Search found 12881 matches

by fechter
Jan 23 2019 3:47pm
Forum: Battery Technology
Topic: 48v 20ah 3.2v 16s Battery LiFePo4 - I'm New at This
Replies: 11
Views: 138

Re: 48v 20ah 3.2v 16s Battery LiFePo4 - I'm New at This

One of the blue pots will adjust the voltage but I don't know which one. LiFePO4 can tolerate quite a bit of over voltage on charging. I normally charge to 3.65v/cell (58.4v for 16s). This is really close to the voltage for a 14s Li-ion pack. Most spec sheets for LiFePO4 state maximum cell voltage =...
by fechter
Jan 23 2019 3:39pm
Forum: E-Bike Non-hub Motor Drives
Topic: Bafang BBSHD ??
Replies: 7
Views: 408

Re: Bafang BBSHD ??

nemesis03 wrote:
Jan 23 2019 2:26pm
The start-up signal for the PAS was set at 2 so i adjusted it to 3 in the programming and now it is okay.
Thanks for reporting the solution. I don't think I ever messed with that setting.
by fechter
Jan 23 2019 10:44am
Forum: General Discussion
Topic: Free food for mice and they all end up dead!( page 6)
Replies: 146
Views: 5245

Re: Why too much iron from meat is not good!( page 6)

Maybe that's why I weigh so much. ;) Perhaps I should swallow some magnets with every meal? :P That's a bad idea. Swallowing one magnet is fine. Swallowing another magnet is fine as long as you wait long enough for the first one to come out. Otherwise the two magnets will find each other and stick,...
by fechter
Jan 22 2019 5:07pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3048
Views: 180235

Re: Sur-Ron - New Mid drive Bike

So where your at what does “moped regestation” let you do as far as speeds and trails? Insurance and motorcycle helmet? Tom In CA, moped max speed is 30mph, must have insurance and motorcycle helmet. Not legal on most bike trails. Also, moped definition says max 4hp. The Sur-ron in EP mode is prett...
by fechter
Jan 22 2019 8:51am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3048
Views: 180235

Re: Sur-Ron - New Mid drive Bike

litespeed wrote:
Jan 21 2019 4:03pm
So I guess I haven’t been keeping up with the thread.....yours is street legal?

Tom
I was able to get a moped registration for it. I added brake lights, turn signals and mirrors so it appears to have the right equipment. Registration requirements vary considerably from state to state.
by fechter
Jan 21 2019 2:41pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1108
Views: 48633

Re: la Nina rears her ugly head

Another 0.6" last night. I wanted to check out the lunar eclipse but it started pouring right about the time the eclipse started. Luckily there was a break in the clouds right as the eclipse was at maximum, so I wasn't disappointed.
by fechter
Jan 21 2019 2:34pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3048
Views: 180235

Re: Sur-Ron - New Mid drive Bike

While the weather is rainy here, I've been busy working on a few things. I installed a hinge at the rear of the seat made from an old door hinge that I cut, bent and drilled. The front is held down by a really strong magnet that grabs a piece of steel bolted to the front seat bolts. The ends of the ...
by fechter
Jan 20 2019 11:32pm
Forum: General Discussion
Topic: Magnify Glass vs Jewelry Microscope Magnifier Loupe
Replies: 4
Views: 115

Re: Magnify Glass vs Jewelry Microscope Magnifier Loupe

I have several magnifiers I use. I have one that looks like the "Double Lens Head-mounted Headband Reading Magnifier Loupe " you had in the link, only a nice one with glass lenses. This is great when you need both hands. For just reading numbers off chips, I have another single loupe with a long foc...
by fechter
Jan 20 2019 11:29pm
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 142
Views: 2197

Re: APL's DIY axial-flux motor

The copper coils have to "cut" the magnetic flux to generate a force. In a toroid the flux stays in the ring and doesn't get out where the copper is.
by fechter
Jan 20 2019 11:22pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Chaos 48v 1600w scooter upgrade / mods log
Replies: 32
Views: 1062

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

It says 55.7v when on charge, when it's turned off it's 53.9v while it's on 45.7v but when throttle is added 40.1v hope this will be enough for someone to tell me what the problem is, also I've done the battries and they are okay they measure more or less what they should be and when all connect it...
by fechter
Jan 20 2019 2:10pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1108
Views: 48633

Re: la Nina rears her ugly head

Went out riding while there was a break in the rain. There must have been some serious wind during the last storm as the trails were covered in leaves and small branches. Any low spots were flooded and there were several places where water was springing out of the ground and running down the trail. ...
by fechter
Jan 20 2019 12:45am
Forum: Motor Technology
Topic: Ferrite as a stator material?
Replies: 17
Views: 1296

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: 100

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: 100

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: 5
Views: 113

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: 18126

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: 7216

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: 32
Views: 1062

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: 164

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: 3724

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: 1108
Views: 48633

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: 164

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: 3724

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: 245

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: 167

Re: Geared Bafang hub slipping internally

Possibly all the magnets came unglued from the rotor and are just spinning around.