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Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 12:37 pm
by johnsongt350
Good day all!
I am having an issue with my conversion. I have a Tesla LDU and 16 Tesla model S battery modules. When placing the car in drive and applying pressure to the accelerator I have noticed it has a significant dead space. As the pedal is depressed the vehicle does not move until the pedal is about 50% depressed. What I have done is updated the parameters and calibrated the pedal with no luck. I am using a Tesla pedal.
Second major concern is the car has very little power. It will only accelerate up to about 30 mph. (48 kmh). It doesn't get there fast by any means. The car has very little power.
Please see attached parameters and let me know if you see anything.
Re: Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 1:13 pm
by johu
Your pack voltage is displayed as 333V and udcmin=320V . That is much too high. Set it to 250 or even 200V for now to take it out of the equation.
Re: Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 5:54 pm
by Zieg
Potmax is 4095, is that really what you're reading with the pedal to the floor?
Re: Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 7:33 pm
by johnsongt350
Zieg I just tested the pedal again and that is what I'm seeing. Maybe I'm doing something wrong however I was following the instructions for pedal calibration
Re: Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 8:41 pm
by johu
That is (unfortunately) quite common with many throttle pedals. They range from 0.8 to 4.2V while the analog input ranges from 0-3.3V. Some newer designs have a 1:2 divider to be able to use the full pedal range.
Have you tried changing udcmin?
Re: Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 8:50 pm
by johnsongt350
Yes just changed udcmin to 200. The car now has much more power.
Any recommendations on giving the pedal a different set of parameters
Re: Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 8:59 pm
by johu
Great
johnsongt350 wrote: ↑Tue Mar 26, 2024 8:50 pm
Any recommendations on giving the pedal a different set of parameters
No improvement possible on that front.
If possible you can add at 4k7-10k series resistor between pedal and throttle input and redo calibration. Then you can use the full range.
Re: Extremely low power and poor pedal performance
Posted: Tue Mar 26, 2024 10:58 pm
by Zieg
Oh, wow. So in effect the pedal will register WOT at that point and the rest of the travel is wasted?
Well for what it's worth, the Prius pedal on my Leaf OI board has a range of about 1000~3200 on channel 1 and 500~2800 on channel 2.
Re: Extremely low power and poor pedal performance
Posted: Wed Mar 27, 2024 1:03 am
by johnsongt350
Thank you.. I'll try a resistor or consider changing the pedal.
Re: Extremely low power and poor pedal performance
Posted: Wed Mar 27, 2024 8:07 am
by johu
Zieg wrote: ↑Tue Mar 26, 2024 10:58 pm
Oh, wow. So in effect the pedal will register WOT at that point and the rest of the travel is wasted?
Yes
Zieg wrote: ↑Tue Mar 26, 2024 10:58 pm
Well for what it's worth, the Prius pedal on my Leaf OI board has a range of about 1000~3200 on channel 1 and 500~2800 on channel 2.
The Leaf boards based on Mini Mainboard already have the 1:2 divider on board. The older ones don't. Which one have you got?