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BrianG · 06.02.2007, 07:11 PM

When a pack reaches 3v/cell (or whatever value you set) under load, the ESC cuts off. Once you disconnect the pack, the voltage will come back up. Some of that is because the pack is no longer under load, some is just the cells drifting back up. So, after 20 minutes or so, the pack will actually have a higher voltage.

That said, the LVC setting really depends on the load. For high pulse loads (like in cars), you can get away with a slightly lower LVC setting because the average current is much less. Plus, you wouldn't want the LVC to kick in falsely as it dips for the few ms the load pulse lasts. For a constant load, you'd set a higher cutoff because of the constant high drain. You also have to take battery quality into consideration because the good cells will drop less under load.

So, instead of trying to consider all this, I just start with a 3v/cell cutoff. If the pack voltage (after a 20 min rest) is over 3.7v/cell, I drop it a little to 2.9v. Or, if the pack voltage is under 3.5v/cell, I increase the LVC until the pack is right around 3.5-3.6v/cell after rest.

	(#12)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	06.02.2007, 07:11 PM When a pack reaches 3v/cell (or whatever value you set) under load, the ESC cuts off. Once you disconnect the pack, the voltage will come back up. Some of that is because the pack is no longer under load, some is just the cells drifting back up. So, after 20 minutes or so, the pack will actually have a higher voltage. That said, the LVC setting really depends on the load. For high pulse loads (like in cars), you can get away with a slightly lower LVC setting because the average current is much less. Plus, you wouldn't want the LVC to kick in falsely as it dips for the few ms the load pulse lasts. For a constant load, you'd set a higher cutoff because of the constant high drain. You also have to take battery quality into consideration because the good cells will drop less under load. So, instead of trying to consider all this, I just start with a 3v/cell cutoff. If the pack voltage (after a 20 min rest) is over 3.7v/cell, I drop it a little to 2.9v. Or, if the pack voltage is under 3.5v/cell, I increase the LVC until the pack is right around 3.5-3.6v/cell after rest.