Search found 14150 matches

by fechter
Jan 25 2020 10:44pm
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 282
Views: 26437

Re: Revolt RV-series motor review and comparisons

spinningmagnets recused himself from moderating this topic so that might leave only me here. I'm not going to lock it or delete content. At the same time, people should be careful not to write anything they might later regret because that'll also stay here for the record. I'm not going to sanitize ...
by fechter
Jan 25 2020 3:32pm
Forum: Battery Technology
Topic: How many (V) per (1000w) Output to you drop?
Replies: 20
Views: 329

Re: How many (V) per (1000w) Output to you drop?

A better measurement might be V drop per C (amps) of pack capacity. This would compensate for pack size and voltage but give you a good measurement of internal resistance.

The measurement you get will depend on all sorts of other things like temperature and state of charge.
by fechter
Jan 24 2020 5:36pm
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 282
Views: 26437

Re: Revolt RV-series motor review and comparisons

Exact measurements of the losses will be hard to do. Measuring the no-load power will be a pretty close estimate of the iron losses.
To know the copper losses you need a way to measure the output power (mechanical).
by fechter
Jan 24 2020 1:39pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 4395
Views: 414096

Re: Sur-Ron - New Mid drive Bike

There is a connector for the hall sensors behind the controller but it’s hard to get to. Might need reseating.
by fechter
Jan 23 2020 7:10pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

Please correct me if I don't have this right. With this battery, I will only need one, to operate both motors. (Module of 7, that is) https://www.techdirectclub.com/solar-rv-powerwall-nissan-48-volt-battery-g1-lithium-ion-3-5-kwh-66-amh-w-option-and-1-bms-lot-of-7/ Correct. You can run two motors o...
by fechter
Jan 23 2020 9:01am
Forum: Vendor Relations Corner
Topic: I will never buy from Luna Cycle again, if I don't have to
Replies: 22
Views: 2747

Re: I will never buy from Luna Cycle again, if I don't have to

Angry Bob:
Please review the rules for this section:
viewtopic.php?f=46&t=88469

There are good reasons why some of that content was deleted in the past. If you don't like it, go somewhere else.
by fechter
Jan 22 2020 9:11pm
Forum: Motor Technology
Topic: Lebowski's motor controller IC, schematic & setup, new v2.A1
Replies: 1799
Views: 213095

Re: Lebowski's motor controller IC, schematic & setup, new v2.A1

Yes, totally possible. Probably what I would do. I don’t have any Kelly controllers to look at but if you post good enough pictures we can figure it out. The stock gate drivers should be fine. You want to carefully check out all the FETs on the bricked ones to see if any are blown.
by fechter
Jan 22 2020 1:58pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

1800w at 48v works out to 37.5 Amps. In real life, this will be a peak value and you would normally draw somewhat less than this other than accelerating or going up a hill if you have the gearing right. Let's just ballpark it at 40A per motor. 80A total. From this you can estimate how large of a bat...
by fechter
Jan 22 2020 9:05am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1584
Views: 100988

Re: la Nina rears her ugly head

About 0.3" yesterday here. We'll take what we can get too.
by fechter
Jan 21 2020 3:44pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

A solid axle connected to both wheels will have a real hard time going around corners. Go karts have enough power to make the tires skid. You really want the axle split so each wheel can be driven independently.
by fechter
Jan 21 2020 8:41am
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

If you are using brushless motors, you need a separate controller for each motor but you can split the throttle input to control both. When making a tight turn, the motor on the inside will be effectively geared taller so will take more current. The controllers have current limiting so nothing bad h...
by fechter
Jan 20 2020 12:35pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

Using two of the 1800w motor is not a bad idea. If you can figure out a way to independently gear each rear wheel, the dual motor setup can work like a differential to allow easier turning. With brushed motors, you can easily use two with a single controller. With a jack shaft or large ratio single ...
by fechter
Jan 19 2020 8:54pm
Forum: E-Bike Non-hub Motor Drives
Topic: Bafang ultra,how strong is it.Does it overheat?
Replies: 32
Views: 1932

Re: Bafang ultra,how strong is it.Does it overheat?

Bafang ultra-you can swap from 44-42T chain ring to 38 T with Chain spider BCD 130, or order Christini spider BCD 104 and you can go to 32T chain ring. Programming M620: I do not use throttle, but after programming: the response to pedaling is immediate - both engagement and ending, tried yesterday...
by fechter
Jan 19 2020 12:22pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

Is the "stock" hot rod something with pedals you can actually pedal around? What does it have for a rear axle?
by fechter
Jan 18 2020 8:28pm
Forum: E-Bike Technical
Topic: PAS sensor hype?
Replies: 4
Views: 218

Re: PAS sensor hype?

Do you have a link to a specific model? Many are simple rotation sensors, but your description sounds like a torque sensing setup.
by fechter
Jan 18 2020 8:22pm
Forum: Battery Technology
Topic: Trouble balancing battery
Replies: 29
Views: 662

Re: Trouble balancing battery

Can you post a picture of the BMS? I've used many of the "cheap" style with good results. For badly out of balance packs I use a single cell charger to bring up the low cells. I found some solid strand copper wire that fits nicely into the BMS plug. One the cells were balanced, they have done nicely...
by fechter
Jan 18 2020 12:28pm
Forum: Battery Technology
Topic: Trouble balancing battery
Replies: 29
Views: 662

Re: Trouble balancing battery

Once you get it balanced it should stay balanced for a long time. You could try putting a resistor in series with the charger to limit the current to under 30mA but depending on the charger it might not work because it shuts off when the current drops below a certain point.
by fechter
Jan 18 2020 11:51am
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

I have a bicycle with a gross weight of about 250lb and has a 2000w motor and it can barely go over 25mph. With "car" tires and a lot more weight, I think the power requirements are going to be higher, which means heavier batteries, motor, etc. Also, if you look at the performance of a typical golf ...
by fechter
Jan 18 2020 1:28am
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

Got their reply stating this motor would not be large enough for my application. However, I didn't inform them that I would be making a jackshaft, that would change the gearing. I'm going to send them an update to the jack shaft sprocket choices, and see what their reply will be. I tend to agree. 1...
by fechter
Jan 17 2020 10:07am
Forum: E-Bike Non-hub Motor Drives
Topic: Bafang ultra,how strong is it.Does it overheat?
Replies: 32
Views: 1932

Re: Bafang ultra,how strong is it.Does it overheat?

I put a 38t chain ring on mine. I do a lot of fairly steep trails. It has been working great so far.
Img_1472A.jpg
Img_1472A.jpg (166.64 KiB) Viewed 354 times
by fechter
Jan 17 2020 10:03am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 1584
Views: 100988

Re: la Nina rears her ugly head

About 1.5" here yesterday. It all came in a very short period of time but luckily while I was at work so I didn't get soaked while commuting.
by fechter
Jan 17 2020 12:42am
Forum: E-Bike Non-hub Motor Drives
Topic: Bafang ultra,how strong is it.Does it overheat?
Replies: 32
Views: 1932

Re: Bafang ultra,how strong is it.Does it overheat?

The Ultra is only slightly more powerful feeling than the BBSHD. I think it has more potential though.
by fechter
Jan 16 2020 4:52pm
Forum: E-Bike Non-hub Motor Drives
Topic: Bafang ultra,how strong is it.Does it overheat?
Replies: 32
Views: 1932

Re: Bafang ultra,how strong is it.Does it overheat?

The Bafang Ultra throttle action is like the BBSHD. It sucks. From my observation, it seems like the PAS has priority over the throttle unless you give full throttle so it's like all or nothing. If you don't pedal, then the throttle works like you would expect. As soon as you give some pedal force, ...
by fechter
Jan 16 2020 4:42pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 45
Views: 726

Re: C Cab Hot Rod Power Advice

Cool. The geared motor will be much closer to what you need. It will likely take more than 1800w to go 25mph with that much weight. A golf car rear end + motor would be closer to what you want. Sometimes you can find used ones pretty cheap. Where to put the batteries will be a little harder. A bike ...
by fechter
Jan 16 2020 4:26pm
Forum: Vendor Relations Corner
Topic: Alan Hu Electric Race Technologies. Beware!
Replies: 8
Views: 703

Re: Alan Hu Electric Race Technologies. Beware!

Topic moved to proper section.