Originally Posted by wfdfiremedic
quick question. I have an orion 4800 lipo that I want to use with a esc that does not have a lvc built in. From reading orion's site they state that you can run it without a lvc as long as you stop driving when it dumps. I have only used lipos with esc's that have lvc's built in. When the lipo dumps will this be obvious? Am I playing with fire by not using an lvc? The only reason I ask is that when I have hit lvc before it is not obvious that the pack has dumped....it feels just a tad slower than the first lap.
You probably don't need a LVC with the Orion/Kokam packs. This ONLY applies to Kokam cells.
I run a bunch of lipo cycling fixtures at work. A couple months ago, the power went out in my lab over the weekend. The cycling machines went dead and those fixtures put a small parsitic drain on all the batteries on test.
When I arrived at work monday - all the cells were discharged to about 1V/cell. Oh F@#$. I decided to turn the fixtures back on to run a couple of cycles anyways. The Kokam cells were at 100% capacity with no increase in IR. All the other manufacturers cells from 3 other manufacturers lost 20-50% of their original capacity. I let the Kokam cells run another 100 cycles...good as new. The cells from the other manufacturers were destroyed.
Kokam says that 2.5V/cell under load is the absolute minimum the cell should be discharged to. Usually, they say to stay above 2.7V/cell to have a little bit of a buffer.
I've been running an experiment testing the limits of the cells and purposely set the low voltage at 2.2V/cell, which is far below the Kokam recommended limit. I'm at 400 complete cycles already and there is virtually no degredation in cell performance.
You will definitely feel the car get much slower when the cells are at 2.7V (5.4V as a 2 cell series pack).
I don't use a LVC and pull my car off when it slows.
The only danger of running the cells that low is that there is a much greater chance of your cells drifting out of balance - thus making a balancer necessary.