Search found 279 matches

by rocwandrer
Dec 02 2020 10:58pm
Forum: E-Bike General Discussion
Topic: Apples to pomegranates? Q100 vs TSZD2 for low speed trail riding
Replies: 6
Views: 345

Re: Apples to pomegranates? Q100 vs TSZD2 for low speed trail riding

No direct experience, but a friction drive in a mountain bike application seems like asking for trouble.
by rocwandrer
Dec 01 2020 11:07am
Forum: E-Bike General Discussion
Topic: Apples to pomegranates? Q100 vs TSZD2 for low speed trail riding
Replies: 6
Views: 345

Re: Apples to pomegranates? Q100 vs TSZD2 for low speed trail riding

I have a small amount of relevant experience, and you don't have a lot of replies at this point. I've used the Q100 as a front wheel assist with a tiny battery for a few years. have a little experience with a Nakto, and have just built up a BBSHD100. Is the q100 now available in cassette rather than...
by rocwandrer
Nov 11 2020 3:43pm
Forum: E-Bike General Discussion
Topic: shift sensor
Replies: 0
Views: 492

shift sensor

Chinese shift sensor installed. Definitely made shifting worse. It cuts power when the cable moves, and instantly restores full power as soon as the cable stops moving, basically before the shift starts for upshifts, and definitely before it finishes for downshifts. When I pause pedaling, there is a...
by rocwandrer
Nov 10 2020 3:14am
Forum: E-Bike General Discussion
Topic: How do I size the proper mid-drive for off road use?
Replies: 21
Views: 743

Re: How do I size the proper mid-drive for off road use?

Something I didn't see mentioned anywhere, at least with the 860C, holding the minus button is context dependent. When not moving, it activates walking mode, but when moving it activates pause mode, which allows you to shift without power, and then regain power after releasing the button and pausing...
by rocwandrer
Nov 04 2020 1:06pm
Forum: E-Bike General Discussion
Topic: Been away a while... how dumb would it be to buy this?
Replies: 8
Views: 541

Re: Been away a while... how dumb would it be to buy this?

Ended up buying a new bike and going with a BBSHD install.
by rocwandrer
Nov 04 2020 11:04am
Forum: E-Bike General Discussion
Topic: New build: Gravity Monster BBSHD 100mm
Replies: 0
Views: 308

New build: Gravity Monster BBSHD 100mm

I settled on the gravity monster for it's narrower frame with a bunch of successful fitments out there. I settled on the 100mm BBSHD based on reviews saying it fit this frame without drive side spacers. Mine is a 2021 20" frame. It doesn't clear without spacers. By eye, it looks like it needs a...
by rocwandrer
Oct 20 2020 5:32pm
Forum: E-Bike General Discussion
Topic: Been away a while... how dumb would it be to buy this?
Replies: 8
Views: 541

Re: Been away a while... how dumb would it be to buy this?

markz wrote:
Oct 20 2020 3:59pm
You'd need to go mid drive because that bike has through axles.
BBSHD is a good mid drive
The bike I want to power is an old bike that has a 135mm rear dropout.
by rocwandrer
Oct 20 2020 2:55pm
Forum: E-Bike General Discussion
Topic: Been away a while... how dumb would it be to buy this?
Replies: 8
Views: 541

Been away a while... how dumb would it be to buy this?

I want something to use in the woods only for fun. I'm usually that guy who knows stuff and wants to know more just for fun and is helping other people in the situation I find myself in now. Now I really just want to be reality checked by people who know way more than me on this one. What if I just ...
by rocwandrer
May 17 2018 7:17pm
Forum: Electric Watercraft
Topic: 3 wire Minn Kota 101lb trolling motor
Replies: 2
Views: 1401

Re: 3 wire Minn Kota 101lb trolling motor

Yes, i mean the wires from the controller to the motor. I believe these are brushed motors. The 3 wires are heavy gauge red and black and then a lighter gauge light brown wire.
by rocwandrer
May 17 2018 5:18pm
Forum: Electric Watercraft
Topic: 3 wire Minn Kota 101lb trolling motor
Replies: 2
Views: 1401

3 wire Minn Kota 101lb trolling motor

Quick, hopefully easy question... What is the 3rd wire for? I'm building an electric boat for my daughter and planning to use a trolling motor lower unit for assembly expedience.
by rocwandrer
Jul 10 2015 11:49am
Forum: Motor Technology
Topic: Oddball motor application question/creative challenge
Replies: 1
Views: 406

Oddball motor application question/creative challenge

I have a special (personal, not professional) project I need help with. I need a DC motor capable of very high torque for short bursts. Ideally, it should be capable of at least 6000w output for 3 seconds at perhaps 70% of no load speed. More watts would be much better. Duty cycle under these condit...
by rocwandrer
Apr 11 2014 1:19pm
Forum: Battery Technology
Topic: Simple BMS to just prevent high cell voltage?
Replies: 14
Views: 1225

Re: Simple BMS to just prevent high cell voltage?

999zip999 wrote:They are on top of thundersky or calb type cells. What type or brand of cells you plan on using.

I was thinking Headway 38120HP.
by rocwandrer
Apr 11 2014 12:43pm
Forum: Battery Technology
Topic: Simple BMS to just prevent high cell voltage?
Replies: 14
Views: 1225

Re: Simple BMS to just prevent high cell voltage?

Rocwander no worries. Welcome to the shark tank. I have seen single cell bms on top of bigger lifepo4 cells. Anything that achieves some degree of balancing without limiting discharge current or being very costly? Did it look anything like what I described above? I only need 4 cells worth, and with...
by rocwandrer
Apr 11 2014 9:59am
Forum: Battery Technology
Topic: Simple BMS to just prevent high cell voltage?
Replies: 14
Views: 1225

Re: Simple BMS to just prevent high cell voltage?

why come here and ask if you don't wanna listen to others advice. if you need a free yes man then you should get married. you never explained what the reverse parallel diode trick does. The important piece of any advice is to understand the why. That is where the value is. I understand why a BMS is...
by rocwandrer
Apr 11 2014 9:19am
Forum: Battery Technology
Topic: Simple BMS to just prevent high cell voltage?
Replies: 14
Views: 1225

Re: Simple BMS to just prevent high cell voltage?

He must be a Very Smart Guy to solve this Simple issue with zeners, transistors and resistors. I would be very happy to see this finally happen! :) The disconnect here, if any, has nothing to do with intelligence and everything to do with training and experience. This is far outside of my area of e...
by rocwandrer
Apr 10 2014 10:04am
Forum: Battery Technology
Topic: Hobby King LiFePo4
Replies: 53
Views: 9610

Re: Hobby King LiFePo4

How many cycles by now? I'm estimating 72 over the last 16 months. I stopped keeping track at 60. 59 was the day I broke my leg, April 19, 2013. Battery sat at ~75%SoC and room temperature until sometime in October, at which point the balance charge was similar to what it took when using it every d...
by rocwandrer
Apr 09 2014 11:27pm
Forum: Battery Technology
Topic: Simple BMS to just prevent high cell voltage?
Replies: 14
Views: 1225

Re: Simple BMS to just prevent high cell voltage?

For this application (ice starter battery), charge and discharge must be the same terminals. I was thinking zener diodes in reverse parallel (with appropriate resisters to keep things from burning up). Waste a watt or so anytime an individual cell voltage is above 3.4v to keep things aimed at more i...
by rocwandrer
Apr 09 2014 11:39am
Forum: Battery Technology
Topic: Hobby King LiFePo4
Replies: 53
Views: 9610

Re: Hobby King LiFePo4

Update: 4.5 ah rated packs took 2.950 ah to fully charge last charge cycle, and 0.3 ah of that was balance charging. For this depth of discharge, that's about double the balancing required previously. At the start of the discharge cycle, all cell pairs were within the measurement resolution I have o...
by rocwandrer
Apr 09 2014 11:29am
Forum: Battery Technology
Topic: Simple BMS to just prevent high cell voltage?
Replies: 14
Views: 1225

Simple BMS to just prevent high cell voltage?

I'm looking for an inexpensive solution for ensuring no cell in a 4s1p LiFePo4 pack gets overcharged when using a constant voltage series charger (14v). I don't care about over discharge protection, etc, and specifically do not want a discharge amp limit. Input?
by rocwandrer
Jan 09 2014 10:41pm
Forum: E-Vehicles General Discussion
Topic: Electric goKart for SCCA solo2/autocross
Replies: 18
Views: 3641

Re: Electric goKart for SCCA solo2/autocross

So what happened to this project?
by rocwandrer
Oct 29 2013 4:22pm
Forum: E-Bike Reviews & Testing
Topic: BMSBattery/ECityPower Experience
Replies: 391
Views: 27931

Re: Sine wave controllers @ bms battery

Silly question maybe, but I searched here after it wasn't clear on the BMSBattery site.... These controllers can be run throttle only, and do current control in proportion to throttle position, rather than voltage control, yes?
by rocwandrer
Oct 25 2013 10:09am
Forum: Battery Technology
Topic: Hobby King LiFePo4
Replies: 53
Views: 9610

Re: Hobby King LiFePo4

My goals match arbol's. I have not checked internal resistance yet. I rode my bike for the first time since I broke my leg in April just today. I left the pack in indoor storage, at roughly 75%SOC, and did nothing with it for 6 months. All cells read within my measurement error of the same today. mo...
by rocwandrer
Aug 14 2013 12:52pm
Forum: Battery Technology
Topic: Hobby King LiFePo4
Replies: 53
Views: 9610

Re: Hobby King LiFePo4

90% discharged @ 3V resting voltage is pretty normal for lifepo4 pouches from my experience. can you do your internal resistance measurement using two different loads? measure the voltage and current at one current and then add a second load to it and measure the voltage and current there to determ...
by rocwandrer
Aug 14 2013 10:43am
Forum: Battery Technology
Topic: Hobby King LiFePo4
Replies: 53
Views: 9610

Re: Hobby King LiFePo4

I got fully charged cells to sag to 3v/cell at 2.5C (based on discharge capacity to 3.0v resting, which puts a "4500 mah" pack at about 4ah))
by rocwandrer
Jul 10 2013 4:28pm
Forum: E-Bike Technical
Topic: Inexpensive source for an oscilloscope?
Replies: 21
Views: 1593

Re: Inexpensive source for an oscilloscope?

the thread bump reminded me to update this... We are evidently going to use arduino as an oscilloscope.