48v Ping & eZee hub conversion... How much is too much?

[Rob Melektau]

I bought an eZee front hub conversion kit without the battery and got a Ping 48v 20a LiFePo4 instead primarily to give myself a longer range. (I commute 20+ km each way)
I realize that I'm riding on the outside edge of what this motor is designed for, so...
The specs on the website say that at 48v the motor is rated 550w, and the 20amp controller is capable of dealing with 60v max. The battery is currently averaging 52v+/- under load, and just around 60v when fresh off the charger. I also bought the Cycle Analyst when I baught the motor knowing that I might have to tune the system down a bit. What do you think?

Right now I'll cruise at 35km/hr @ 400w and flat out 40+ km.hr @600w or so. A couple of times while going uphill I've gone to just over 1000w, but on a steeper grade I'll maintain 750-900w for 3 or 4 minutes at a time. Is this too much for this motor and or its 20 amp stock controller?
Yesterday I went up a fairly steep grade, and peddled at a light/comfortable rate, 3/4 throttle at 800w for 3-4 minutes. I immediately pulled over and felt the hub on both sides as well as the controller, the hub was maybe a couple of degrees over ambient, and the controller was cool to the touch. So it doesn't seem like I'm overtaxing it, but I'm still concerned...

Here are the stats from that ride.

Note: The first image was taken after charging and sitting overnight. Therefore the higher voltage. Plus it seems I caught the screen as it was changing display. Distance should read 29.83 km. The rest of the images were taken just after the ride.

 

[docnjoj]

I average 25 wh/mi on my 20amp 48 volt Ping and Bafang with similar Watts. I think the E-zee is a stronger, better motor, so I think your use is very appropriate! Drive on!
Also you are only using 50% DOD, so that battery should last a long time!
otherdoc

 

[snowranger]

Why is Amax over 30? That implies over 1500 watts.

 

[Rob Melektau]

Why is Amax over 30? That implies over 1500 watts.

I have no idea. The highest I saw was around 1060w and immediately backed right off.

Could it have something to do with the volts being so high? I'm pretty sure I didn't do 1500w!

 

[snowranger]

If you are peaking at 1000 watts, you should be okay then. I had gear wear problems at 1300 watts on my bmc hub.

 

[Ypedal]

The " Max Amps " value is normal, it's just a fraction of a second ( usually on startup ) and nothing to worry about.

600 to 800w continuous is ok imo as long as it's not on/off/on/off/on/off pulsing of the throttle.. let it hook up and stay on it smoothly, 1000w is pushing it, this is where you should back off the throttle and pedal a bit more hehe..

I managed to spin the ring gear on one of my eZee bikes, see:

http://www.ypedal.com/ezee.htm

It has been running great since the repair however, it's my " All Weather bike "

 

[Rob Melektau]

Thanks, thats put my mind a bit more at ease. To tell you the truth, I've been concerned about gear wear considering its nylon planetary gears, so I try and be as easy as I can with smooth acceleration and peddling to reduce over loading of the system.

I managed to spin the ring gear on one of my eZee bikes, see:

http://www.ypedal.com/ezee.htm

Well, if I ever DO wear out something, I know who to call

So, overall what do you think about the 14w/km? Reasonable?

 

[Ypedal]

14wh/km sounds right for the conditions you describe and at 48v.

On 36v with a puny 36v 6ah pack made from Konion cells ( light weight !! ) i get average 8 to 10 wh/km pedaling nice and eZee.. !

 

[el_walto]

I run my ezee hub/ controller / ping 48V 16Ah battery with the same setup as you. It pulls 900+Watts consistently up hills. The motor does not get hot, the controller does gets too hot to touch for more than 10 seconds, so you must mount it where it gets maximum airflow. I have 1200Km on my setup with no problems(yet)

 

[greydust]

Does the CA measure current draw from the battery to controller or from controller to motor? If it's the former, you're always going to see current figures above what the motor is actually doing (since the controller uses some energy to operate, some is wasted as heat, etc)

 

[GrayKard]

Does the CA measure current draw from the battery to controller or from controller to motor? If it's the former, you're always going to see current figures above what the motor is actually doing (since the controller uses some energy to operate, some is wasted as heat, etc)

CA measures between battery and controller. I only remember reading about 1 custom setup on here that measured the phase currents to use in his custom controller setup. Don't recall the user name or thread but I think I read it in the Ebke tech section.

Gary

 

[dogman dan]

No worries. Your ezee controller is well matched to the capabilites of the motor. As long as you are averaging 800w or less over the whole ride, it's very unlikely that you are going to melt it down.

It could be possible, but it would take an extreme ride. Hard trail riding with really steep hills could do it. Or pehaps a long ride in the rocky mountians in hot weather. If you are riding a hill so steep the motor slows below 10 mph, then you might want to keep that climb short. Short as in, don't keep riding for 30 min up such a slope. Or don't do it over and over.

Anything less that 10% grades should be no problem for that system, but if you have a hill slowing you down, a few brisk pedals would be best, to keep the speed a bit higher, which lets the motor work with less heat.

 

[Diamondback]

your set-up is pretty much exactly the same as mine, except i went for the 15A ping 48V.

i have the current limit on the CA set at 15A.
this still allows peaks of just over 1000W (on the ca screen) and then it quickly settles back to around 750W or so.
i have almost 2000km on mine now, and have had zero problems with the reliability of the motor or controller.

i still see peaks of around 30A, but as others have stated, these are transients usually for only seconds while starting out.
i usually pedal up a little before i get on the throttle, this helps limit high current draw, and helps to increase range.

i like to pedal a lot, and can usually get 6wh per km sometimes even less.
i did an 81km ride on just over 9ah.

my work commute is 34km round trip, and i usually get home having used about 7ah.

it's a very reliable combination.

Jason.

 

[SamTexas]

i like to pedal a lot, and can usually get 6wh per km sometimes even less.

I'm curious. Can you post a complete CA data set for one of your typical longish ride? Distance, average speed, wh/km.

 

[Diamondback]

sure can.

average speed was a little low (i was riding with some unpowered friends)



these are more typical for me.. (the below is a work commute run approx 34km, riding alone)

Jason.

 

[SamTexas]

Thanks. The second data set is complete. The average speed is missing from the first data set.

 

[Diamondback]

that's why i included the GPS log from that ride.

the first set was at 16km/h average speed.

Jason.

 

[SamTexas]

Ok, thanks.