Search found 14867 matches

by fechter
Mar 06 2021 1:27pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 2003
Views: 143004

Re: la Nina rears her ugly head

About 0.3" last night. Chance for a little more next week.

The local water utility issued a drought statement. It's always an excuse to raise the rates.
by fechter
Mar 05 2021 12:45am
Forum: EBike Troubleshooting
Topic: Intermittent no power problem
Replies: 78
Views: 1607

Re: Intermittent no power problem

You only need the 5 hall wires for the motor to run. Most controllers use a hall signal to calculate speed. The white wire is most likely a temperature sensor. You could try measuring resistance from the white wire to the black wire going to the motor. Typical temp sensor is around 10k ohms. Some cr...
by fechter
Mar 02 2021 11:11pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1437
Views: 127351

Re: APL's DIY axial-flux motor

I was trying to think of another test for the core material. One would be to take a core with a bunch of skinny wire turns and feed it a constant current that will come close to saturation, then measure how much pull you get against a piece of thick steel. Repeat with a steel core using same turns c...
by fechter
Mar 02 2021 11:02pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 2003
Views: 143004

Re: la Nina rears her ugly head

That one is going to miss up here. But we'll get a couple of weak fronts over the weekend and into next week. We are way behind average for rain this year.
by fechter
Mar 02 2021 11:00pm
Forum: EBike Troubleshooting
Topic: Intermittent no power problem
Replies: 78
Views: 1607

Re: Intermittent no power problem

The hall sensor signal line is pulled up by a resistor in the controller and the sensor pulls it down. If that resistor was bad, the signal would stay low. If the hall sensor wiring was shorted to ground somewhere, you'd also see the signal stay low. One test would be to place a 10k or so resistor b...
by fechter
Feb 28 2021 12:51pm
Forum: EBike Troubleshooting
Topic: Sondors Ebike problem
Replies: 32
Views: 997

Re: Sondors Ebike problem

I'd guess there is a wire that goes from the throttle switch back to the controller. You should be able to find that wire on the controller end and see that it gets power when the switch is turned on.
by fechter
Feb 27 2021 5:56pm
Forum: EBike Troubleshooting
Topic: Sondors Ebike problem
Replies: 32
Views: 997

Re: Sondors Ebike problem

If you don't see any signs of life on the throttle pins, I'd look at tracing out the power on both switches. Try to see where stops.
by fechter
Feb 27 2021 12:04pm
Forum: EBike Non-hub Motor Drives
Topic: BbsHD MAIN HARNESS DAMAGED
Replies: 2
Views: 152

Re: BbsHD MAIN HARNESS DAMAGED

Finding that piece of wire would be hard. Maybe try posting in the Items Wanted section of the forum and try to find someone that has a fried BBSHD with a good cable. I would just cut out the damaged section and solder the wires back together with heat shrink tubing around them and try it. Depending...
by fechter
Feb 26 2021 8:26pm
Forum: EBike Troubleshooting
Topic: Sondors Ebike problem
Replies: 32
Views: 997

Re: Sondors Ebike problem

I would try unplugging the throttle and measure the pins coming from the controller. You should see something around 5v on one.

I’m not familiar with the Sondors. How do you turn it on? Does anything light up?
by fechter
Feb 26 2021 8:18pm
Forum: EBike Troubleshooting
Topic: Intermittent no power problem
Replies: 78
Views: 1607

Re: Intermittent no power problem

Good ending. :thumb:
by fechter
Feb 25 2021 10:19am
Forum: Battery Technology
Topic: Need help with identifying this BMS
Replies: 5
Views: 160

Re: Need help with identifying this BMS

If the specs in that datasheet are the right ones for that board, it would trip at 30A. The BMS measures the current by measuring the voltage across the two shunt resistor near the B- connection. You can change the trip point by changing those resistors. It's not a bad idea to use fuses anyway in ca...
by fechter
Feb 25 2021 12:39am
Forum: Motor Technology
Topic: Adding hall sensors - Best positions?
Replies: 10
Views: 276

Re: Adding hall sensors - Best positions?

When you apply power to a pair of phase wires and let the rotor find it's spot, one hall sensor needs to be exactly half way between a pair of magnets (right at the trigger point for the hall). Use other phase wire combinations to find the other spots. If the rotor lines up so a pair of magnets is p...
by fechter
Feb 24 2021 11:05pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 454
Views: 29475

Re: C Cab Hot Rod Power Advice

Getting there! Still anxious to see the first test ride results.

But you need those brakes. Don't want to end up like Tiger Woods.
by fechter
Feb 24 2021 11:02pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 1437
Views: 127351

Re: APL's DIY axial-flux motor

That's interesting. I don't immediately see why making it rounded is better. Their comment about lower permeability seems to match with your test results. But you have awesome low iron losses. To make it run faster, you could also reduce the turns.

Are you using delta or wye connection?
by fechter
Feb 24 2021 10:55pm
Forum: EBike Troubleshooting
Topic: Kids 500w fun bike keeps cutting out
Replies: 22
Views: 454

Re: Kids 500w fun bike keeps cutting out

Another thing I've seen done is to hack off the end of a USB cable and use the 5v through a resistor to charge a single cell. Somewhere around a 10 ohm resistor that's physically large should work. The resistor will get pretty hot. You have to watch the voltage like a hawk to make sure it doesn't go...
by fechter
Feb 24 2021 10:52pm
Forum: EBike Troubleshooting
Topic: BBSHD dead Controller
Replies: 5
Views: 226

Re: BBSHD dead Controller

It's possible those parts were just jumpers. Also known as zero ohm resistors. In your case, fuses.

It's always fun to resurrect something that looked hopeless. It may be just fine now as long as whatever originally blew them doesn't happen again. Something like a pinched wire could do that.
by fechter
Feb 22 2021 11:07pm
Forum: EBike Troubleshooting
Topic: Kids 500w fun bike keeps cutting out
Replies: 22
Views: 454

Re: Kids 500w fun bike keeps cutting out

Most chargers cut off way before balancing is finished. A bunch of shallow discharges followed by charges is about the only thing you can do with most. If you had a way to pump a constant 30mA or so into the pack and the balancing shunts will work full time.
by fechter
Feb 22 2021 11:04pm
Forum: EBike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5398
Views: 606083

Re: Sur-Ron - New Mid drive Bike

BCTECH wrote:
Feb 22 2021 3:52pm
tks. the odd shape of the kickstand will be hard to drill / tap straight
[/quote]

I'd take the stand off the bike and put it in a vice and drill from the bottom where it's flat. It doesn't need to be perfectly level.
by fechter
Feb 22 2021 11:02pm
Forum: EBike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 5398
Views: 606083

Re: Sur-Ron - New Mid drive Bike

Forgive me since I'm not super electrically inclined, but would something like this work? https://www.daygreen.com/products/48v-60v-72v-to-12v-50a-600w-dc-dc-step-down-converter-voltage-regulator-w-acc-swtich?variant=11912134950959 My Minn Kota only pulls something like 40 amps at 12v max I think? ...
by fechter
Feb 22 2021 9:26am
Forum: EBike Troubleshooting
Topic: BBSHD dead Controller
Replies: 5
Views: 226

Re: BBSHD dead Controller

I measured those parts on a good board and they both measured near zero ohms. My best guess is they are inductors. You probably have a short downstream of them, most likely the voltage regulator, and they acted like fuses.
by fechter
Feb 22 2021 9:03am
Forum: EBike Troubleshooting
Topic: Kids 500w fun bike keeps cutting out
Replies: 22
Views: 454

Re: Kids 500w fun bike keeps cutting out

If you can bring up the low cells, it might actually work OK. It's not uncommon for cells 1-3 being lower than the rest due to the BMS draining those more than the others during storage. Ideally use a bench power supply or a single cell charger and try to get them closer to the others.
by fechter
Feb 22 2021 8:59am
Forum: EBike Troubleshooting
Topic: Intermittent no power problem
Replies: 78
Views: 1607

Re: Intermittent no power problem

In an actual test, you don't want to be using a 1 ohm resistor. :wink:

I've done a similar setup before but using a little 9v battery as a source. Most hall switches are rated for 24v.
by fechter
Feb 21 2021 8:45pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 2003
Views: 143004

Re: la Nina rears her ugly head

Just barely enough to wet the ground Friday night and nothing in the forecast for at least a week. Nice day for riding today. The hills are turning green barely.
50535EC4-8D99-400B-AADF-8DF4CE144540.jpeg
50535EC4-8D99-400B-AADF-8DF4CE144540.jpeg (4.63 MiB) Viewed 126 times
by fechter
Feb 21 2021 12:26pm
Forum: Battery Technology
Topic: getting cells up to 140f
Replies: 7
Views: 298

Re: getting cells up to 140f

140F would be no problem for most batteries as long as you don't keep them that hot for weeks at a time. It easily gets that hot just sitting in the sun on a hot day. Your particular batteries should have a storage temperature specification you can look up on a datasheet.
by fechter
Feb 21 2021 12:22pm
Forum: Battery Technology
Topic: How does low batter voltage cutoff work? 48v to ??-cutoff
Replies: 11
Views: 266

Re: How does low batter voltage cutoff work? 48v to ??-cutoff

Not sure I follow that, but at a lower pack voltage, the bike won't be able to consume as much power or go as fast, so consumption will be lower. Slower bike gets better range. On many controllers, it's possible to change the low voltage cutoff point by simply changing a resistor. On some of the new...