Search found 15134 matches

by fechter
May 17 2022 10:17am
Forum: EScooters/EMotorcycles
Topic: Rebuilt kids electric cross to 3000w
Replies: 39
Views: 621

Re: Rebuilt kids electric cross to 3000w

The CA has several connections it needs to work. Power is pretty straightforward. It needs a current sensor input that is a shunt either inside the controller or an external one. In your case, you might want an external one, but you'd have to buy one. There is also a speed input, either from a wheel...
by fechter
May 16 2022 1:38pm
Forum: Battery Technology
Topic: Bms discharged completely parallel cell
Replies: 1
Views: 52

Re: Bms discharged completely parallel cell

It is not uncommon for many models of BMS to blow a shunt transistor. These are incredibly small, surface mounted things. Unless you have the skill and equipment, replacing it is very difficult. I would recommend replacing the entire BMS unit. You might be able to get one under warranty if you ask t...
by fechter
May 16 2022 12:31am
Forum: Motor Technology
Topic: Combining 2 hub motors into one?
Replies: 11
Views: 190

Re: Combining 2 hub motors into one?

Cool. So assuming I grab 2 phases at random to do this test. The positive and neg from my DC source makes those 2 phases unique and the 3rd phase is not used in the test. So does this mean all the info I need to parallel them is all gained from just one test? So just to check my understanding here....
by fechter
May 15 2022 10:19am
Forum: Motor Technology
Topic: Combining 2 hub motors into one?
Replies: 11
Views: 190

Re: Combining 2 hub motors into one?

As long as the rotors and stators are aligned properly, you can parallel the windings and just use one of the hall sets. You can put the rotors as close as you want. Just make sure the rotor magnets are aligned the same before joining. One way to do this is to apply a steady DC (like 12v) to a pair ...
by fechter
May 15 2022 10:14am
Forum: Battery Technology
Topic: Paralleling batteries, separate charging ports & BMS
Replies: 6
Views: 92

Re: Paralleling batteries, separate charging ports & BMS

If both batteries are connected at the discharge port, only the one getting the charger will be protected during charge. To charge safely, you need to disconnect the packs from each other and charge separately. This will be sort of a pain and if you forget something and connect them when the voltage...
by fechter
May 15 2022 10:03am
Forum: Stand-up EScooter/ESkateboards
Topic: gogotops help rear motor shut down
Replies: 1
Views: 36

Re: gogotops help rear motor shut down

It sounds like there's a short in the phase wires somewhere. To test, you need to disconnect the motor from the controller and see if the drag goes away. If the motor spins freely when the controller is unplugged, then most likely the controller shorted. If the motor still has drag, then the problem...
by fechter
May 15 2022 9:58am
Forum: Battery Technology
Topic: Coulometer blues
Replies: 9
Views: 216

Re: Coulometer blues

Thanks again for posting the instructions. It's been a long time since I installed mine. I typically charge my pack to 58v and had the "full" voltage set to 58v. But over time, the voltage reading had drifted upward so when it was 58v, the TK15 was reading 59v. I didn't see a way to calibr...
by fechter
May 14 2022 9:47pm
Forum: EScooters/EMotorcycles
Topic: Rebuilt kids electric cross to 3000w
Replies: 39
Views: 621

Re: Rebuilt kids electric cross to 3000w

One thing you might consider is looking for a motor sprocket with more teeth. The one that's on there is extremely small and that can't be good for noise and wear. By going to a larger front sprocket, the motor will be geared higher, so more likely to hit the current limit and less likely to wheelie...
by fechter
May 13 2022 10:25am
Forum: EScooter/EMotorcycle Build Threads
Topic: Nova Cruz Voloci Scooter/Bike Info
Replies: 236
Views: 50049

Re: Nova Cruz Voloci Scooter/Bike Info

So how's the acceleration? That is a big controller, but there is plenty of room for it. I think you're going to want bigger batteries :wink: Looks like you could possibly mount the controller between the frame and the seat cushion if you needed a higher (and warmer) seat. Is there a way to re-insta...
by fechter
May 10 2022 2:24pm
Forum: EBike Build Threads
Topic: APL's V4 Cruiser Build.
Replies: 162
Views: 8569

Re: APL's V4 Cruiser Build.

Pack output is up to 1300w, and the fact that it's climbing tells me that there isn't any hard current restriction from the controller or system components. However, it occurred to me that the 18" 8awg battery wires might be sucking up some watts. (36" round trip.) Putting the BMS in the ...
by fechter
May 09 2022 10:37am
Forum: Large EV General Discussion
Topic: 4x4 Transport Kart from scratch
Replies: 18
Views: 1498

Re: 4x4 Transport Kart from scratch

Excellent work! Thanks for sharing it here.

I don't think I've ever seen hub motors like those. Are those geared? Most of them are made to go too fast.
by fechter
May 08 2022 4:28pm
Forum: General Discussion
Topic: Ideal Household Electrical Standards?
Replies: 31
Views: 894

Re: Ideal Household Electrical Standards?

The main reason AC is popular is you can use a transformer. Transformers are needed for long distance transmission lines to get the voltage very high. Otherwise, you'd need very fat wires to carry the current or have huge resistance losses. I guess the other reason is you can run a 3 phase induction...
by fechter
May 08 2022 4:17pm
Forum: EScooters/EMotorcycles
Topic: Rebuilt kids electric cross to 3000w
Replies: 39
Views: 621

Re: Rebuilt kids electric cross to 3000w

In the item description, I see a wire called "3 - speed". If you attach a switch to that connector, you should have 3 speed settings that are pre-programmed into the controller. This would be worth a try. You don't even need a switch to test, just place a jumper wire between the black wire...
by fechter
May 08 2022 11:58am
Forum: Battery Technology
Topic: Coulometer blues
Replies: 9
Views: 216

Re: Coulometer blues

Anybody have the programming instructions for one of those? I have one with a different problem. When I charge, it will go to 100%. When I start riding, the % drops at first, but if I let off the throttle and the battery voltage bounces back, it resets to 100% again. After a few times like this, the...
by fechter
May 08 2022 11:30am
Forum: EBike Technical
Topic: Odd question in learning VESC and FOC-based controllers
Replies: 6
Views: 181

Re: Odd question in learning VESC and FOC-based controllers

IGBTs generally have the advantage when you want to run over about 120v. Below that, MOSFETs will have lower losses.
by fechter
May 08 2022 11:24am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 2372
Views: 158911

Re: la Nina rears her ugly head

They were claiming a chance of rain this morning, but so far there's not a cloud in the sky. Bright and sunny, but windy and cold. I think it's going to miss completely. The ground is completely dried out now and riding conditions are getting like summer. A pic from a couple of days ago. SF bay in t...
by fechter
May 06 2022 11:05am
Forum: Battery Technology
Topic: BMS for regenerative braking. How do i know ?
Replies: 15
Views: 613

Re: BMS for regenerative braking. How do i know ?

With a dual port BMS, the discharge port will stay connected even if the cells go over voltage. This is one way to prevent the BMS from tripping during regen. But you also don't have over voltage protection for the cells. In real life, it's hard to over charge the pack with regen unless you charge t...
by fechter
May 05 2022 11:00pm
Forum: EBike Build Threads
Topic: APL's V4 Cruiser Build.
Replies: 162
Views: 8569

Re: APL's V4 Cruiser Build.

On my A2B, I can only get the motor to draw about 50A, even though the battery, BMS and controller can do more. The limitation is in the motor windings. On flat ground, it will only draw 50A for less than a second, then it tapers down as the speed picks up. On a really steep hill, I can keep it at 5...
by fechter
May 04 2022 10:58pm
Forum: EBike Build Threads
Topic: APL's V4 Cruiser Build.
Replies: 162
Views: 8569

Re: APL's V4 Cruiser Build.

Sounds great. Can you measure the battery voltage during acceleration? Is the controller hitting the current limit? Increasing the current limit is pretty easy on most controllers, but if the battery voltage is too low for the motor wind, you won't be hitting it. If you have more voltage, you'd get ...
by fechter
May 04 2022 8:23am
Forum: Battery Technology
Topic: BMS for regenerative braking. How do i know ?
Replies: 15
Views: 613

Re: BMS for regenerative braking. How do i know ?

One thing to keep in mind is if the BMS disconnects the battery during regen, the voltage on the controller will shoot up and could blow something up. What you really want is a logic signal that will disable the regen if any cells go too high. As long as the output FETs are on, the direction of the ...
by fechter
May 02 2022 9:37pm
Forum: EBike Build Threads
Topic: APL's V4 Cruiser Build.
Replies: 162
Views: 8569

Re: APL's V4 Cruiser Build.

Toggling the power on the orange wire will trigger a reboot. I guess when you shut it off before it was triggering some kind of fault that kept it off until rebooted.
by fechter
May 01 2022 1:35pm
Forum: EBike Build Threads
Topic: APL's V4 Cruiser Build.
Replies: 162
Views: 8569

Re: APL's V4 Cruiser Build.

That looks great. Looking forward to the first test ride report. That said, many of my first rides ended up in "the pedal of shame" when something failed and I had to use human power to get the bike home or I had to stop and fix something on the side of the road. That's why the call it a t...
by fechter
May 01 2022 1:25pm
Forum: EBike Non-hub Motor Drives
Topic: Bafang BBSxx - fault finding and fixes
Replies: 1107
Views: 200890

Re: Bafang BBSxx - fault finding and fixes

SUPERJC wrote:
May 01 2022 12:25pm

if it can help...
Great picture. Thanks for posting. Is that a BBSHD or BBS02?
by fechter
May 01 2022 11:42am
Forum: EBike Technical
Topic: Magnetic Kill Switch
Replies: 4
Views: 194

Re: Magnetic Kill Switch

If your controller has a brake lever input, you could parallel it to one of those. It will stop the motor from running.
by fechter
May 01 2022 11:37am
Forum: EScooters/EMotorcycles
Topic: Kelly KLS-H variable regen issue
Replies: 3
Views: 157

Re: Kelly KLS-H variable regen issue

Sorry, I don't really have experience with that model, but the manual is here: https://kellycontroller.com.ua/download/KLS-H/KellyKLS-HUserManualV1.10.pdf The manual states: (12)Brake sensor Dead Low: Brake sensor Dead Zone Low. Range: 5~40 Functional description: Set throttle effective starting poi...