hello from scotland need some lcd8h setup help

[hansolo_uk]

hi i have a mario ebike with 750w bafang rear hub motor and had to replace the cable and accidently shorted controller pcb to chassis when i forgot to remove battery DOH. n given the difficulty finding a suitable new controller with the 9 pin hex controller i went with a rinsun one https://www.risunmotor.co.uk/produc...s-dc-controller-support-regenerative-function and lcd 8h and changed connectors. from higo ones. after some wiring issues of pas n throttle wiring i swapped n matched the pinouts and got it running yesterday and hopefully get some good weather to test soon, but anyone any tips on lcd8h settings (want throttle always on)

cheers.

 

[harryS]

On my LCD3's, P4=1 and C4=4 give me throttle always on. I've only got that set on one bike. I prefer it off in peda; assist 0.

 

[hansolo_uk]

now having a range issue where the display rapidly goes from 52vish to 40v and shuts off after only a few min of riding, yet if i reseat the battery it reads 48v ish on screen and on battery indicator still full 1red 3green !!! and does same again and again cutting off and reseat says still above 40v !!! after maybe 6 times n iv come home, battery still says 1red 2green at least.

is there a way to permanently disable the lcd8h displays cutoff (iv tried real time and smart V settings) on the lcd8h, or is there a cheap display like lcd880 i can fit that doesnt do the low v cutoff, but allows spped setting over 15mph ?

thanks for assistance hoping to ride more once fixed.

 

[PCeBiker]

You can turn down the low voltage cutoff to 38 volts using C12=0

I think that you've got a battery that is wearing out or has unbalanced cells.

I have my 25 amp controller turned down to half and also have C4=4 and turned down to 20% for throttle gear 1, so only 2.5 amps in first gear.

Even with everything turned way down, my controller starts cutting out when I hit 42 volts because of voltage sag bringing down the voltage down to 40 volts.

If you are pulling way more power from your battery, your voltage sag may be as high as 4 or more volts, especially if you have unbalanced cells.

If you used to get a lot further on a charge, then that suggests that your battery is wearing out.

PS,.. You don't have to remove and reinsert the battery.
I just shut off my display and turn it back on. That is enough time for the voltage to bounce back and the controller won't cut out.

I can do this while coasting and get the ebike restarted before I come to a stop.

 

[hansolo_uk]

what setting is for turning down controller ?

I have my 25 amp controller turned down to half

 

[PCeBiker]

what setting is for turning down controller ?

C5=3 cuts the power in half.

Limiting your power output will help keep your controller from cutting out, but you'll be slower with less acceleration.

I will try to find the link to the manual for the LCD8H for you.

 

[PCeBiker]

I think that this link will work,..

KT-LCD8H-1-0.pdf

drive.google.com

 

[harryS]

Got a bad feeling about this, Hansolo, Your battery is unbalanced. That means one or more of thecell groups is stuck near its low voltage cutoff, while the other groups are at high charge. The batrery BMS is doing this, not the bikes controller, because you're still at half charge when the display comes back on.

Sure, you could bypass the BMS and run the cells down lower, but that's how you get a fire. I suspect a lot of people in NYC do that, trying to keep their delivery bikes running, hence th distressing number of battery foires in that city.

 

[PCeBiker]

I know that with some battery/BMS combinations, you can "force a balance" by leaving the charger connected to the battery for a few hours after the light turns green on the charger.
Some batteries take 12 hours to balance.

The BMS will limit the voltage of each cell group to 4.21 volts and any cells/cell groups that are over discharged can trickle charge up to 4.21 volts to become fully charged.

My owners manual says that my battery will be fully charged within 7 hours, but you should unplug the charger by 14 hours.

BE VERY CAREFUL IF YOU DO THIS.
Charge your battery in a safe place and keep an eye on it.
Watch for any smoke or smell and any excessive heat.

It's worth a try, just be careful.

You might be able to bring your battery back to life.