My burnt FETS story or rant as it maybe

[jimmythekid1]

I have often heard don't need a fet upgrade for liths, but personally I think a FET upgrade is good insurance. I can't speak for evos since I've never had one, but gen 1 FETS can handle a consistent 2 amps before you run into problems. A normal rwd xmod with stock power supply rarely reaches 1 amp under normal driving conditions. But using some tools or toys I have I've tested to find that a stock xmod can peak over 2 amps for a short time with no problems, the tools I used were a low amps probe and an oscilloscope.

OK lets us an extreme case, ok you have just installed an awd kit, something is out of alignment, causing binding and the car barley moves, then you get stuck on a fly turd and the car won't move. Did I let the throttle go? No I hold it down and try to get unstuck, i do this for a long time, and what do you know my motor is **** hot. So I finally give up and go ahead and fix my awd issue and the **** car still won't move, after further inspection I realized I overheated and burnt my FETS.... So what happened?

All they binding overloaded the motor, the harder it had to try to move the more current it drew, causing it to burn FETS with stock power supply. That is a true story, it happened to me.

Now lets us ohms law

voltage divided by resistance equals amps
6volt/6.66ohms=.9 amps normal running motor RS S2

8.4volts/6.66ohms=1.26 amps running normal RS S2
with liths running normal we are just .74 amps away from possibly doing damage, now if something binds or we get stuck it is much easier to burn FETS.

That is why I always recommend a FET upgrade or V2 with a power supply upgrade.
It may not be 100% necessary but it is good insurance, and good time to modify your board is when you’re adding liths. Also when you get board of liths and a stock motor you will already be set up for a hot motor.

Thanks for taking the time to read this,
Jimmythekid1

[sicSCION]

i ran my car in stock form and added a 7.4 li-po pack in addition to my 4 aaa
result: blown

[noturday]

haha the liths are supposed to replace the 4 aaas not combine with it, and if i do liths im gonna upgrade and stack my fets b4 i even turn it on

[sicSCION]

i thought it was pretty funny .car ran sooooo fast i wish i had a speed checker on hand to see exactly what it was pulling

[noturday]

yeah i hooked up a 9v to a gen 1 car and it flew for about 30 sec till it blew the board

[mustanglover]

i had alot of blew fets from a 6TH CELL!

[xmodsnut]

man I think I trashed one of my 05 stangs running only 4 1.2 volt 850mah energizers it has every upgrade imagineable on it but left the batteries at four. I noticed that after three runs of 20 laps on my xmods track, I had to recharge in between runs, my s2 motor and terminals were hot. it runs good but wont steer at the same time as I drive it and stops every few seconds now and if I hit the wall.

[meme405]

...dont stack fets get a V2.2 board or a nelly upgrade trust me their 5 times better...i've had one of each...especially if you plan on doing it yourself...its a hard *** upgrade

[aaronz350z]

i installed lithium on my gen 1 and it blew the fets

[snowboi1289]

Now dude !! Come on, this is like a year old, please read the rules.

[Donziikid]

As snowboi has said, Aaron, please review the rules and refrain from bumping old topics.

Closed.