EVD Modes

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whome
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EVD Modes

I noticed, and have read on here about situations where the EVD seems to have less power than normal. I have experienced this myself, and found, as posted, that turning the EVD off and back on resets it to full power.

Is there a known way to get the EVD in this mode. I would like to be able to set it to a lower power setting or "economy" as it might be called on the XM bikes, so that a beginner can try out the EVD for a ride.

Has anyone found a way to consistently get the EVD in this low power mode?

Also has anyone tried replacing the throttle or tweaking anything to get more control when engaging the throttle. It seems to only work in one area on my throttle and is more or less on/off with little variance of power.

Thanks,

Whome

dexion
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Re: EVD Modes

I have an evd 60ah lithium version. I havent seen any low power mode yet (350 miles on it so far and 1 weekish of ownership.) I do however have a few observations. It seems like shutting off and back on works for other situations as well. A few times my 12 volt system stopped working all of the sudden in a ride. I had to shut off the key and then back on after 30 seconds to have it re-enable the 12volt system (im waiting to see if rmartin has any ideas why this would happen but its not really much more than an annoyance if a quick restart fixes it.) Ive checked for lose wires and a bad/lose fuse but I have found nothing amiss. So it seems there is some sort of self test upon startup and some form of safety as well if something is awry it will disable/low power the problem. So following that train of logic you could have an issue that the controller is protecting agains. Overheat/over/under volt are the ones that spring to mins. It may be possible to identify and fake one of those three issues via a logic board/switch (sorry not an electrical engineer) and trick the controller into low powring because it thinks theres an issue (not saying its a good idea however.) But you may actually have some issue that is causing the low power condition you may want to look into fixing first. My throttle works as expected. Very easy to feed in what power I want to feed in and start slowly sorry I cant help with that BUT perhaps those 2 issues are one and the same for you (low power/poor throtle response) perhaps its nothing more than a bad throttle position sensor buggering up the whole mix.
dex

MikeB
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Re: EVD Modes

My EVD's throttle was very sensitive, the difference between full power and off was a small movement, perhaps 1/8 turn. It was more than on/off, but only if you carefully controlled your wrist position. I got used to the short control range after driving for a while, but always had to re-adjust after riding my gas scooter. I think the bike would be improved with a throttle that had a longer motion.

My electric vehicle: CuMoCo C130 scooter.

whome
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Re: EVD Modes

That's the problem. You have this huge amount of turn on the throttle, but all of the sensitivity is jammed together in the middle.

If anyone knows of a better throttle piece available, please send me a link.

Thanks,

Whome

antiscab
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Re: EVD Modes

the throttle issue sounds more like a controller problem, rather than the throttle itself.

There are two things at work here:

1) The throttle sends a 0-5v signal to the controller.
in reality, the signal may only be 0.5-4.5v, and another throttle may only be 0.9-4.9v
so in the controller an input of 1v or less = 0 throttle, and 4v or more = max throttle.
theres not alot that can be done about this, though it is the same for all bikes.

2) just about every controller i have come across is analogue.
of these, almost all use the throttle input to set the power stage duty cycle directly. (actually in this case for a 3-phase controller its called modulation index)
this means your throttle is directly affecting output voltage (proportional to speed), rather than output current which is proportional to torque/acceleration
the controller has an output current limit that cuts in if the applied output voltage would cause the current to get too high.

in practise this means a throttle position of 1/8 applies a high enough voltage to put the controller into motorside current limit at low speed.
as speed increases, higher and higher voltage is needed to get the controller into current limit, so more of the throttle is usable.

changing to a controller that gives the throttle proportional control over motor side current will give a more natural throttle response.
for 3-phase BLDC/ permagnet motors, kelly controllers are the only ones i know of that do this.

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst 2 x TC Charger & MC
conversion

whome
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Re: EVD Modes

I'm fairly certain it is the throttle. As I stated above there is some control. It is not just on and off, but if you didn't take some time to play with it some, you might miss the small difference between off, low and hi. I cannot detect more than two positions of power on throttle.

I have figured out how to get the EVD into the lower power setting mode at will. If you twist the throttle a little when turning it on, it will have a significantly reduced acceleration and speed. To get it out, just turn off and turn back on normally.

Whome

itachi1
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Re: EVD Modes

Does anyone know a method for making the throttle "stiffer?"

Coming from a 50cc scooter, the throttle on that was extremely mushy and either due to the crappy engine or nature of ICE, you actually had a great deal of reaction time between the throttle movement and speed push. I believe that the difference is that on an ICE, you're changing the amount of acceleration, while on an electric throttle, your position represents a motor speed target. I've found that it is extremely difficult to keep a consistent speed with the current throttle, and have gotten the start of a stiff wrist while trying. With the throttle at a certain point, once the bike reaches the speed you asked for, power to the motor cuts, then starts up again, then cuts, etc. Even a bump in the road has made the motor "strobe" like this.

So I would love for a lighter springback to zero and a mushier movement with more resistance--more like a tuning dial than the volume control it's currently set at.

Iccarus
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Re: EVD Modes

I have an XM3500li and I've noticed that running it at higher voltage seems to smooth the throttle some. I think they have the same controller as the EVD. A kelly controller is nice though. I have one on another 3500li and hooked up regen via another analog thumb throttle. It works great and I hardly need the disc brakes anymore...but they are there if you need them. I'm averaging 7% range gain from regen. 28 40AH cells =57mph

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

Spearo
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Re: EVD Modes

Anyone having trouble with an EVD hub motor overheating? Mine did and I replaced the motor but it still does. Whether I run it at 72 or 60 volts it is the same outcome - run between three and seven miles and the thing shuts down with a really hot (to the touch) motor.

Could the controller be the culprit? If I switch to a Kelly controller, which one should I get?

EVD VRLA converted to 72V

TimWms
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Re: EVD Modes

I asked about a possible "economy mode" last time I talked to Randall at RMartin Bikes. He tells me this is not really a low power mode - it is the controller out of sync with the motor, and happens on most all brushless motors at some time or another. So this mode probably uses more power giving less performance. Just switch off and switch back on to reset.

Tim Williams
Electric Motor Scooter - 2008 EVD 3000W

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