery voltage is what the cell would need to be drained to before charging would start again after it triggered an overvoltage shutdown but it would need to be drained externally.
by fechter
Jan 19 2019 1:27pm
Forum: E-Bike Build Threads / Photos & Video
Topic: BBS02 problem
Replies: 4
Views: 67

Re: BBS02 problem

I'm not sure what the material is there. You could test with a small magnet.
by fechter
Jan 18 2019 9:26am
Forum: E-Bike Technical
Topic: Make: Fechters' Braking Regen Add-on for BLDC Motors
Replies: 136
Views: 18082

Re: Make: Fechters' Braking Regen Add-on for BLDC Motors

I blew up some stuff testing way back then, but I think it was from stupidly miswiring something and gave up on it. Grafting the power stage from an old brushless controller to the PWM drive from a cheap brushed controller might work OK. The biggest danger is that thing coming on when the main contr...
by fechter
Jan 18 2019 9:12am
Forum: Battery Technology
Topic: The "thermal management of LiPo" thread!
Replies: 91
Views: 7175

Re: The "thermal management of LiPo" thread!

Stuff looks amazing, but there's $17,000 worth of graphite for a $24,000 battery. I reckon aluminium might be a winner hey... Too bad it's so expensive. The article on tab cooling was interesting. Seems more heat is generated on the tab end because the current density is higher. If the tabs were co...
by fechter
Jan 18 2019 8:48am
Forum: Stand-up E-scooters and E-skateboards
Topic: Chaos 48v 1600w scooter upgrade / mods log
Replies: 28
Views: 1003

Re: Chaos 48v 1600w scooter upgrade / mods log

Replaced the controller and it works now, but still don't charge up and the motor barely goes but does work, also does the same with the battery level goes down when throttle is twisted would this be my battries? Thankyou Yes, sounds like a battery problem. If you measure the battery voltage during...
by fechter
Jan 17 2019 3:26pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Electric scooter Overheating Issue
Replies: 7
Views: 142

Re: Electric scooter Overheating Issue

I'm confused how he can put fins on a wheel hub motor? I don't mean to sound sarcastic, I'm genuinely interested to know as I'm trying to understand what you mean? Sent from my SM-G935F using Tapatalk On the sides of the hub were the printing is, glue a bunch of little pieces of aluminum "L" angle....
by fechter
Jan 17 2019 3:20pm
Forum: E-Bike Technical
Topic: bike went full throttle riding in the wet
Replies: 41
Views: 3703

Re: bike went full throttle riding in the wet

You sir are the best! Thank you! I've got the same little cover on the side of the throttle...I also have led indicator lights I've cut the wires to since I don't like them...lol. Did you have to have the throttle off the handlebars to open it or can I keep it on the bars? This is literally the las...
by fechter
Jan 17 2019 9:45am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1105
Views: 48392

Re: la Nina rears her ugly head

A little over 4" since yesterday. That's a lot of rain. It was coming down at some pretty high rates for a while and the street looked like a river. I think some of my riding trails are going to be washed out in spots. At one point last night I was looking out the window and saw an impressively larg...
by fechter
Jan 17 2019 9:31am
Forum: Stand-up E-scooters and E-skateboards
Topic: Electric scooter Overheating Issue
Replies: 7
Views: 142

Re: Electric scooter Overheating Issue

If the outside of the motor is that hot, the insides will be a lot hotter. Too hot and the winding insulation will fail or the magnets can get demagnetized. 60C is about as high as you want it to go. Motor heating is mostly a function of motor current and air flow. Either you reduce the current (not...
by fechter
Jan 17 2019 9:16am
Forum: E-Bike Technical
Topic: bike went full throttle riding in the wet
Replies: 41
Views: 3703

Re: bike went full throttle riding in the wet

Most cheap throttles have exposed legs on the sensor that need to be coated with some kind of insulator. Epoxy, silicone, or even nail polish will work. You need to completely cover the wires from the sensor to where they attach to the cable. Done properly, the throttle should work fine underwater. ...
by fechter
Jan 17 2019 8:54am
Forum: Motor Technology
Topic: Esc current sensing
Replies: 18
Views: 230

Re: Esc current sensing

It shouldn't matter much since there is very little drop across the shunt. I'm measure on the motor side since that's what the FOC algorithm is needing.
by fechter
Jan 16 2019 8:17pm
Forum: E-Bike Technical
Topic: Geared Bafang hub slipping internally
Replies: 9
Views: 154

Re: Geared Bafang hub slipping internally

Possibly all the magnets came unglued from the rotor and are just spinning around.
by fechter
Jan 16 2019 3:26pm
Forum: Motor Technology
Topic: Problem with 10 inch hoverboard hub motors
Replies: 3
Views: 77

Re: Problem with 10 inch hoverboard hub motors

That's an ESC issue. Since the motor runs fine both directions when rewired, the motor itself must be OK. It might have a non-standard hall configuration that doesn't play nice with the reverse feature on the ESC or the ESC has a funky reverse function.
by fechter
Jan 16 2019 3:13pm
Forum: E-Bike Technical
Topic: BBS02 not working no more
Replies: 16
Views: 447

Re: BBS02 not working no more

jpc6000 wrote:
Jan 16 2019 12:37pm
When the problems occur it's was raining
mine first controller, it's was havy snowing
maybe water seepage
I have removed the silicone from controller
and I see black powder on both side of the board
Oh, that explains things. Obviously the board was exposed to water even through the potting.
by fechter
Jan 16 2019 10:06am
Forum: E-Vehicles General Discussion
Topic: escooter
Replies: 1
Views: 87

Re: escooter

The Daymak thing is garbage. Lead-acid batteries.

Search for "banana bike". It might need some lights and stuff, but it has room for enough batteries to go really far.
Banana Bike.jpg
Banana Bike.jpg (77.99 KiB) Viewed 48 times
by fechter
Jan 16 2019 9:54am
Forum: E-Bike Technical
Topic: 2019 16" moped/scooter tire pop-off: which is the most puncture proof?
Replies: 20
Views: 372

Re: 2019 16" moped/scooter tire pop-off: which is the most puncture proof?

I have a 16" moped tire on my A2B. It has survived all kinds of thorns but did flat when it caught a 3" framing nail. Nothing is flat proof, but if the rubber is thick enough and tough enough, not much will get through. Other than the nail, nothing has phased it and has been on some pretty thorny tr...
by fechter
Jan 16 2019 9:44am
Forum: Motor Technology
Topic: SiliXcon FOC Controllers, small, powerful and many features
Replies: 5
Views: 239

Re: SiliXcon FOC Controllers, small, powerful and many features

The big 24.5kW version would be good for a Sur-ron. I wonder if it is a headache to program like an ASI or Sevcon.
by fechter
Jan 16 2019 9:40am
Forum: Motor Technology
Topic: Problem with 10 inch hoverboard hub motors
Replies: 3
Views: 77

Re: Problem with 10 inch hoverboard hub motors

Correct, those motors have to work in both directions so timing should be neutral. Does the ESC have a reverse function? How are you reversing the motor?

If you swap phase wires to reverse it, you also need to swap the hall signals.
by fechter
Jan 16 2019 9:36am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Nova Cruz Voloci Re-vamp
Replies: 161
Views: 19395

Re: Nova Cruz Voloci Re-vamp

It could be a problem if not all the strands have a good connection. It would behave normally at light loads and burn some windings at higher loads.
by fechter
Jan 16 2019 9:32am
Forum: E-Bike Technical
Topic: BBS02 not working no more
Replies: 16
Views: 447

Re: BBS02 not working no more

That is strange. Seems like a failure to communicate between controller and display that's random. Possibly noise getting into the data lines.

After that much trouble, I would probably take a big hammer to it. The BBSHD has a much better track record.
by fechter
Jan 16 2019 9:20am
Forum: Battery Technology
Topic: The "thermal management of LiPo" thread!
Replies: 91
Views: 7175

Re: The "thermal management of LiPo" thread!

See the demonstration: https://www.youtube.com/watch?v=ZAEhyY1_czM It's especially good in the X-Y direction. By using multiple layers, you can get more capacity. For your application, it seems ideal. They use it for flexible heat transfer links like this: PGL S-Link.jpg From https://www.techapps.co...
by fechter
Jan 16 2019 8:52am
Forum: E-Bike Technical
Topic: Geared Bafang hub slipping internally
Replies: 9
Views: 154

Re: Geared Bafang hub slipping internally

With it apart, you should be able to test by blocking the rotor with something and trying to turn the wheel backwards against the clutch. You would need to clamp the axle with something.
by fechter
Jan 16 2019 8:46am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1105
Views: 48392

Re: la Nina rears her ugly head

Close to 2" here since Sunday. A larger system hits later today with high wind and flash flood warnings.