Search found 11607 matches

by fechter
Jan 20, 2018 5:39 pm
Forum: Motor Technology
Topic: E-Bike Problems
Replies: 2
Views: 19

Re: E-Bike Problems

Could possibly be the brake switches. You could try just unplugging them and test.

Also make sure the battery is charged. If the battery voltage is too low, it cuts off the power.
by fechter
Jan 20, 2018 5:36 pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 663
Views: 51360

Re: Active pre-charge/inrush control

For turn off, you could borrow part of the circuit below (done by one of our members long ago). Just substitute your Schmitt trigger for the input. This circuit provides a fast turn off even with a slow input. The gate driver chip I found can reduce the parts count quite a bit, but maybe not the cos...
by fechter
Jan 20, 2018 4:20 pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 663
Views: 51360

Re: Active pre-charge/inrush control

I think it will work, but it needs to be tested. My spot welder uses the FETs to switch against essentially a dead short, with current over 2000A and they work fine.
by fechter
Jan 20, 2018 4:18 pm
Forum: E-Bike General Discussion
Topic: Marin County, San Francisco Bay Area?
Replies: 19
Views: 211

Re: Marin County, San Francisco Bay Area?

If you live in Marin County, at least one rider is planning to attend the next meeting on this subject. https://electricbikereview.com/forum/threads/voice-your-support-for-ebikes-on-trails-in-marin-county.15866/ https://www.meetup.com/ebiketreks/events/246886216/?_cookie-check=lj6j73uK6dh-Qypv That...
by fechter
Jan 20, 2018 1:54 pm
Forum: Battery Technology
Topic: Solder longevity on nickel
Replies: 4
Views: 48

Re: Solder longevity on nickel

Generally, solder works great on nickel. Good long term.

You may need to use some flux and cleaning the nickel first helps. The mechanical strength of solder is less than nickel, so it will peel if you pull hard enough.
by fechter
Jan 20, 2018 1:24 pm
Forum: General Discussion
Topic: E.S. Quotable Quotes !
Replies: 804
Views: 108932

Re: E.S. Quotable Quotes !

Is that really our Reid Welch? Back from another dimension?
by fechter
Jan 20, 2018 1:00 pm
Forum: E-Bike Photos & Video
Topic: A2b metro gti
Replies: 76
Views: 4771

Re: A2b metro gti

Here is the build thread for my A2B Metro:
https://endless-sphere.com/forums/viewt ... =6&t=50590

I used the stock motor and modified it for an external controller. So much better now.
by fechter
Jan 19, 2018 8:38 pm
Forum: E-Bike Photos & Video
Topic: A2b metro gti
Replies: 76
Views: 4771

Re: A2b metro gti

I have a 14s, 9p pack I put on the back of my A2B. It weighs about 13.5lb. The weight on the rear doesn't really seem to bother the handling much. If I'm just running to the store or a short trip, I use the frame pack, but for longer rides I put the big battery on the rear and have two batteries. 50...
by fechter
Jan 19, 2018 8:30 pm
Forum: Battery Technology
Topic: Chilwee lead-graphene battery
Replies: 11
Views: 155

Re: Chilwee lead-graphene battery

I've never heard of those before. ADVANTAGES * Capacity has been increased 10 - 16%; * Cycle life has been increased 50% more; * Low/High Temperature performance has been improved 30-40%; * Water Loss rate has been decreased 40%; * Large power discharge capability has been increased 15%; * Special c...
by fechter
Jan 19, 2018 8:04 pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 663
Views: 51360

Re: Active pre-charge/inrush control

If you look at the SOA graph for your FETs, you'll probably find this application put them outside of the envelope, but since it's a single event, they seem to survive. The die can absorb some of the heat. The early precharge circuits just used a RC on the gate to slow the turn on, with no feedback ...
by fechter
Jan 19, 2018 7:57 pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: R Martin EVD Moped with HubMonster
Replies: 25
Views: 319

Re: R Martin EVD Moped with HubMonster

6.5v on the lead battery isn't a good sign. Time to recycle. A 50Ahr lithium battery will probably give about twice the range as a 50Ahr lead acid battery. Less weight combined with less Peukert effect. Just for reference, here's the dimensions of a Nissan Leaf battery module. These are 2s each, rat...
by fechter
Jan 19, 2018 3:21 pm
Forum: Motor Technology
Topic: Cromotor issue... bad sound and lack of power
Replies: 9
Views: 83

Re: Cromotor issue... bad sound and lack of power

It sounds like all the magnets broke loose. They can spin around on the inside of the hub, only held on by magnetism. If the glue gets hot enough, it weakens significantly. Ferrofluid could possibly be a factor, but most glues used to stick magnets to the motor should be compatible with it. It would...
by fechter
Jan 19, 2018 3:06 pm
Forum: E-Bike General Discussion
Topic: Marin County, San Francisco Bay Area?
Replies: 19
Views: 211

Re: Marin County, San Francisco Bay Area?

They don't like wind power either. Birds get killed by hitting the blades.

I guess they think it's OK when the birds get killed by global warming instead.
by fechter
Jan 19, 2018 3:04 pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 663
Views: 51360

Re: Active pre-charge/inrush control

That looks a lot like one of our earliest versions. Lots of blown FETs unless you make it super slow.
by fechter
Jan 19, 2018 9:38 am
Forum: E-Scooter and Motorcycle General Discussion
Topic: R Martin EVD Moped with HubMonster
Replies: 25
Views: 319

Re: R Martin EVD Moped with HubMonster

You might be able to fit some Nissan Leaf batteries in there. Even if you fill the entire battery compartment with lithium batteries, it will weigh about 1/3 of the lead batteries.
by fechter
Jan 19, 2018 9:16 am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 619
Views: 20970

Re: la Nina rears her ugly head

0.1" here yesterday. Just sort of drizzled all day.
by fechter
Jan 19, 2018 9:08 am
Forum: E-Bike Technical
Topic: What could be wrong with my bike?
Replies: 18
Views: 372

Re: What could be wrong with my bike?

When I had the connector on the black and blue it would switch between 0.02v and 4.97v as I turned the wheel. The exact same values were there for the black and green. The black and yellow combination went from 0.02v to 4.89v. That sounds pretty normal. I don't think that much difference is a probl...
by fechter
Jan 18, 2018 10:28 pm
Forum: E-Bike General Discussion
Topic: Active pre-charge/inrush control
Replies: 663
Views: 51360

Re: Active pre-charge/inrush control

Food for thought; another possible approach to this problem is to switch the main FETs on hard instead of slowly ramping things up. You'd still need a time delay in the case of not using a switch. Based on what I've seen with the spot welder circuits, I think the FETs would be OK with a fast turn-on...
by fechter
Jan 18, 2018 5:11 pm
Forum: E-Bike General Discussion
Topic: Marin County, San Francisco Bay Area?
Replies: 19
Views: 211

Re: Marin County, San Francisco Bay Area?

After a little more research, it seems it was the hard-core tree huggers that were against the electric bikes, not the MTB gods. The original article states: County supervisors Jan. 9 also approved, on first reading, an ordinance that would amend Open Space District regulations. Several environmenta...
by fechter
Jan 18, 2018 3:08 pm
Forum: E-Bike General Discussion
Topic: looking for tire recommendations for 1200 watt bike
Replies: 7
Views: 158

Re: looking for tire recommendations for 1200 watt bike

Your tire failure sounds like maybe the tire was quite old, possibly sat around on a shelf for too many years. Many people have given favorable reports on the Big Apple tires. If you want really tough tires and are willing to trade off for extra weight and a lot more rolling resistance, you could go...
by fechter
Jan 18, 2018 2:07 pm
Forum: E-Bike Technical
Topic: Replace hall-sensor on throttle?
Replies: 5
Views: 77

Re: Replace hall-sensor on throttle?

The whole throttle is not very expensive in most cases too.

We'd be guessing at the Gauss range. If the range is wrong, the throttle active range might change. Most of the ones I've seen have a pretty high range, like 750 to 1000. One that has a range of 5 Gauss probably won't work acceptably.
by fechter
Jan 18, 2018 2:03 pm
Forum: Battery Technology
Topic: Battery problem, voltage but no current
Replies: 4
Views: 107

Re: Battery problem, voltage but no current

Joachim wrote:
Jan 18, 2018 12:34 pm
the bms doesnt like the current peak to charge the empty controller caps....a smal coil between battery and controller will wurk.
That can happen sometimes too. You'd see a pretty good spark when you make the connection if this was the case. If the BMS is already tripped, you would get no spark.
by fechter
Jan 18, 2018 9:45 am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 619
Views: 20970

Re: la Nina rears her ugly head

Glad I don't live in Siberia: Though the official temperature was "only" 74 below on Tuesday, some residents recorded temperatures as low as 88 below at their homes, the Siberian Times reported. This isn't far from 89.9 degrees below, the coldest-ever officially recorded for a permanently inhabited ...
by fechter
Jan 18, 2018 9:39 am
Forum: E-Bike Technical
Topic: Replace hall-sensor on throttle?
Replies: 5
Views: 77

Re: Replace hall-sensor on throttle?

There are probably many that would work, but you need the right type. The ones found in motors, for example, would not work. You want a linear, ratiometric sensor with a gauss range of about +/- 1000. A Honeywell SS49E or SS496B should work. It would be best to look up the number on the old one to s...
by fechter
Jan 18, 2018 9:20 am
Forum: Battery Technology
Topic: Battery problem, voltage but no current
Replies: 4
Views: 107

Re: Battery problem, voltage but no current

Right, it sounds like the BMS is doing its job and it's tripped. When it cuts off the output, you will still see voltage if measured with a voltmeter, but it will drop to zero with a load. You need to check all the individual cell voltages. Most likely there is one that is out of range. I do this by...