MGM Low Voltage Cut Off - Owners READ

[BrianG]

Originally Posted by bdebde

...20c batteries are the problem, 25c seems to work ok for me (still not for others)...

That would lead me to believe that the LVC on this is too sensitive and is responding to the very brief dips in voltage during high current bursts. MGM ought to add a little delay to the LVC circuit/algorithm.

Does the MGM have an option to increase punch control? That would pull less current from the battery, which would keep the voltage from dipping to the LVC threshold as easily.

No option for the punc control, but we can adjust the time to reach 100% of the full trottle. But somes guys here had try to adjust it but not solve the problem.

[bdebde]

Originally Posted by BrianG

That would lead me to believe that the LVC on this is too sensitive and is responding to the very brief dips in voltage during high current bursts. MGM ought to add a little delay to the LVC circuit/algorithm.

Does the MGM have an option to increase punch control? That would pull less current from the battery, which would keep the voltage from dipping to the LVC threshold as easily.

It has accel setting from .13 to 3.0 sec (basically same as punch control on MM). Higher settings help, but then you have no wheely action and lame acceleration.

Originally Posted by bdebde

It has accel setting from .13 to 3.0 sec (basically same as punch control on MM). Higher settings help, but then you have no wheely action and lame acceleration.

Even with my setting set to 2.9 I still have a problem. I think that for some batteries may be the whole issue. You need good lipos to run the types of setups we are running, I accept that. But for most I think the problem has to do with either the LVC being way too sensitive or a factory setting is off. If my batteries were breaking a sweat that would be one thing, but they are not even getting warm. My problem is so bad it does it even when the truck isn't on the ground. Under a light load such as this there is not much strain put on the batteries.

The idea of running an external lipo cutoff or a warning system is a good one, and I am looking into that, but I still think it is ridiculous that we should have to resort to that to get the performance we paid for. Plus we lose the overload protection that truly is a good feature to have.

Those who have had problems try this and let us know what happens. Set the truck to race mode with a full pack and run it for a few minutes. Does your performance increase? Log the data on the computer and compare your Max Amps and your Max RPM.

For me just holding the truck off of the ground and making this comparision I can tell a huge difference. The reduce RPM mode and especially the cutoff mode interfere and cause my performance to be mediocre. As I said on the cutoff setting it won't even go past partial throttle.

[jhautz]

You dont have to loose the over current protection if you just set it to NiMH mode rather than race mode. That disables the internal LVC but not the over current protection. Then you could run the external LVC.

I had sucess with running mine with a slower spool timing, but I do agree it takes some of the fun out of the powerfull setup when you need to dail it down just to keep the oversensative LVC in check.

The external LVC that was linked to below works great by the way. Its no frills and no nonsense. It just works. I use it on a BK 12020 controller and its works perfectly. When the voltage dips below 3.0v/cell it just cuts off. When it comes back above 3.0v it turns back on. So when you hit your limit the truck just kinda starts to stutter a full throttle and you know your pack is about ready to dump but it still lets you drive it back in.

I actually like that solution. Could be a winner.

EDIT: One thing I just remebered... dont plug a half dead pack into that external LVC. It does seem to have a hard time sensing the number of cells in your pack if its not close to full when you plug it in. It might sense a 4s pack instead of your partially charged 5s pack. Could cause a problem if your not carefull.

Originally Posted by jhautz

You dont have to loose the over current protection if you just set it to NiMH mode rather than race mode. That disables the internal LVC but not the over current protection. Then you could run the external LVC.

I had sucess with running mine with a slower spool timing, but I do agree it takes some of the fun out of the powerfull setup when you need to dail it down just to keep the oversensative LVC in check.

The external LVC that was linked to below works great by the way. Its no frills and no nonsense. It just works. I use it on a BK 12020 controller and its works perfectly. When the voltage dips below 3.0v/cell it just cuts off. When it comes back above 3.0v it turns back on. So when you hit your limit the truck just kinda starts to stutter a full throttle and you know your pack is about ready to dump but it still lets you drive it back in.

I actually like that solution. Could be a winner.

EDIT: One thing I just remebered... dont plug a half dead pack into that external LVC. It does seem to have a hard time sensing the number of cells in your pack if its not close to full when you plug it in. It might sense a 4s pack instead of your partially charged 5s pack. Could cause a problem if your not carefull.

NiMH mode doesn't have a cutoff? If so this could be the best solution for now.

[hobbimaster]

I have never tried mt LVC on my 16018 either. I bounce back and forth between 2 4600 7-cell packs and 2 orion 4800 packs, so I just use NiMh mode. In all honesty its easy to know when to stop running a set of lipo's. Performance drops quickly and it will start to slow down. As long as you take notice in performance/speed loss, you'll know its time to pull her in. We use to do this all the time running Novak and LRP speedo's in 1/10th, pre-LVC days.

I ordered the Li-Saver, hopefully this fixes the problem. Still I would like to see a software fix for the LVC.

Anyone else using this method?