Split PPM Confusion

General Discussion
1

Hey Guys. After reading a bunch on the difference between canbus and Split PPM, I am left with one confusion

Which settings do you split when running dual motors via Split PPM?

I have a dual Kaly 6355 build using FOCBoxes and a 10s4p 30Q battery

BLDC Hybrid

Motor Max: 50a (Kaly Max 60a) Motor Min (regen): -30a Batt Max: 50a Batt Min (regen): -7a Absolute Max: 130a (default)

I set each vesc individually and did a motor detection for each. Which settings are split? I split my regen not sure if Motor Max, since each vesc is running independent?

Can someone clarify and confirm my settings?

Thanks

2

if im not mistaken you dont split any settings. you set each motor up individually to the foxbox as you would a single drive, and then once theyre both configured individually you connect a y split ppm cable

3 Likes
3

I would think at least regen since both motors are sending power back to one battery

4

yes, you split the (usually white) wire coming out of your resistor receiver. leave the black and red only connected to one ESC though.

5

you mean like what should divide in two? yeah, if you only want 40a regen then set each esc to 20.

6

I was worried about Battery Max

7

whatever the number you set for one ESC is, the two ESCs together will do double that. If you set batt max to 60 on each ESC, they can draw up to 120 together.

the ESCs aren’t “aware” of each other’s existence, treat them like two seperate systems

8

Ok that’s what I thought so 10s 30Q 15a discharge, I am fine with 50a for each, right?

How would you set it lower than the Motor Max?

9

what’s your parallel number? 10s doesn’t tell me much about max current

10

10s4p 30Q Battery

11

Motor Min and Battery Min should both be negative.

12

with 4p, your maximum discharge is 15 * 4 = 60a, 60/2 = 30, so i wouldn’t do over 30a per vesc

13

yes sorry I will correct the post

1 Like
14

Also does your battery have a Max discharge limit BMS of 60 or 80 amps. Don’t want to exceed that either

15

Wait a second… I’d say batt max and min should be no more than half of what you would have set for a single motor system, unless you’re running the vescs off of two separate batteries…

16

Even if the Vesc are running independent?

17

Someone correct me if I’m wrong, but yes, even when vescs are running independently.

Batt max is roughly how much each vesc is allowed to pull from the battery, right, and that shouldn’t exceed half of what the battery can safely deliver if you have two vescs pulling amps from your batts.

Batt min is how much you allow vesc to pump back into the batt, and cell specs stay the same even if you’d have 10000000 independent vescs :blush:, so you don’t want to charge cells with heavier current just because you happen to run dual motors.

18

See, confusing. If I set my battery max to 25a wouldn’t it be the same as setting my Motor to 25a?

19

Short answer is no. If battery max and motor max were the same thing, we wouldn’t have two separate settings :smirk: A bit confusing yes.

3 Likes
20

So if I set my Battery Max to 25a i shouldn’t see any performance difference?