Search found 13084 matches

by fechter
Mar 25 2019 12:37pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Winter Project... Design and Build an eScooter
Replies: 17
Views: 483

Re: Winter Project... Design and Build an eScooter

Looks great with the fat tires.

What motor are you using?
by fechter
Mar 25 2019 12:07pm
Forum: Battery Technology
Topic: Lead acid anyone?
Replies: 30
Views: 465

Re: Lead acid anyone?

It's my understanding that when flooded lead acid batteries are charging, a small amount of the water in the electrolyte Experiences electrolysis, and some hydrogen is released, which is the "flammable gas" that is of concern. Other than hydrogen gas, and a possible acid burn to your eyes from a sp...
by fechter
Mar 25 2019 9:10am
Forum: E-Bike General Discussion
Topic: Help whit Gazelle BMS
Replies: 7
Views: 113

Re: Help whit Gazelle BMS

Hard to say without some testing, but the blue wire may be sending data to a battery meter on the bike. With a replacement BMS, you would lose this feature. My A2B had something similar. I use a separate battery meter now.
by fechter
Mar 25 2019 9:01am
Forum: Battery Technology
Topic: Lead acid anyone?
Replies: 30
Views: 465

Re: Lead acid anyone?

Anyone care to stay on topic? I haven't kept tabs on the state of LA since the days of Hawker Genesis, but would be interested to know what's going on. It's also embarassing to see vendors of Li-ion and general axe-grinders getting on their soapboxes. Archer123 asked an honest and reasonable questi...
by fechter
Mar 25 2019 8:47am
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3237
Views: 207551

Re: Sur-Ron - New Mid drive Bike

Img_1146A.jpg Had enough break in the rain to test ride a little more. I haven't run the pack to cutoff but I'm pretty sure I can get about 40 miles of hard riding and maybe 50 miles in EP mode with the booster pack. Pack assembly with bracket weighed in at 27 lbs. The booster pack probably needs a...
by fechter
Mar 24 2019 10:50am
Forum: E-Bike Technical
Topic: Cooling Solutions?
Replies: 23
Views: 283

Re: Cooling Solutions?

Ferrofluid won't help as the motor is an inrunner. More fins will help and more air will help. A fan that blows air on the motor would be one option. 60C is getting into the danger zone where things will fail. I see on the mini, there aren't any fins at all. One way to add fins would be to cut a bun...
by fechter
Mar 24 2019 10:43am
Forum: E-Bike Technical
Topic: Bafang eBrake problem and maybe Cycle Analyst
Replies: 4
Views: 83

Re: Bafang eBrake problem and maybe Cycle Analyst

Could I use the 5 volt from my ebrake on my Ezee and sent it to the Bafang I don't see why not. Just put the ebrake wires from both motors in parallel and run it to the brake lever switch. Make sure the ground sides go together. If you are running both motors off the same battery, you could have is...
by fechter
Mar 24 2019 10:35am
Forum: Battery Technology
Topic: Lead acid anyone?
Replies: 30
Views: 465

Re: Lead acid anyone?

Lead acid is still widely used in applications like UPS power supplies, and of course car starting batteries. I've seen various "new" types of lead chemistries come out, but none of them seem to be actually better. Modern AGM batteries with starved electrolyte and calcium plates seem to be the best ...
by fechter
Mar 24 2019 10:29am
Forum: E-Bike General Discussion
Topic: Help whit Gazelle BMS
Replies: 7
Views: 113

Re: Help whit Gazelle BMS

What is the thing the blue wire goes to? I only see the back side in the picture. Many BMS have a separate wire for charging.
by fechter
Mar 24 2019 10:24am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1224
Views: 53928

Re: la Nina rears her ugly head

Finished with .75" yesterday. Finally a weekend with no rain. Rain comes back Tuesday.

Season total a little over 50" so far. This time last year: 20".
by fechter
Mar 23 2019 9:30pm
Forum: Battery Technology
Topic: Salvaged EV cells index: Leaf, Volt, Tesla, Zero, etc
Replies: 54
Views: 11506

Re: Salvaged EV cells index: Leaf, Volt, Tesla, Zero, etc

What happens when reporters don't really know anything about batteries...
The pack comprises 264 cells in 27 modules (88s 3p)
by fechter
Mar 23 2019 11:49am
Forum: Battery Technology
Topic: 26s BMS for 600A max?
Replies: 13
Views: 267

Re: 26s BMS for 600A max?

Right. Just the contactor coil is powered by the BMS so even a really low current rated one would work. Be sure to put a diode (reverse biased) across the contactor coil to catch the turn off spike. Some contactors have this built in.
by fechter
Mar 22 2019 6:50pm
Forum: Items for Sale - New
Topic: JP spot welder
Replies: 1203
Views: 151191

Re: JP spot welder

Good luck with your new work. I sure got my money's worth out of my welder so far. Still working perfect.
Img_1098A.jpg
Img_1098A.jpg (115.07 KiB) Viewed 58 times
by fechter
Mar 22 2019 6:46pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1224
Views: 53928

Re: la Nina rears her ugly head

Coming down here again, but light so far. About 1/3" since this morning. I'm starting to feel pretty soggy.
by fechter
Mar 22 2019 1:03pm
Forum: Battery Technology
Topic: Ryobi Sale - hack together a 72V, 9Ah, Sony VTC6 battery for ~$300
Replies: 22
Views: 514

Re: Ryobi Sale - hack together a 72V, 9Ah, Sony VTC6 battery for ~$300

Right. You can probably get by with a lower current rating as your controller should trip on LVC if any packs go out. If one pack drops out and you keep running the motor, the diode will get very hot. It's hard to miss a sudden 18v drop in battery voltage, so you need to stop right away if you feel ...
by fechter
Mar 22 2019 11:14am
Forum: Battery Technology
Topic: Ryobi Sale - hack together a 72V, 9Ah, Sony VTC6 battery for ~$300
Replies: 22
Views: 514

Re: Ryobi Sale - hack together a 72V, 9Ah, Sony VTC6 battery for ~$300

But I'M not following. Why would the individual BMS see 72 volts? I'm planning to keep the whole pack intact and wire them in series. Each BMS should only see 18v, right? But if one of the three decides to trip, the load (controller) drops to zero and puts the full 72v across the tripped one, which...
by fechter
Mar 22 2019 8:16am
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 166
Views: 7325

Re: Revolt RV-series motor review and comparisons

Do you think that size of the drive sprockets or pulleys would have an influence on the shock loads (the feather key sees)? If we take for example a drive train with 1:5 reduction. one with 10/50T and the other one 20/100T. Same type of chain or belt. I'm sure that has some effect. With smaller spr...
by fechter
Mar 22 2019 7:49am
Forum: Battery Technology
Topic: 3rd ebike battery. This time, doing it right
Replies: 80
Views: 3427

Re: 3rd ebike battery. This time, doing it right

I have a 48v input inverter that runs straight off the pack. I've used it to power my TV and DVD player during a power failure. I missed it a while back, but on your BMS, the unused balance wires should be all tied to the highest cell. If not, you may get false triggers and shutdown as soon as you t...
by fechter
Mar 21 2019 8:03pm
Forum: Battery Technology
Topic: 26s BMS for 600A max?
Replies: 13
Views: 267

Re: 26s BMS for 600A max?

A typical small BMS won’t have a shunt rated for 600A. Otherwise you are correct.
by fechter
Mar 21 2019 3:20pm
Forum: E-Bike General Discussion
Topic: Opinions requested by ambitious greenhorn
Replies: 22
Views: 368

Re: Opinions requested by ambitious greenhorn

A direct drive hub motor can generally handle much more than the rated power for short durations. My A2B motor is officially rated for 500W but I run it up to 2500W. For pavement use, a hub motor is hard to beat. For really steep off road trails, they overheat quickly. MP ride 7 solar farm.jpg The b...
by fechter
Mar 21 2019 2:59pm
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 166
Views: 7325

Re: Revolt RV-series motor review and comparisons

larsb wrote:
Mar 21 2019 2:57pm
I've used the loctite retaining compounds:
https://www.henkel-adhesives.com/us/en/ ... ounds.html
worked well to fit loose shaft to bearing in that application
Which one? There are many.
by fechter
Mar 21 2019 2:57pm
Forum: Battery Technology
Topic: 20s 10p battery build, help with nickel strip needed
Replies: 11
Views: 269

Re: 20s 10p battery build, help with nickel strip needed

Those are some sweet looking packs. 😎 How would you go about fixing the rather large copper busbars to the ends of the pack? Solder? Am I right in thinking you can’t spot weld copper? On mine, the pack has to be split into two halves to mount on the bike. Img_1023.jpg Correct, spot welding to coppe...
by fechter
Mar 21 2019 2:49pm
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 166
Views: 7325

Re: Revolt RV-series motor review and comparisons

Super Loctite was sort of joke. They do make many different flavors though. I used some green "wicking grade" stuff that was almost like welding the parts together. I don't remember the number. It was more like super glue. Yes, any kind of anaerobic locking fluid doesn't work well if there is much c...
by fechter
Mar 21 2019 2:37pm
Forum: Battery Technology
Topic: LiFePo4 starter battery BMS with only 2 leads?
Replies: 18
Views: 318

Re: LiFePo4 starter battery BMS with only 2 leads?

miro13car wrote:
Mar 21 2019 11:08am

LVC off is all that I need
That what it SAVED my battery, many, many times!!!!
No cheap shoddy BMS.
Imagine current on car V6 engine start up battery, what BMS can handle it
How did you do that?
by fechter
Mar 21 2019 9:04am
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 166
Views: 7325

Re: Revolt RV-series motor review and comparisons

Any pictures of failed keyways? One thing that would help is to glue the connection together with super Loctite or something that will prevent any movement between parts. Its when you get a little free play things start to hammer and you get deformation. Just high power isn't the real problem but sh...