MGM article on voltage under braking & lipo quality

[BrianG]

Does the ET truly not log negative current, or does it just not show it because the graph starts at "0"? Could someone set the min value of the graph at some value and see? I could do it, but I'm at work :shhhh:

[zeropointbug]

Interesting there, I have never seen a positive voltage rise after braking, but then again I do not brake that often, and I do not pound on the brakes, I'm quite easy on them.

Don't forget adding caps to the ESC, I am not sure how many you would need to reduce these voltage increases to a decent level, but probably you can't have enough... you would need something of capacity with very low esr.

I will do some tests sometime soon with my Revo under hard braking and the eagletree, see what we get for comparison.

[othello]

I found a better graph i posted some time ago (while i was running 10s1p A123) where i pointed out braking Amps and the corresponding rise in voltage. The green curve depicts motor rpm.



@BrianG
When opening the eagletree logfile with excel you won't notice any negative value. There is no way you can differentiate between amps flowing to the motor and amps flowing to the battery when using an eagletree logger (other then looking at the voltage).

@zeropointbug
The Kontronik Jazz 55-10-32 ESC is rated up to 43V (10s lipo). With 8s A123 (25V average) i'm well below it's rated max voltage leaving enough headroom for braking voltage spikes. Even with 11s A123 (36v average) i do not have issues while braking with the ESC. I too tend to run my ESCs below their rated max specs to avoid premature failing.

[zeropointbug]

Yah, I have ran 7s1p and 2p packs for 2 years now through my Quark with no issues... and when I got my G3 lipo packs, it started to cog alot, and do weird shutdown hiccups. This is an ESC that should never have even been designed for 6s lipo, according to alot of ppl on this board, including myself.

After I did the modifications to the esc, it has never ran so good, and I mean awesome. We will see how it holds up in the years to come....