Search found 12013 matches

by fechter
Apr 25, 2018 11:25 pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Nova Cruz Voloci Re-vamp
Replies: 88
Views: 13237

Re: Nova Cruz Voloci Re-vamp

Great historical summary!

I have copies of the firmware for re-flashing a corrupted controller. I also have the AVRISP programmer unit and instructions. Used once.
by fechter
Apr 25, 2018 9:44 pm
Forum: E-Bike Technical
Topic: battery discharge unevenly
Replies: 6
Views: 77

Re: battery discharge unevenly

The cells are supposed to drain evenly. The most common problem is a bad BMS that has the balancing shunt stuck on. If you charge the cells, then remove the charge current and watch the voltage for a while. You can see a steady decline if it's being drained. I would not rule out two bad BMS units. D...
by fechter
Apr 25, 2018 3:37 pm
Forum: E-Bike Non-hub Motor Drives
Topic: Throttle Behavior
Replies: 70
Views: 1797

Re: Throttle Behavior

The 100K resistor was turned down under 20K when I installed it, and adjusting it up or down one full turn made no noticeable difference. From previous tests I have made It seemed that with a straight 100K resistor there was no change to the controller functionality and with 0 resistance neither PA...
by fechter
Apr 25, 2018 1:15 pm
Forum: General Discussion
Topic: Registering and Insurance
Replies: 8
Views: 83

Re: is registering and insurance required on e bikes and e scooters

For sure depends on where you live.

In California, a 750W scooter is treated the same as a Class 2 ebike and no insurance or registration is required.
by fechter
Apr 25, 2018 1:12 pm
Forum: E-Bike Technical
Topic: battery discharge unevenly
Replies: 6
Views: 77

Re: battery discharge unevenly

Sounds like the BMS drained the cells unevenly during storage. Once a cell gets below about 2.5v, it is in a danger zone for charging. Low cells need to be charged at a very low C rate until they get above 2.5v or so. Too much current on a low cell can damage the cells. Yours sounds like it's right ...
by fechter
Apr 25, 2018 1:05 pm
Forum: Battery Technology
Topic: Will 60V work on my e-Bike
Replies: 10
Views: 100

Re: Will 60V work on my e-Bike

It could be your existing controller is maxed out on power at top speed as the wind resistance will be a lot. Increasing the current limit on the existing setup might get you more top speed. You could also consider a new controller that has a 'field weakening' feature that will spin the motor faster...
by fechter
Apr 25, 2018 8:31 am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: mongoose mx250 2 wheel to Trike
Replies: 2
Views: 30

Re: mongoose mx250 2 wheel to Trike

Wow! Nice work! Lucky kid.

Does it lean in corners?
by fechter
Apr 25, 2018 8:15 am
Forum: E-Bike Technical
Topic: Battery and live wire help
Replies: 7
Views: 119

Re: Battery and live wire help

It sounds like the BMS tripped prematurely. This may indicate the cells are not balanced in the pack. Restoring the balance is a pretty slow process with most typical BMS circuits and depends on how the charger works. Balancing will only happen when the pack voltage is at the maximum. Typical balanc...
by fechter
Apr 25, 2018 7:58 am
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 709
Views: 58492

Re: Active pre-charge/inrush control

Fried_guinea_pig2.jpg Fried guinea pig award hasn't been seen for many years, but you earned it! Bummer on the smoke release. If the UPS failed and shorted, it may be the reason the switch circuit blew up. Maybe something I'm not understanding, but if it worked with a 4 ohm resistor, why not stick ...
by fechter
Apr 24, 2018 3:12 pm
Forum: General Discussion
Topic: Forum software upgrade on 11/17/2017 technical issues thread
Replies: 147
Views: 13266

Re: Forum software upgrade on 11/17/2017 technical issues thread

Alan B wrote:
Apr 24, 2018 3:07 pm
Thanks for your effort!
+1

I wish I could do more of it myself but I have a poor track record with databases.
by fechter
Apr 24, 2018 3:01 pm
Forum: E-Bike Technical
Topic: Battery and live wire help
Replies: 7
Views: 119

Re: Live wire help.

It's a little hard to see in the picture. You might be able to snip away part of the case to get a little more of it to work with. If it was mine, I would just put a little blob of epoxy or silicone over the end so nothing can short out and use a separate USB converter. If this is something that nee...
by fechter
Apr 24, 2018 2:42 pm
Forum: E-Bike Technical
Topic: Wire Type
Replies: 7
Views: 97

Re: Wire Type

20 ah is the capacity of the battery. That doesn't really matter.
What matters is the motor current or how many watts the motor will take.

If the motor is limited to 20A, then 12ga will be fine. It will barely get warm. I've run 50A with 12ga.
Using heavier wire is OK, but probably unnecessary.
by fechter
Apr 24, 2018 8:34 am
Forum: E-Bike Non-hub Motor Drives
Topic: G510 Bafang New Bicycle Build
Replies: 2
Views: 132

Re: G510 Bafang New Bicycle Build

Looks great.

Does that one have torque sensing?
by fechter
Apr 24, 2018 8:22 am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Nova Cruz Voloci Re-vamp
Replies: 88
Views: 13237

Re: Nova Cruz Voloci Re-vamp

Not sure exactly why the on board dc-dc quits at the higher voltage. It might be on the verge of blowing up. A separate dc-dc should work fine. You could go for a separate battery meter too. I have had good results with the little TK 15 units. These actually measure the amp-hours, so give you a pret...
by fechter
Apr 24, 2018 8:16 am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 771
Views: 28324

Re: la Nina rears her ugly head

Sounds like La Nina is over and it's back to neutral conditions Most models in the IRI/CPC plume predict La Niña will decay and return to ENSO-neutral during the current March-May season [Fig. 6]. The forecaster consensus similarly favors a transition to neutral, with a continuation of ENSO-neutral ...
by fechter
Apr 24, 2018 8:05 am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 992
Views: 50486

Re: Sur-Ron - New Mid drive Bike

anybody found info on re calibrating the speedo with the different sprocket size? Not that I am aware of. It seems it gets the speed from the motor hall signals. There must be some kind of programming interface for the controller but I don't think anybody outside of SurRon has it. Plan B would be t...
by fechter
Apr 24, 2018 8:00 am
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 105
Views: 1748

Re: The ultimate torque arm (For <2kW and standard axles)?

You mean you engineering wizards can't work that out from the information given. Come on Chalo, now's the time to step up and show everyone your prowess. It's a simple calculation; just get the units right. Clipboard03.jpg Nowhere in this screen shot does it show where the 200N is applied nor does ...
by fechter
Apr 23, 2018 11:20 pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 105
Views: 1748

Re: The ultimate torque arm (For <2kW and standard axles)?

200 N That's not a torque, son. My thought also. In the diagram, it is not evident to me where this 200N is applied, so you need to help us out. I am interested in what the amount of torque would be at that stress for comparison reasons. I know how much torque my hub motor can make. I want to know ...
by fechter
Apr 23, 2018 7:19 pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 771
Views: 28324

Re: la Nina rears her ugly head

82 and sunny here today. I think it's close to a record. Slight chance of rain on the weekend.
by fechter
Apr 23, 2018 7:17 pm
Forum: E-Bike Technical
Topic: The ultimate torque arm (For <2kW and standard axles)?
Replies: 105
Views: 1748

Re: The ultimate torque arm (For <2kW and standard axles)?

Buk___ wrote:
Apr 23, 2018 5:37 pm
Exactly as predicted (by me!) in both location and magnitude; and entirely within the proof stress of the material selected.

What was the axle torque to produce that stress?
by fechter
Apr 23, 2018 3:15 pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 992
Views: 50486

Re: Sur-Ron - New Mid drive Bike

Sweet! Not exactly plug and play, but with enough work... The smaller ones might be the same as stock. Interesting they say the controller is FOC. SUR-RON-C2-SERIES.jpg Rated Voltage 60 V Operating Voltage Range 36 V ~ 100 V Continuous Output Power (60 min) 16 kw Peak Output Power (2 min) 28 kw Spee...
by fechter
Apr 23, 2018 3:08 pm
Forum: E-Bike Non-hub Motor Drives
Topic: Throttle Behavior
Replies: 70
Views: 1797

Re: Throttle Behavior

Good deal. You get to be the guinea pig.. What works nice is to have the pot hanging out on long wires so you can adjust while testing, then once you get it all dialed in, carefully disconnect the pot and measure the value with an ohmmeter. Then you know which fixed resistors to use in the future. I...
by fechter
Apr 23, 2018 2:55 pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 709
Views: 58492

Re: Active pre-charge/inrush control

The footprint that I used for the PNP transistors is wrong, CBE instead of EBC, Q3, Q6 and Q8. That's why the protection was triggered, probably why it blew up too. I hate it when that happens... I'll be interested in the results. I took a stab at designing at a similar circuit using a FAN3224 dual...
by fechter
Apr 23, 2018 1:09 pm
Forum: Resources & EV Related Parts and Services
Topic: Throttles, connectors, accessories, - Where to buy them?
Replies: 26
Views: 16319

Re: Throttles, connectors, accessories, - Where to buy them?

What are the basic mechanisms behind thumb throttles? I wish to design and produce my own. Is it some kind of spring-loaded potentiometer? Most of them use a hall effect sensor and moving magnets. You can use a potentiometer as well, but those tend to have limited life as the wiper wears out. There...
by fechter
Apr 23, 2018 9:58 am
Forum: E-Bike Non-hub Motor Drives
Topic: Throttle Behavior
Replies: 70
Views: 1797

Re: Throttle Behavior

Unfortunately, I did not have time to test the circuit over the weekend. I looked around to see if there was a voltage detector that might work, and they do exist. A voltage detector will switch at a preset level and should be pretty immune to temperature changes. I found some that will trigger at 0...