godofcable

My Feedback: (4)

So I put a Velineon brushless in my Slash.

Had a few problems from the start. It seems like the low voltage cutoff is acting up. I put a fully charged 7 cell NIMH 4200mah in, and within 30 seconds the LED is flashing red.

If i follow the instructions and shutoff the low voltage cutoff, it runs fine.

Is it that I'm using a NIMH? Maybe its setup wrong? I just plugged it in and went, didn't really monkey with it. Only thing I did do was change the throttle setting to 70/30 and readjust the ESC for that.

4goodbuys2

Sounds like the lipo cutoff was turned on to me.

redfisher1974

Yes turn it off for NIMH.

cooldriver385

Most likely the low voltage cutoff was turned on. It might have read a fully charged/slightly discharged 8.4V battery as a 3S 11.1V lipo that's getting low. If you turned it off and it works fine, then you should be fine.

hpiracr28

having low voltage cutoff on or off with a charged nimh shouldn't give a problem. ive had it on or off sometimes and i get the same run times. could be an unbalanced cell tho. book says always turn off when using nimh.

godofcable

My Feedback: (4)

its just odd. When its off, it goes like a monkey with a hangnail.. With it on, I get thirty seconds of runtime and it shuts down.

SyCo_VeNoM

not odd actually
7 cell's fully charged are around 9V fully charged without a load. the ESC's cutoff is detecting that as a 3s at 3v a cell which is the absolute lowest you want to discharge a lipo to.
Only reason people don't notice that issue with a 6 cell battery when the lipo cutof is on is cause a 2S lipos only 7.4v which is close to a 6 cell nimh

4goodbuys2

I have the same problem when I have the LVC on while running nimh

godofcable

My Feedback: (4)

help me understand LIPOs. So even though they are a lower voltage, they offer a higher output? How does that work? I tried searching on the forum "understanding LIPOs" Didn't offer much. I'm sure if i read every thread out there i would eventaully find the info, but its so much easier just asking

SyCo_VeNoM

3s is lower than 2 6 cells in series
each lipo cell is 3.7V so 2S is 3.7V X 2 = 7.4V (fully charged they are 4.2V's each though)
NiMh is 1.2V a cell so a 6 cell stick pack is1.2V X 6 = 7.2V (a fully charged NiMh is around 1.5V's a cell)

NiMh's voltage drops over time, and at the start it has a sharper dip though(specially if you gun it).
Lipos on the other hand retain a higher voltage longer, and do not dip under load.

Example Lets say I take my 6 cell NiMh out and run it for 20 minutes. After the run the voltage will probably read somewhere around 2-3 volts on a multimeter.

Now I'll take a fully charge lipo out (a 2s is actually 8.4V's fully charged ) and run it the same time. The battery chances are will read somewhere around 7.6V's or so still. So essentially I'll still be running at the same speed the fully charged NiMh does at the start of the run.

Pretty much in the end it equates to longer run times with a more constant voltage being applied.

2 stick packs IMO will be faster than a 3S lipo at the start but after 10 minutes the 3S lipo you will not notice a degradation in speed like you will after a few speed passes of the nimhs

godofcable

My Feedback: (4)

Blue loctite on the jam nut on the spur gear? mine keep loosening, wondering if i should use blue loctite. thanks.