9xl w/ 6S LiPo and BK2099
 

Hello,
I am running an e-maxx with the following specs:

Motor 9xl
esc BK 2099
Batts 6 Series LiPo (22.2 volts) 4.4 Ah Rated for 10C discharge
Spur 66T
Pinion 17T
Weight 10lbs 4oz.

So far I have had 2 esc go up in smoke! The batts don't even get warm and run times are around 30 min. I don't think that I am over current.... I have a fan on it.... Any thoughts?

I am thinking of upgrading to a 36120.

Thanks
Michael

Welcome to the forum Wngdawg. seems like a few have looked but no one has an answer for you yet. Hang tight, the guru's will be around to toss this one around for you.

your gearing might be to low causing the batteries and motor to run cool but the esc to be extremely hot.

I have a TXT-1 with the 9XL,9920 and 6 cell lipo as well,but I use a 54t spur with 14t pinion.My truck is 12 lb 9 oz,a fan on the esc and heat sink on the motor.The esc rarely hits 100 degrees the motor hits 100 from time to time and 120 under hard consistant top speed runs.But I've never smoked an esc.

The gearing being low would make motor run hot and esc cooler. You seem to have th truck geared about right. 6s lipos is about 18.5 nimh cells to voltage. Was the other two ESCs bk 9920. The 36120 is a nice controller but has a 42000 rpm limit. You should be under that. Do you have any drag in the rc? Make the esc draw more than should.