Kelly Controller setting at low battery

basement

100 µW
Joined
Nov 10, 2019
Messages
7
HI All,
my vespa conversion is done, and very pleased with the result.
It rides better than before. I have a 60V battery and a KLS-7230n controller on a 3Kw 205 motor.
Top speed is about 58kmh, thought it be a bit more but in the end, that's fast enough.
I love the acceleration.
The problem that occurs now, is that when I approach the last third of the battery I can not accelerate anymore (or at least not full throttle) before the BMS shuts down the battery (in a protection mode.)
I draw too many amps I guess... so what setting do I lower on the Kelly Controller to avoid that? without loosing all my acceleration power when the battery is full.
or is there a way to reduce amps draw in relation to the battery voltage?
thanks for your reactions .
All the best,
 
Thank you for your reply.
Do you mean Battery low voltage?
I've set the low voltage on 48V as the 60V battery is a 16s the low voltage point ( as described by the manufacturer is 43,5V)
So I need to raise that number to 50V? will I not loose a lot of battery capacity?
Thank you
 
so little update :
even setting the lower limit to 52V did not change a thing.
Only by reducing the the battery current limit percentage to 30% and thus reducing the acceleration even more I manage to keep the engine running while accelerating at lower battery voltages.
is there no way to couple the battery current limit to the SOC of the battery?
 
Not without a far more advanced controller. What you really need is a larger battery or one with cells that can deliver more amps.

The 2nd option is to utilize the 3 speed option on the KLS. Use the high speed setting for 100% amp output when battery is fully charged or at 72v. Then switch to mid speed (settings adjusted to 50% amp output) when the battery is around 60% or 62v , then when the battery is down to 30% or 56v, switch to the low speed and set amp output to 25%. Obviously adjust amps to suit your needs but.... it is possible with your KLS.

You get what you want but it wont be automatic. Using something like an Arduino, you could develop a program to monitor your battery voltage and control the 3 speed switch automatically.
 
2WheelsMovesTheSoul said:
Not without a far more advanced controller. What you really need is a larger battery or one with cells that can deliver more amps.

The 2nd option is to utilize the 3 speed option on the KLS. Use the high speed setting for 100% amp output when battery is fully charged or at 72v. Then switch to mid speed (settings adjusted to 50% amp output) when the battery is around 60% or 62v , then when the battery is down to 30% or 56v, switch to the low speed and set amp output to 25%. Obviously adjust amps to suit your needs but.... it is possible with your KLS.

You get what you want but it wont be automatic. Using something like an Arduino, you could develop a program to monitor your battery voltage and control the 3 speed switch automatically.

Edit: FYI: the 3 speed option on the KLS is output current based, not wheel or motor speed based.
 
thank you for your reply,
it's a cumbersome workaround, but yes this might do the trick, thanks
 
2WheelsMovesTheSoul said:
Edit: FYI: the 3 speed option on the KLS is output current based, not wheel or motor speed based.

Hello 2Wheels!

Just to clarify this, does it really mean that using the speed switch will also change the current draw?
I am having the same issue with my KLS4812S, and it's really bugging me a lot. I am riding a 48v scooter and have adjusted the battery current setting to draw a max. of 35A from the battery, and a 2-speed selector using the medium/high speed function of the controller. But when shifting to high speed, it starts to draw about 45A from the battery, and that's just too much for my old lazy battery. I have somewhat come to the conclusion that the max. battery current setting is directly related to the phase voltage, so using the high speed switch and thereby also increasing phase voltage, will also yield a higher phase current and battery current. Am i on track here or?? Where did you came across the info about the speed switch being current based, because i have been thinking the same but unable to find any useful info anywhere.

Best regards
 
That is how Kelly controllers are, it says it right in every manual. Not sure if there is an easy fix

Monitoring battery voltage. It will stop driving if the battery voltage is too high and it will
progressively cut back motor drive power as battery voltage drops until it cuts out
altogether at the preset “Low Battery Voltage” setting
 
Ampster said:
2WheelsMovesTheSoul said:
Edit: FYI: the 3 speed option on the KLS is output current based, not wheel or motor speed based.

Hello 2Wheels!

Just to clarify this, does it really mean that using the speed switch will also change the current draw?
I am having the same issue with my KLS4812S, and it's really bugging me a lot. I am riding a 48v scooter and have adjusted the battery current setting to draw a max. of 35A from the battery, and a 2-speed selector using the medium/high speed function of the controller. But when shifting to high speed, it starts to draw about 45A from the battery, and that's just too much for my old lazy battery. I have somewhat come to the conclusion that the max. battery current setting is directly related to the phase voltage, so using the high speed switch and thereby also increasing phase voltage, will also yield a higher phase current and battery current. Am i on track here or?? Where did you came across the info about the speed switch being current based, because i have been thinking the same but unable to find any useful info anywhere.

Best regards

I know it's current based because I have a 300a shunt with a digital volt/ammeter. I can see the exact number in relation to each of the % settings for each speed.
 
2WheelsMovesTheSoul said:
I know it's current based because I have a 300a shunt with a digital volt/ammeter. I can see the exact number in relation to each of the % settings for each speed.

Okay, nice! That is the same behavior I am seeing then. What a dumb design, a current limiter that changes.. Unfortunately that kind of makes the controller useless to me now, as i wanted a controller where I can control the battery current and have a speed switch. Unlike my old standard BLDC square wave controller that is limited to 35A battery current, also with a speed switch. But that one will only use 35A no matter what speed is selected..

Oh well, I paid money and learned something :wink:
 
basement said:
HI All,
my vespa conversion is done, and very pleased with the result.
It rides better than before. I have a 60V battery and a KLS-7230n controller on a 3Kw 205 motor.
Top speed is about 58kmh, thought it be a bit more but in the end, that's fast enough.
I love the acceleration.
The problem that occurs now, is that when I approach the last third of the battery I can not accelerate anymore (or at least not full throttle) before the BMS shuts down the battery (in a protection mode.)
I draw too many amps I guess... so what setting do I lower on the Kelly Controller to avoid that? without loosing all my acceleration power when the battery is full.
or is there a way to reduce amps draw in relation to the battery voltage?
thanks for your reactions .
All the best,

It sounds to me like a battery (cell group) issue. If the voltage drops to low the controller should limit before the bms cuts.
How much voltage drop do you have?
However if one cell group drops too low, it will probably not trip the undervoltage in the controller.
But the bms will turn off.
 
Back
Top