Might run the Ezip Trailz at 12V. Thoughts?

[bluegoatwoods]

I'm thinking of stepping down to 12 Volts on my Currie Ezip Trailz.

I really don't need 450 watts of power. I'm a strong pedal-er. It's my belief, correct me if I'm wrong, that the stock "battery" is really just a case that holds two 12 volt cells. (I probably won't use the actual cells in the case. Maybe something more like an ATV battery or two. Something unspillable, anyway) Imagine splitting these two cells apart and operating the bike at 225 watts. It would seem to me that I've just doubled my range, while carrying the same weight in batteries. Thinking about it a bit more, a properly protected motorcycle battery would probably be safe enough for a conservative rider like me while being light and inexpensive to replace.

The bike would have only half the torque, I'm thinking, that it does at 24 volts. But I would gladly trade that for doubled range.

Or am I missing something? Would the electronics, operated at half of the nominal voltage, somehow interfere and, perhaps, cut my torque by something like 90%. Things of that sort wouldn't be good. I don't suppose the electronics would get fried being under-volted, would they? An experiment along these lines would not likely damage the bike, would it?

I'd sure appreciate the thoughts of those who know a bit about this sort of thing. Thanks.

 

[spinningmagnets]

The controller likely has a Low-Voltage-Cutoff (LVC), so when using 24V, it will cut power to the motor when the battery gets low. I recently saw a 48V scooter that had a 42V LVC.

Also a certain amount of the system power is taken up just overcoming the losses of simply running the system. Cutting the voltage in half (if you modified the LVC in some way to allow this) would result in having about 1/4 of the power going to the wheel instead of half.

It sometimes seems easier to just hold the throttle completely down, instead of constantly adjusting it to keep the power where you may want it. To do that, you might add a resistor inline with the throttle wire. It is likely a 5V throttle. The controller sends 5V to the throttle, and by adjusting the throttle, a voltage between 0.2 and 5.0 returns to the controller. The controller uses that signal to decide how much power to send to the motor. Try a couple different resisitors till you find one that you like, they are dirt cheap.

If you don't own a $10 digital voltage meter, thay are very useful for a variety of different reasons, I'd get that first.

A resistor would restrict the signal to a partial throttle so you could hold the throttle all the way on, but only get half power, forcing you to pedal more. Just a thought, best of luck.

 

[DrkAngel]

Running an IZip at 12v would give you a top speed of 8mph, at 1/2 the normal torque. Except ... The low voltage cutoff of the controller will not allow any function.

 

[neptronix]

Hmm.. i cannot imagine an eZip going slower, lol.

I doubt the controller would work on half the voltage for one.
Your top speed would be cut in half, and it would be far faster to pedal.
Your range would also go down as a higher voltage system going slower means more range.
You could parallel the 12v batteries to get that range back.

But frankly the majority of the heft of that bike is the bulky frame, and the motor.

 

[dogman dan]

Could run it on an even lower wattage brushed controller I suppose. Like a 100w stand up scooter controller.

 

[bluegoatwoods]

So, the controller is likely to stand in my way, huh? That's too bad. I wonder if I could "outsmart" it using another, small & lightweight, 12 volt power source hooked in series with the main power. A diode or two would stop this circuit from trying to power the motor. I don't have a circuit in mind just yet, but I might be able to come up with one.

spinningmagnets; I do own a digital multimeter. I just wouldn't know how to use it for this purpose. I'll re-read your post and try to digest it. Then I'll likely come back with questions.

dogman; I don't understand controllers enough to work with your suggestion yet. But you've given me something to sink my teeth into. I'll try to learn a bit and see if that gets me where I want to go.

Thanks.

 

[TylerDurden]

Your range would also go down as a higher voltage system going slower means more range.

Really...??

 

[neptronix]

Your range would also go down as a higher voltage system going slower means more range.

Really...??

Taken out of context, that is confusing..
I think i misunderstood the OP in that he was talking about removing one battery.

Sentence afterwards talks about changing the batteries from a series to a parallel connection to get more range but a drastically lower speed.

 

[grindz145]

Don't kid yourself, those things are NOT 450w, they're more like 250W. Even with a nasty inductive spike it would be hard to see 450w.

 

[amberwolf]

The bike would have only half the torque, I'm thinking, that it does at 24 volts. But I would gladly trade that for doubled range.

You could just put a physical stop on the throttle so it can't go past half, and it will do nearly exactly the same thing that running at 12V would do (assuming you intend to parallel the two 12V batteries, instead of simply removing one).

There are some electronic things you could do to effectively do the same thing without physically altering the throttle's movement, but the stop is much easier.

 

[neptronix]

Amberwolf gives me an idear..

How about this:
Loosen the throttle and rotate it downwards.
That way, you can only twist it so far with your hand.

 

[amberwolf]

There ya go--that's even easier; wish I'd thought of it. :lol:

 

[wineboyrider]

Or just lock the throttle at 1/2 throttle and use the pedalec only option??

 

[DrkAngel]

Top speed would be 8mph!

 

[DrkAngel]

Use power assist on hills or getting up to speed, then pedal only?

 

[TylerDurden]

Loosen the throttle and rotate it downwards.
That way, you can only twist it so far with your hand.

There ya go--that's even easier; wish I'd thought of it. :lol:

Really????



@DrkAngel, the OP does not need much assist.

 

[neptronix]

Really????

 

[TylerDurden]

Really????

O_RLY-Quite.jpg

Maybe if his hand were glued to the grip.

 

[neptronix]

Maybe if his hand were glued to the grip.

Nah, you can make the starting angle awkward enough to make using the throttle more difficult.
I do this with my MAC setup because the controller is set to 35a and i only have nylon gears.. it's a ghetto way of regulating my amps until my controller programming cable comes :lol:

 

[DrkAngel]

Less throttle relates to less assist, however with 1/2 throttle, (12v) all assist peters out at about 8-9mph.
24v = some assist to 18mph. 15-16mph no pedal speed.
36v = some assist to 27mph. 22-23mph no pedal speed.

 

[TylerDurden]

Maybe if his hand were glued to the grip.

Nah, you can make the starting angle awkward enough to make using the throttle more difficult.

Not sure how you do that with a half or full grip throttle. Thumb throttle maybe.

@ DrkAngel:

Agree, half 12V would be very little. My understanding is the suggestions were 50% throttle range @ 24V, or 100% throttle range @ 12V.

Max P_out = ~225W

 

[DrkAngel]

Don't kid yourself, those things are NOT 450w, they're more like 250W. Even with a nasty inductive spike it would be hard to see 450w.

"Watts" are not electrical input watts. Watts are a measure of power output. 750 watts equals 1 Horse Power.

Most EZips-IZips have 450w motors, which equals 6/9th HP. Being a brush motor, input might be 600 electrical watts, or more. However, there is, also available a 250w version.

450w is generally rated comparable to the the output of a reasonably fit biker. My, faster speed geared, 70lb, Mountain Bike EZip, cruises comfortably at 20 mph. I would like see a typical biker pedal the same bike at a sustained 20 mph. Sounds comparable to 450w! ... ???

 

[dogman dan]

Just riding half throttle is truly the easy solution. When hypermiling, I found marking the throtte with a few notches helped me know exactly where 1/2 and 3/4 throttle are. Then you just match up the marks if you want to limit watts.

Re the controller, your stock controller is x watts, whatever that is. That happens because inside is a device that limits amps. I don't know the actual numbers, but say you have a 15 amp controller now. Replace with a 10 amp, and you'd have a max of about 250 watts on 24v. Replace with a 6 amp, and you'd have about 150 watts, and so on. The small stand up scooters have controllers as low as 4- 5 amps I think.

But it's easiest to just train yourself to ride half throttle. With a bit more experience, you'll find yourself able to hypermile better and better.

 

[DrkAngel]

Once again, 1/2 throttle will apply 1/2 the assist, but only up to about 8 mph. Above 8mph there will be no assist! The motor will turn but at slower than the wheel.

On the other hand, a lower amperage controller will supply less assist, all the way up to top speed, about 16-18mph. OEM EZip-IZip is 24v 25a. Oops, sorry ... 35a.

I heartily recommend the 16T upgrade. Raising assist speed into the 20-22mph range is well worth the $20!

https://www.endless-sphere.com/forums/viewtopic.php?f=3&t=25726

 

[bluegoatwoods]

Thanks, folks!

I'll keep on re-reading this thread to make sure I absorb everything. I'm already seeing interesting thoughts and ideas. Good manners would suggest that I thank individuals for these. But you are already becoming too numerous for that.

The mechanical throttle stop suggestions would seem to be a lot more simple than any electronic fixes. This would eliminate any need that I can see to step down to 12 volts anyway.