L4 / L6 with Navitas AC / 600A?

[fstop]

Originally Posted by luvdamud

Fstop, the cart is between 1000 and 1100lbs with the lithium battery. I have stock 20" tires and 16:1 rear and yes, I have slowed to very low mph and floored it many times. I love how it throws gravel when floored.

As far as your hesitation, I did experience that some due to voltage sag when my lithium pack would start to get low. I have a custom battery config using one of the lithium profiles (as told to do by Navitas) but when my pack would get low, a high amp acceleration run would make the voltage sag and the Navitas would throw a low voltage error and then immediately go away. I had to do a screen capture to actually catch it happening. I lowered the voltage in my config and that problem went away. It took a little trial and error to catch and to be honest, if I wasn't running the Lithium config in the Tac2 it probably would not have happened.

Great info - thanks for posting.

Question - What FW profile (RXV or L6 or generic etc...) and version are you running on your Tac2?
What are your "off road" settings (accel ramp rate and max accel)?

Issues I mention aren't related to voltage sag - ruled that out long ago.

Your 20" tires and 16:1 gears are I think possibly why you don't notice this issue.

I've got stock 12.5:1 gears and 22.5 (actual, say 23 on sidewall) tires so I've got a harder load for the motor to move.

Cart weights are in the same ballpark.

I can eliminate the harsh jerking just by lowering accel ramp rate parameter, but it also aggravates the hesitation that sometimes comes with re-acceleration. It's interesting that the stock setting for Accel Ramp Rate (usually 200) is so far out and causes these issues, but only in a 72v configuration. I had no such issues at 48/52v, with stock parameter at 200.
I need to use ~100 or so max to avoid the jerking upon hard re-acceleration from those slow speeds.

Thanks again for the info.

[luvdamud]

Not sure what FW profile means but I am set up the same as an L6. But I did take a look and I'm actually 17:1 on the rear end gear config, 200 on ramp rate and 4096 max acceleration. I can check the version once I get back out into the shop and connect to the controller. Here are screenshots of my config.

[fstop]

Originally Posted by luvdamud

Not sure what FW profile means but I am set up the same as an L6. But I did take a look and I'm actually 17:1 on the rear end gear config, 200 on ramp rate and 4096 max acceleration. I can check the version once I get back out into the shop and connect to the controller. Here are screenshots of my config.

Thanks - the version is on the FW tab, and would have a description followed by a number like 6.01 etc...

I think the high gear ratio may mask or eliminate what I'm noticing - a guess anyway. 17:1 along with smaller tires makes things much easier on your cart than mine, in any kind of acceleration situation.