MMM auto lipo cutoff or 6.0 volts?

[VintageMA]

Originally Posted by Sower

I don't get it . . . changing the voltage drastically changes all the characteristics of the system. I think most people set up a system with an end use in mind and stick with it. Why are you changing the voltage for your systems?

Generally I agree, but I can think of two scenarios:

1) HV - the more cells you use, the less of a difference a change makes. If you are using 2 cells, then yes going to 3 is 50% more speed. But if you are using 5 then going to 6 is only a 20% change. I have a setup that is going to be a nice powerful ride on 6S geared for ~42-44, but will want to drop down to 5S for some calmer driving around.

2) Doesn't apply to me, but if you have an ESC you want to switch between rc's with different setup it would make things a little easier than having to reprogram every time.

[Sower]

I see. I guess I've always been trying to nail my setup for a very specific use and only that use so I've never looked at it that way. Interesting.

When I started building my current system I knew I wanted 6s HV, low amps and it's working awesome. This weekend I was getting 25 minutes of runtime at the track going full out in my XT8. Motor temp never broke 100.

[rabosi]

Originally Posted by Sower

I don't get it . . . changing the voltage drastically changes all the characteristics of the system. I think most people set up a system with an end use in mind and stick with it. Why are you changing the voltage for your systems?

I use 4s for conservative (and for ferrying vehicle), 5s for "oh yeah" and 6s for "holy *%$@". Because of this I have it set to auto lipo (or would have to carry a laptop) but I never run the battery down. I stop as soon as I detect slowing down.

ps, imo why pigeon hole your monster anyway. Beat it anyway you can damn it!!

[Sammus]

I think there is a problem for auto detect of many cells. Think about it, if you have a 5s fully charged (~21V) or a 6s slightly discharged (~21V). How would it know the difference?

[Arct1k]

It doesn't - There has always been this issue - you have to be careful with empty packs...

That is why they have the tones for the cell count

[Sammus]

Yeah I know, I read someone say that autodetect only works for 2s and 3s and someone wrote they should put it in for all cell counts, and a bunch of people all agreed, I was just explaining why it might not be suitable for higher cell counts...

I have never trusted the auto lipo setting, always using my own voltage amount for the LVC

[rabosi]

To state the obvious, if you're running auto detect then you should always run fully charged packs. As an example fully charged 6s is around 25v and fully charged 5s is around 21v. That's a significant difference and circuit should have no issue auto detecting imo.

[rabosi]

Someone on the traxxas forums noticed that the mmm beeps for the number of lipo cells detected. I tested with 5s and 6s and it did beep 5 & 6 times respectively. A good way to verify that packs are detected correctly. It does say this in the manual too btw.