Search found 380 matches

by thunderstorm80
Sep 12 2016 1:03pm
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Re: Why 50V-60V is considered the optimum battery voltage?

It also seems, that the CA and the Phaserunner has their share of problems when running on 72V. I run a flashlight via the CA DC port (Grin flashlight), and I happened to trip the protection circuit of the phase-runner more than once, and Grin told me it's probably because it's tripping due to the h...
by thunderstorm80
Sep 12 2016 1:01pm
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Re: Why 50V-60V is considered the optimum battery voltage?

Yeah,, 72v needed to go that fast on that motor. There is your need that requires 72v. But 72v 40 amps can overheat those motors if run hard very long. So easy does it on the longer 10% hills,, I mean like if it will take longer than 15 min to climb it. A 9c can easily take 72v 20 amps, for a very ...
by thunderstorm80
Sep 12 2016 12:52pm
Forum: E-Bike Technical
Topic: 2WD can increase regen efficiency?
Replies: 7
Views: 962

Re: 2WD can increase regen efficiency?

What the sim may not show, is regen on a motor with big magnets will really slow you down. Do you really want to descend mountains at 5 mph? Your setup is ideal as it is, for running one motor on the flat, and two on the slope. It would work equally well though, to run one big motor at lower power ...
by thunderstorm80
Sep 12 2016 4:28am
Forum: E-Bike Technical
Topic: 2WD can increase regen efficiency?
Replies: 7
Views: 962

Re: 2WD can increase regen efficiency?

Yes. That's what I am thinking, but wanted to get some other opinions about this. If it's a really heavy bike - for example when doing touring with camping gear + going down steep downhills, then the 2706 recoop eff goes down somewhat, and then a locked-clutch ezee can still recover almost the optim...
by thunderstorm80
Sep 11 2016 9:10am
Forum: E-Bike Technical
Topic: 2WD can increase regen efficiency?
Replies: 7
Views: 962

2WD can increase regen efficiency?

Hi, I have two motors - front 9C+ 2706 which is a direct drive, and rear geared ezee 250rpm, and I live in a very hilly city. (grades of 10%+) I use only the 2706 on flats and at downhills the 2706 recovers a significant portion of the energy! I kick in the ezee during uphills and also for short tim...
by thunderstorm80
Sep 11 2016 9:00am
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Re: Why 50V-60V is considered the optimum battery voltage?

Optimum to do what? Step one,, figure out what you want to do,, then we can start making suggestions. If you want a max speed under 30 mph,, then most typical hub motors would reach 27-30 mph on 48v (54.6 v full). That's why its optimum, cuz you don't look like a hooligan going 25-30 mph and cops c...
by thunderstorm80
Sep 11 2016 6:01am
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Re: Why 50V-60V is considered the optimum battery voltage?

High amps at any voltage can cause very serious burns. There are many examples of 12V car batteries that are shorted through a metal ring on a metal wrench and someones finger. There is no voltage that is safe when talking about high amps. Once we accept that the amps are a danger that we must be c...
by thunderstorm80
Sep 11 2016 5:54am
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Re: Why 50V-60V is considered the optimum battery voltage?

There are more efficient FETs available for nominal 52V operation than for higher voltages. That means less heat management problem solving to do, and of course more battery watts that make it all the way to the the wheel. As I said, I use Justin's Phaserunner and CA, which are rated all the way up...
by thunderstorm80
Sep 11 2016 5:52am
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Re: Why 50V-60V is considered the optimum battery voltage?

I think it depends on the context that the recommendation was given. For some motors that's normally a bad idea. your 250w eZee, for example, would probably fail at higher voltages. it's not built for handling the kind of speed the higher voltage would give, and you'd either melt the winding s or d...
by thunderstorm80
Sep 10 2016 1:45pm
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Re: Why 50V-60V is considered the optimum battery voltage?

What motor and controller setup ? I run 72v for the speed. But my next commuter build will be with a 52 volt just for size and weight. Use high quality cells for long lasting battery. I have two motors - front 9C+ 2706 DD and rear ezee250rc. Each controlled with it's own Phaserunner. (Both together...
by thunderstorm80
Sep 10 2016 12:47pm
Forum: E-Bike Technical
Topic: Why 50V-60V is considered the optimum battery voltage?
Replies: 70
Views: 8060

Why 50V-60V is considered the optimum battery voltage?

Hi, After being told my 72V system is not recommended and that I should work with no more than 50V-60V I wanted to discuss this. Since all my components are compatible with up to 100V (CA, Phaserunner), and since with higher voltage I can expose all the wiring to less intimidating currents - then wh...
by thunderstorm80
Sep 10 2016 12:35pm
Forum: Motor Technology
Topic: ezee motor + Phaserunner + 1000W limit obsolete?
Replies: 24
Views: 4506

Re: ezee motor + Phaserunner + 1000W limit obsolete?

I still think the magnetic losses are negligible compared with the I2R losses in our discussion. And I still disagree from a pure physic perspective: The mechanical load you talk about, is what causing the majority of input power. Since the motor is always giving a fixed maximum phase current (and t...
by thunderstorm80
Sep 08 2016 2:31pm
Forum: Motor Technology
Topic: ezee motor + Phaserunner + 1000W limit obsolete?
Replies: 24
Views: 4506

Re: ezee motor + Phaserunner + 1000W limit obsolete?

Grin's warranty excludes damage caused by overheating. They're not monitoring your power levels, but you can't send in a motor with the winding insulation burned off. They recommend power levels to avoid overheating issues, but these are continuous levels, and the warranty page specifically says "H...
by thunderstorm80
Sep 07 2016 10:50am
Forum: Motor Technology
Topic: ezee motor + Phaserunner + 1000W limit obsolete?
Replies: 24
Views: 4506

ezee motor + Phaserunner + 1000W limit obsolete?

Hi, I ran into this dilema with the new Phaserunner I hooked up to my ezee motor: Since the Phaserunner works by adjusting the phase-current, and if I set the max value to like 50A, and since my A123 can provide infinite amount of current - is there any more significance to input power limit? (which...
by thunderstorm80
Aug 21 2016 12:59pm
Forum: Motor Technology
Topic: ezee 250rc motor and ASI FOC ?
Replies: 0
Views: 237

ezee 250rc motor and ASI FOC ?

I plan to add a rear motor to my existing 9C+ 2706 to assist whenever needed in the high grades we have here. Since my existing system works on 79.2V (A123), and the ezee controller is up to 50V, will I be able to run it with the new FOC that Grin-Tech has developed? I ask, first of all, if the moto...
by thunderstorm80
Aug 21 2016 12:50pm
Forum: E-Bike Technical
Topic: BMS mystery - how does it actually work?
Replies: 17
Views: 2722

Re: BMS mystery - how does it actually work?

will your motor actually deliver 12amps to the battery? The amount of current the regen can produce is dependent on the battery pack internal resistance ( and voltage: state of charge), if its just a standard ebike motor ( nothing to powerful) and a not too big ( in ahr) battery pack ( say 10-12ahr...
by thunderstorm80
Aug 21 2016 1:27am
Forum: E-Bike Technical
Topic: BMS mystery - how does it actually work?
Replies: 17
Views: 2722

Re: BMS mystery - how does it actually work?

suggests that with LiFePO4 cells you only get a cycle count That explains it - A123 LiFePO4 doesn't suffer from cycle life reduction at all with regard to it's SOC. I have four of these for 5 years, and they are always charged up to 100%. Needless to say, they still hold almost the same capacity as...
by thunderstorm80
Aug 20 2016 2:38pm
Forum: E-Bike Technical
Topic: BMS mystery - how does it actually work?
Replies: 17
Views: 2722

Re: BMS mystery - how does it actually work?

Really? On his Satiator page, Justin clearly shows one of the Satiator's benefit of partial charge - You will get many more cycles if you do a 90% or even 80% charge - and it looks as way more total energy capacity than the percentage you cut off. He claims you will pay off the Satiator's cost by be...
by thunderstorm80
Aug 20 2016 7:35am
Forum: E-Bike Technical
Topic: BMS mystery - how does it actually work?
Replies: 17
Views: 2722

Re: BMS mystery - how does it actually work?

In many cases the lifetime watt-hours through the pack is nearly constant regardless of what you do. Short cycling allows more cycles but if the amp-hour total to battery wearout is similar, to what advantage? You're wrong: If you limit your usable range from 0-100% to 10%-90% you double the life-c...
by thunderstorm80
Aug 19 2016 8:39am
Forum: E-Bike Technical
Topic: BMS mystery - how does it actually work?
Replies: 17
Views: 2722

Re: BMS mystery - how does it actually work?

Most BMS circuits use N channel parallel FETs in the negative lead to control the power. Power FETs have an inherent body diode that parallels the FET in the opposite direction so they can only control current flowing in one direction, in the other direction the diode conducts so there is no contro...
by thunderstorm80
Aug 17 2016 6:22am
Forum: Motor Technology
Topic: Geared motor on tough off-road terrain - wrong choice?
Replies: 71
Views: 7021

Re: Geared motor on tough off-road terrain - wrong choice?

Look at serial drives. A small motor to the rear wheel on the left side. Look at Recumpence's builds. Or my mountain bike build. I couldn't find "serial drive" motor. You have to understand those kind of things bring too many unrelevant results on Google :) A direct link with an example would be so...
by thunderstorm80
Aug 17 2016 5:40am
Forum: Motor Technology
Topic: Geared motor on tough off-road terrain - wrong choice?
Replies: 71
Views: 7021

Re: Geared motor on tough off-road terrain - wrong choice?

If you want to keep all three chainrings there aren't too many (or any?) DIY mid drives. I'm maintaining all three front chainrings, and six or seven rear ratios by putting two hubmotors on a mountain bike. A DD in the rear and a geared in the front. With double torque it will climb like a tractor....
by thunderstorm80
Aug 16 2016 5:27pm
Forum: Motor Technology
Topic: Geared motor on tough off-road terrain - wrong choice?
Replies: 71
Views: 7021

Re: Geared motor on tough off-road terrain - wrong choice?

In the meantime I was learning about the BBS motors. It seems I will have to give up the triple crank on my MTB, and only use a single chain-ring if I pick that mid-drive motor. Are there other mid-drives that retain my original crankset? Maybe a direct-drive BB motor? Is there such thing? I don't ...
by thunderstorm80
Aug 16 2016 2:10pm
Forum: E-Bike Technical
Topic: BMS mystery - how does it actually work?
Replies: 17
Views: 2722

BMS mystery - how does it actually work?

Hi, I wanted to buy a battery pack from: http://em3ev.com/store/ They are very nice and seems very professional, but I couldn't get one thing right - Their BMS. Because I need regen, and quite powerful one, I was told their BMS can't accept more than 12A of charge. I offered to to buy two battery pa...