44 Magnum

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DrkAngel
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44 Magnum

Post by DrkAngel » Oct 07, 2011 8:37 am

Stay tuned for my 44 Magnum!

The Lipo packs I recycle, are nicely built in 3S, 11.1v, "bricks".
It has been bothersome adding 1S, to build 7S 25.9V and 10S 37V packs.
Fortunately, a 12S 44.4V pack charges nicely to 50.4V.
The 48V controllers, I've been eying, have low voltage cutoffs of 41V & 42V ...
42V / 12S = 3.5V, which is my personally recommended, optimal DOD (Depth Of Discharge)!
Test pack will use 2160mah cells, in a 12S 10P configuration. (.96kWh)
44.4V - 21.6ah
Which can be easily paired with Twin Sister Pack for 1.92kWh pack.
44.4V - 43.2ah
Yeah ... I stocked up on cells!


My initial use will be on my 24V EZips ...
Running a 24V motor at 44V might seem like a good way to burn up it up?
There are many stories of these motors being burnt up, running at 36V.
Some have gone to extravagant measures of, cooling, ventilation etc.

Well ... I do not propose this option as an uninformed or lightly considered manner.
I have run multiple bikes at 37V, for thousands of miles, with no problems.
My key to motor 'survival" is not additional cooling, it is prevention of heat production!
Full throttle draw at a dead stop is 30+ Amp, full throttle at top speed is 10- Amps.
Full throttle at 5mph might produce 80% waste heat and 20% usable power.
DC motors seem to have an efficiency range, this range moves - dependent on throttle position.
Throttle, "effectively", regulates the voltage to the motor, the "efficiency range" of the motor seems to be in the 50-80+% of top speed, nearing 80%+ efficiency & 20%- wasted heat.

With the EZip 24V:
Throttle % : Equiv. V : Max mph : Best Pwr
....25...........6V.......... 5....... 3-4 mph
....50...........12V.........10.......5-8 mph
....75...........18V.........15...... 7-12 mph
...100...........24V.........20......10-16 mph

With the EZip 44.4V:
Throttle % : Equiv. V : Max mph : Best Pwr
....14...........6V..........5.........3-4 mph
....27..........12V.........10.........5-8 mph
....40......... 18V..........15........7-12 mph
....45......... 24V..........20 .......10-16 mph
....67..........30V......... 25........13-19 mph
....81......... 36V..........30........15-24 mph
....90 .........40V..........35........18-30 mph
...100......... 44.4V.......39 **......20-35 mph

As long as the throttle is regulated and the motor kept in the efficiency groove, heat should be manageable.

24V full throttle at 5mph (80% wasted heat)
Should prove much more damaging than -
44.4V full throttle at 30 mph (20% wasted heat)
44.4V full throttle, @ 30mph, produces less than 1/2 the heat as 24V full throttle @ 5mph!

Moderate initial throttle, combined with pedal-assist, keeps my motors in the pink, (moderate temperature).

Personally, I have difficulty understanding eBikers that pump more and more amps into their motors.
2x the amps might produce 50% more low speed torque, but it also produces 300% of the damaging heat.
With only a slight, if any, increase in top speed.
But that might just be my frugal spirit being offended by the speed, sorry, power demons!

** "Max Mph" does not reflect wind resistance! Still ... 44.4V should produce 30++ mph!
37V provides 27mph, with pedal assist, past 30mph.
Image EZIP ENGINEERING 101 Image
Last edited by DrkAngel on May 01, 2012 8:02 am, edited 4 times in total.
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Re: 44 Magnum

Post by gogo » Oct 07, 2011 10:44 am

Ya, those stock Currie controllers probably let through 35A * 2.5 = 87.5A to the motor until you get to 40% of the no-load speed. The motors are rated at what, 24A continuous?

What would probably work well would be using a temperature gauge with a watt meter. Figure out the safe maximum operating temperature, and when you reach it start limiting the watts (via throttle) to the levels the motor will tolerate without raising the temperature.
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Re: 44 Magnum

Post by vanilla ice » Oct 07, 2011 11:44 am

Drilling the covers is pretty straight forward, if time consuming.. not what I'd call extravagant. When I used to ride my overvolted currie I did the same as you're saying. Move the throttle depending on speed. Low speed = low throttle. Worked fine. Like I've said, you can burn up these motors with stock voltage. Just have some mech empathy and I bet it would handle 44 or even 60 volts fine. Maybe I'll try 60 this weekend just for fun.

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Re: 44 Magnum

Post by 999zip999 » Oct 07, 2011 1:15 pm

Great info Dark Angle and would like to use it, if I could make myself. But some of use go down one step at a time and some take two steps at a time, and some just sit on the rail and sslide down. At a higher risk. I will try at 80%, but for how long and what cost to my heart ? Ride and let ride.

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Re: 44 Magnum

Post by neptronix » Oct 07, 2011 1:57 pm

44 volts nominal? you wild man, you. :mrgreen:
I hope nobody gets hurt.
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Re: 44 Magnum

Post by 999zip999 » Oct 07, 2011 3:14 pm

This is a izip with the chain drive rear motor ? Or the scooter ?

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Re: 44 Magnum

Post by DrkAngel » Oct 07, 2011 3:23 pm

30mph, maybe + a bit, is my EZip Trailz final goal.
The definition of a good driver-biker is that they blend smoothly with traffic.
For my local running about, 30 mph speed limit covers everything, for a several mile radius.
Anything beyond pedal assist capability, (+30mph-), I will relegate to my eMotorcycle project ...
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 44 Magnum

Post by 999zip999 » Oct 08, 2011 10:05 am

I find 28mph is a top real speed to go I find me going 33mph full all the time and keep telling myself with a little water out of the corner of my eye to take it to 80% as I did last night for bit till I found my wrist had twisted some how ? 22mph and you can still see the birds ect.

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Re: 44 Magnum

Post by DrkAngel » Oct 27, 2011 5:12 am

DrkAngel wrote:Stay tuned for my 44 Magnum!

The Lipo packs I recycle, are nicely built in 3S, 11.1v, "bricks".
It has been bothersome adding 1S, to build 7S 25.9V and 10S 37V packs.
Fortunately, a 12S 44.4V pack charges nicely to 50.4V.
The 48V controllers, I've been eying, have low voltage cutoffs of 41V & 42V ...
42V / 12S = 3.5V, which is my personally recommended, optimal DOD (Depth Of Discharge)!
Update: Optimal DOD revised to 3.6V (Li-ion - LiCo 18650 cells)
3.5V per cell, low voltage cut-off, should work nicely for 3.6V minimum, actual, discharge.

Test pack will use 2160mah cells, in a 12S 10P configuration. (.96kWh)
44.4V - 21.6ah
Which can be easily paired with Twin Sister Pack for 1.92kWh pack.
44.4V - 43.2ah
Yeah ... I stocked up on cells!


My initial use will be on my 24V EZips ...
Running a 24V motor at 44V might seem like a good way to burn up it up?
There are many stories of these motors being burnt up, running at 36V.
Some have gone to extravagant measures of, cooling, ventilation etc.

Well ... I do not propose this option as an uninformed or lightly considered manner.
I have run multiple bikes at 37V, for thousands of miles, with no problems.
My key to motor 'survival" is not additional cooling, it is prevention of heat production!
Full throttle draw at a dead stop is 30+ Amp, full throttle at top speed is 10- Amps.
Full throttle at 5mph might produce 80% waste heat and 20% usable power.
DC motors seem to have an efficiency range, this range moves - dependent on throttle position.
Throttle, "effectively", regulates the voltage to the motor, the "efficiency range" of the motor seems to be in the 50-80+% of top speed, nearing 80%+ efficiency & 20%- wasted heat.

With the EZip 24V:
Throttle % : Equiv. V : Max mph : Best Pwr
....25...........6V.......... 5....... 3-4 mph
....50...........12V.........10.......5-8 mph
....75...........18V.........15...... 7-12 mph
...100...........24V.........20......10-16 mph

With the EZip 44.4V:
Throttle % : Equiv. V : Max mph : Best Pwr
....14...........6V..........5.........3-4 mph
....27..........12V.........10.........5-8 mph
....40......... 18V..........15........7-12 mph
....45......... 24V..........20 .......10-16 mph
....67..........30V......... 25........13-19 mph
....81......... 36V..........30........15-24 mph
....90 .........40V..........35........18-30 mph
...100......... 44.4V.......39 **......20-35 mph

As long as the throttle is regulated and the motor kept in the efficiency groove, heat should be manageable.

24V full throttle at 5mph (80% wasted heat)
Should prove much more damaging than -
44.4V full throttle at 30 mph (20% wasted heat)
44.4V full throttle, @ 30mph, produces less than 1/2 the heat as 24V full throttle @ 5mph!

Moderate initial throttle, combined with pedal-assist, keeps my motors in the pink, (moderate temperature).

Personally, I have difficulty understanding eBikers that pump more and more amps into their motors.
2x the amps might produce 50% more low speed torque, but it also produces 300% of the damaging heat.
With only a slight, if any, increase in top speed.
But that might just be my frugal spirit being offended by the speed, sorry, power demons!

** "Max Mph" does not reflect wind resistance! Still ... 44.4V should produce 30++ mph!
37V provides 27mph, with pedal assist, past 30mph.
See the chart & graph for the mAh per 100th volt. - Homemade Battery Packs!
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 44 Magnum

Post by DrkAngel » Nov 15, 2011 4:45 pm

Got me some pieces-parts:

YiYun YK43B - about $75 w/ship
Hardcore 24-60V, brush, 1000 watt controller.
Water proof! Big, heavy - armored!
No frills, just power in, power out and Hall connection.
No over, or under volt cut offs.
Great testbed ...

Yi-Yun LB-37 - about $45 w/ship
48V 50amp 1500 watt, brush controller.
Light weight, small - fits as direct replacement in EZip rack!
95% conversion efficiency.
40.5V LV cut off

LB-37 is tagged as 44 Magnum fodder.
I will probably test it on one of my EZips, got a couple extra.
Still waiting on my 12ga spokes, supposedly shipped today.
Ordered enough to respoke 2 EZip rear wheels.
I intend on charging my 44 Magnum 12 cell Lipo pack at 49.2V (4.1V per cell), and discharging to 44.4V (3.7V per cell), with even massive voltage sag, 40.5V cut off, should allow my maximum recommended DOD.

Gotta be quick, need some road time, with it, before the snow sets in!

Plan on a 26Ah 44 Magnum LiPo pack ... darn, have to use a few of my good cells, all my previous LiPo builds were built from the non-perfect packs - seconds.
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 44 Magnum

Post by DrkAngel » Nov 22, 2011 10:42 pm

Homemade Battery Packs - Methods & materials for building your own battery packs. Image
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 44 Magnum

Post by RyanTo » Jun 18, 2012 6:32 pm

DrkAngel wrote:Got me some pieces-parts:
Yi-Yun LB-37 - about $45 w/ship
48V 50amp 1500 watt, brush controller.
Light weight, small - fits as direct replacement in EZip rack!
95% conversion efficiency.
40.5V LV cut off
Do you have a link of a place that sells these? I'm having no luck finding them..

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Re: 44 Magnum

Post by DrkAngel » Jun 18, 2012 6:47 pm

RyanTo wrote:
DrkAngel wrote:Got me some pieces-parts:
Yi-Yun LB-37 - about $45 w/ship
48V 50amp 1500 watt, brush controller.
Light weight, small - fits as direct replacement in EZip rack!
95% conversion efficiency.
40.5V LV cut off
Do you have a link of a place that sells these? I'm having no luck finding them..
48V Controllers
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 44 Magnum

Post by MattyCiii » Jun 18, 2012 7:02 pm

Interesting observations on power...

Image
You gotta tame the beast before you let it out of its cage.
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Re: 44 Magnum

Post by HypnoToad » Jun 18, 2012 10:29 pm

43aH is gonna give you a very good range, and should be nicer on the cells also as you'll probably never go below 50% charge unless you're doing a rather long trip. The joys of having a lot of cells. :mrgreen:

Also, to hit 30mph with pedal assist, is high gearing recommended?

I'm running 48T up front, and 11t smallest rear gear, and even so at around 20mph I was pedalling pretty fast. Maybe a 53T front sprocket is in order.

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Re: 44 Magnum

Post by RyanTo » Jun 19, 2012 12:24 am

DrkAngel wrote:
RyanTo wrote:
DrkAngel wrote:Got me some pieces-parts:
Yi-Yun LB-37 - about $45 w/ship
48V 50amp 1500 watt, brush controller.
Light weight, small - fits as direct replacement in EZip rack!
95% conversion efficiency.
40.5V LV cut off
Do you have a link of a place that sells these? I'm having no luck finding them..
48V Controllers
Cool! Do you know anyone who has tried it? I have a 12s 2p lipo pack so I think I might try it. Just be easy on the throttle starting out and up hills I suppose..

I have the 250watt motor on a ezip skyline. I'm not completely sure the difference from the trailz motor.

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Re: 44 Magnum

Post by DrkAngel » Sep 22, 2012 9:05 am

HypnoToad wrote: ... to hit 30mph with pedal assist, is high gearing recommended?

I'm running 48T up front, and 11t smallest rear gear, and even so at around 20mph I was pedalling pretty fast. Maybe a 53T front sprocket is in order.
60 rpm is considered a "casual" pedal rate.
The max sustainable - efficient - effective = optimal pedal rate is about 90 rpm.

With my Haro these pedal rates produce:
700c = 28" wheels - My Haro Express Deluxe
(60rpm x 60min) x (48T/11T) x (28" x 3.14) / (12" x 5280') = 21.80mph
(90rpm x 60min) x (48T/11T) x (28" x 3.14) / (12" x 5280') = 32.69mph

See - Sprocket Ratio = Pedal Assist MPH

I have pushed - trained myself towards maintaining the optimal 90 rpm pedal rate.

A less forceful - higher pedal rate workout is considered better for:
Cardio-vascular
Fat burning
Muscle durability vs mass ratio development
other factors also? ... haven't had my coffee yet!

see - 700C 8 speed eZipped for 30mph+
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

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Re: 44 Magnum

Post by docnjoj » Sep 23, 2012 7:22 am

The higher pedal cadence also helps reduce knee problems.
otherDoc
E-bike stable at our house

Steintrike Mad Max full suspension trike rear Cute 100H going on: Whoops, Cute wheel broke but I fixed it.
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2x16000 Multisport from HK now gone as they died after 2 years
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Re: 44 Magnum

Post by DrkAngel » Nov 16, 2013 9:16 am

Winter ...
Time to play.
Building 33.3V Li-ion & LiPo for my Heavy Cruiser and Winter bikes.
Finally ready to build 44.4 MAGNUM.

This graph matches the 25.9V performance on my target eBike almost precisely.
So the 44.4V projected performance should be reasonably accurate ... ?
44.4Magnum 1.jpg
44.4Magnum 1.jpg (126.66 KiB) Viewed 2263 times
http://ebike.ca/simulator/

Please notice that I limited the controller to 22.5A!
This is specifically to limit motor output to a "legal" 750w to reduce wasteful-damaging heat at, severely inefficient, lower speeds.
Nice bonus is that motor output steadily increases till top speed ... giving more power where you need it!

Yeah ... motor only 30mph attained! .. 8)
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

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