2500w / 100Ah Lifepo4 / KLS4812S controller e-scooter configuration

[NC50]

Hi,

I could use some help with my e-scooter configuration. It,s a dutch model ''Novox C50'' with 2500w motor.
The battery is a 100ah 48v lifepo4 with bms, controller used is a Kelly KLS4812S (https://www.kellycontrollers.eu/kls4812s.

I have no experience with setting a controller up.

I'd like fluent acceleration and a top speed of ~33 Km/h GPS. I prefer long action radius and battery longevity over speed and acceleration.

Had someone help me with setting the motor poles but I'm encountering some issues:

1) speed goes up to 41 KM/h (scooter dashboard speed) and drops down after a few seconds to 34-35~ Km/h, then speed goes up to 37 Km/h stays like that for ~15 sec, then speed goes down to 35 Km/h again, goes up to 37 Km/h and stays that way. Every time after releasing throttle this process repeats itself.

2) regen sometimes makes my scooter turn off, battery bms protection? RLS_TPS Brk% was set at 10, now lowered to 5 but haven't tested yet.


Can someone give me advice to optimise controller settings?

 

[flippy]

first focus on the bms. what limits do you have on that? a shutdown is basically always a bms that shuts the party down due to overvoltage during regen or overcurrent during acceleration. change settings on your bms to prevent a shutdown.

does the speed hunting happen during driving or with the wheel up in the air?

generally the overshooting happens when the accelleration is too high and it wants to ease out instead of hitting a brick wall. that would be bad.

set up the regen so you can drive without touching the regular brake. also use neutral regen, not the brake lever regen.
set the brake level regen higher then neutral braking. that way you have 2 settings for regen. one just by coasting and if you need more you tap the brake lever.

 

[NC50]

first focus on the bms. what limits do you have on that? a shutdown is basically always a bms that shuts the party down due to overvoltage during regen or overcurrent during acceleration. change settings on your bms to prevent a shutdown.

does the speed hunting happen during driving or with the wheel up in the air?

generally the overshooting happens when the accelleration is too high and it wants to ease out instead of hitting a brick wall. that would be bad.

set up the regen so you can drive without touching the regular brake. also use neutral regen, not the brake lever regen.
set the brake level regen higher then neutral braking. that way you have 2 settings for regen. one just by coasting and if you need more you tap the brake lever.

I'll ask M to unlock the bms settings with his password so i can show you a screenshot of the settings. I havent touched bms settings because it is locked.

The speed hunting happens while during driving while seated.

Which values should I use for neutral and brake lever regen?

Anyways, the regen is causing my bms to shut off, yesterday i had 3 stops during a 7km ride...very annoying. I guess as long the bms problem isnt fixed regen brake is huge nuisance

 

[flippy]

turn the regen off until the bms settings are changed.

the speed hunting comes from the kelly not wanting to do the brick wall style that sevcon does and it just tapers off the acceleration. that jo-jo's a bit until the speed is stable. its mainly due to putting high voltage and currents in a motor that is forced to run at low speeds.
you hit the artifical limits way too hard before you get to the "natural" limits of voltage for example.

best thing you can do is reduce trottle when you get up to speed. when you hit 35 you can hold the trottle open again.

dont worry about getting a ticket, they have to wait until the speed is stable so you dont get a ticket.

 

[NC50]

turn the regen off until the bms settings are changed.

the speed hunting comes from the kelly not wanting to do the brick wall style that sevcon does and it just tapers off the acceleration. that jo-jo's a bit until the speed is stable. its mainly due to putting high voltage and currents in a motor that is forced to run at low speeds.
you hit the artifical limits way too hard before you get to the "natural" limits of voltage for example.

best thing you can do is reduce trottle when you get up to speed. when you hit 35 you can hold the trottle open again.

dont worry about getting a ticket, they have to wait until the speed is stable so you dont get a ticket.

>its mainly due to putting high voltage and currents in a motor that is forced to run at low speeds.
you hit the artifical limits way too hard before you get to the "natural" limits of voltage for example.


Is it possible to change settings in the controller to make this jojo effect less noticeable?

Speed is varying between 45 km/h and 29km/h (dashboard speed) at the moment and it's kinda annoying, speed stabilises (but still hunting) between 35-38 km/ when holding full throttle.

bms screenshots:

 

[NC50]

Would be nice if I could use regen function. Any ideas?

 

[NC50]

Could it be that this bms is not compatible with regen braking? That'd suck because then I have to look for a new bms and get someone to install it for me.

 

[flippy]

no, you need to either stop charging at 4V or raise the upper voltage limit that the bms engages at. so 4.3V or higher so the battery can absorb the power you put back in during regen.

this is only an issue when you are fully charged. once you have driven a bit the problem will go away.

 

[NC50]

no, you need to either stop charging at 4V or raise the upper voltage limit that the bms engages at. so 4.3V or higher so the battery can absorb the power you put back in during regen.

this is only an issue when you are fully charged. once you have driven a bit the problem will go away.

I forgot to upload a screenshot of the bms failure

' Protection (discharge short circuit) (2s)'

I talked with M and he said he was worried about raising the upper voltage limit because the bms reports a short circuit.

Any thoughts on this?

>this is only an issue when you are fully charged. once you have driven a bit the problem will go away

The bms protection also kicked in when the battery was around 80% full, so what's going on there?

 

[flippy]

max discharge current is set to 100A. that needs to be increased to the maximum.

 

[NC50]

max discharge current is set to 100A. that needs to be increased to the maximum.

I can't increase the max discharge current, when applying the setting the app reports 'command send failure'.

Is this setting normally adjustable or do I have to change other values before I can raise this?

Any ideas?