smart stop lipo cut off when using NiMH?

[Needler56]

am i supposed to be using the smart stop lipo cut off for the gtb when i switch to NiMH packs? is there a way to shut it off or do i have to disconnect it every time i use a non lipo? it blips the throttle almost right away and shuts it down after about a minute

[GSMnow]

YES, in most cases, you need to shut off or remove a LiPo low volt cut to get any real run out of a NiMh pack. I ran into the same problem trying to run my Mamba Max on NiMh after I set the Low Volt cutoff. It certainly will not hurt anything, it just won't go. Even on a full charge, the NiMh pack will dip under 6 volts under hard acceleration which causes the cutoff to activate. With my Mamba Max, I have to either use a PC or do the "stick programming" to change the setting, and it is a pain. An external cutoff unit would be so much easier to just plug around. I am looking at getting an external one for my older ESC's, and I will try in on the Mamba as well just for this reason.

[Needler56]

thanks for the sanity check! so some esc's with built in lipo cut off isn't a seperate profile? it's just set with every profile?

[GSMnow]

I know my Mamba Max pretty well, it is just one of the many settings you can adjust, "cutoff voltage" it can be set from disabled to 12 volts. The Mamba Max does not use "profiles" so you just change what parameters you want to. It would be nice if I could make up a few "profiles" and easilly select between them,. but it does not do that. I don't know how Novak did it in their's.

[rccardude04]

Couldn't you put a receiver switch inline with the cutoff so you can turn it on when you run lipos and off when you run NiMHs?
-Eric

[GSMnow]

With an external cutoff device, you could make a bypass switch setup. The ones I am aware of interrupt the RX pulses to the ESC to put you in neutral when the voltage goes too low. They just use a male and female 3 pin RX plug and go between the RX and ESC. Then they also monitor the pack voltage with another wire or so. If you are not running LiPo's, just plug the ESC straight to the RX and don't go through the cut off unit. A switch could be added to do the same thing, but it is not really needed. In my Mamba Max case, the low volt cut is just part of the program in the ESC. There is no hardware way to stop it from functioning. I have to program it out if I want to run NiXx batteries.

[Needler56]

so what if i have an emaxx and use one lipo and one nimh, are esc's these days smart enough to distinguish between the two?

[ElectricThunder]

Some ESCs can distinguish battery types (such as the LRPs and I think Novaks can do this). That doesn't mean you can hook up two different kinds of batteries though. It'd probably confuse the ESC, and either way you slice it, the one cutoff it does pick (or lack of a cutoff) would be either unsafe for the lipo, or performance hindering for the NiMH and the overall setup.

It's a bad idea to hook two different battery chemistries up to the same ESC. But that's another story.