Is E-Joe Jade 750 Low Voltage Cutoff Adjustable?

[Johnsinski]

Hello, I bought a used E-Joe Jade 750 with no battery. Since I do alot of RC hobby stuff I thought I'd make my own. I used 16 Headway 38120 LiFePo4 8000 mAh cells. I've got a Daly BMS on it and just charge it with a 60V power supply. It works but I don't think I'm getting much mileage (distance) out of it.

On mixed terrain (mostly flat, lightly pedaling), it kicked out at around 17 miles and the Daly BMS app said the battery was still at 85% charge (don't remember the voltage, probably around 51 or so, it starts out at about 55v full charge). I think the controller on the bike might be kicking out due to low voltage, but that seems ridiculously early. I would think the battery should be dead at around 40 volts (2.5x16). A regular 13 cell LiPo pack would be dead at 39v (3x13).

Not that I need to go more than 17 miles, but something doesn't seem right.

Is there a way to adjust the low voltage cut off? I assume the "voltage adjustment" in the menu on the bike is just for the graphics display. When it kicked out it had 3 out of 5 bars on the display. Has anybody ever "flashed" a controller to change the low voltage cut off?

I'm not super familiar with e-bikes.

Thanks,
John

 

[PCeBiker]

I used 16 Headway 38120 LiFePo4 8000 mAh cells.
,.. it kicked out at around 17 miles

That doesn't sound too far out of line to me.
The original battery was 48V 14AH and had a Maximum range of 45 miles.
You have an ~48V 8AH battery taking you 17 miles.

Pulling 1000 Watts from a relatively small battery can cause a Huge voltage sag but 11 or so volts does sound excessive.
Perhaps not for LiFePo4 cells?

,.. When it kicked out it had 3 out of 5 bars on the display.

The bar graph on my display doesn't show less than 4 out of 4 bars until my battery is at ~45.5V. (about 25% remaining)
Full charge is 54.6V and my controller cuts out at 40V, but with voltage sag, my controller will start to cut out when my battery is at ~43V if I'm drawing ~750 Watts from my 25AH battery.

Is there a way to adjust the low voltage cut off? I assume the "voltage adjustment" in the menu on the bike is just for the graphics display.

The voltage adjustment on my display adjusts the speed of voltage reading.
I set it to "0" (as in "real time"), so there's no damping and I can see the voltage sag better.

Has anybody ever "flashed" a controller to change the low voltage cut off?

I can adjust my low voltage cut off with my display. You might be able to with yours?
Many ebikes have a password to enter that gets you into the advanced settings.

 

[PCeBiker]

Your Display is listed as this,..

LCD Display: KD-58C (Pedal Assist Level, Battery Level, Speedometer)

I found this KD58C manual.
It may be the same as yours?

https://www.reidbikes.com/wp-content/uploads/2023/09/Reid-KD58C-Display-Manual-compressed.pdf

Looks like you can adjust your bargraph voltage settings and your controller maximum current between 7 and 25 Amps.

Turning down your maximum current will help reduce the Voltage sag and extend your range.

 

[PCeBiker]

I found this thread about your ebike,..
Apparently it goes like Hell.

I think my New e-JOE Bike is way faster

I just unboxed the e-JOE JADE 750 Comfort Cruiser .It can go up to 34 mph but with me 210 lb easily going 28+ on throttle only . I think its kind of too fast for ebike

forums.electricbikereview.com

 

[Johnsinski]

Oh, duh. The manual shows how to get to more settings. It doesn't have a low voltage cut off though.

The cells are supposed to be 200Amp capable. Next time I ride I'll see if I can read the voltage sag off the Daly BMS, I don't think it should be much. But then maybe the voltage reading is not accurate on the Daly BMS.

I guess the 17 miles range does seem within the ball park. Maybe it's much ado about nothing.

Oh, now that I am looking at the Daly BMS app, at full charge (54.3v 100% SOC) it says I have 50.0 Ah left.

I was able to change a default cell capacity in the app from 50.0 Ah to 8.0 Ah. Note that (50Ah-8Ah)/50Ah is 84% SOC. So I'm guessing that's what my problem was.

Can't wait to try it now, I'll report back.

Thanks

 

[Johnsinski]

As far as going like hell, meh. I did get the BMS app to read as high as 700W though, going full throttle up hills. I think it's speed limited to 25MPH, but that can be changed.

 

[Johnsinski]

Yea, things are making more sense now, the BMS app is now showing the battery capacity go down much faster and is more in sync with what I would expect. I'll still have to adjust the bar graph voltages on the bikes display a bit.

At a 700 W load the voltage drop is only about 1V.

Thanks