EVX2 problem - maybe ?

[marcus]

With all the brushless antics going on with my trucks I figured it'd be a relaxing break to run my stock Emaxx in the snow with the dogs - they love it.

Anyhoo, I threw my 2S 5000 LiPos on and had some weird happenings.

The EVX2 wouldn't take a punch to WOT. It would just shudder slightly and cut out. I didn't have to reset the esc though, just throttle off and reapply more smoothly.
Same in fwd or rev.
Weird.
So I play around, test the connections etc, recalibrate the esc-tx but the same.
So I throw on a pair of 3000 nimh's and the EVX2 loves them. No problems at all !!
WTH?
I wasn't aware of an overcurrent lockout on the EVX2 but is the added punch of the LiPo's triggering something [?]