2fast4u
12-01-2007, 07:20 PM
I just started using EP4600's and I really want them to last long and stay stong.
So I started doing the bare minimum for weekly cell excercise.
My normal routine is to tray my cells to .90V before charging.
I was thinking do I really need to go that low? Think of Lead-Acid batteries and Li-Po's: These batteries are sensitive to DOD (Depth of Discharge) and going deeper into the cell's discharge shortens the life of the cell. I race mostly just stock and I love the bigger batteries since I can hold faster laps with a more flat discharge curve than one that looks like a cliff. If I tray my batteries on my NOVAK smart tray to .90V it normally takes about 45min to get a raced used pack from last week to EQ. Then I spend another 50 MIN charging what I just zapped out of that pack for the race.
This is what I was thinking for prolonging the life of my batteries. Just equalize to the highest level possible. In my case my Novak Smart Tray SE will do 1.2V to 0V in increments of .1V. I measure an individual cell volatage and pick the level just below that.
Besides the DOD effect, There is the over-charge effect. Some cells do not charge at the same rate as others. If you have a cell that is charging at 5% slower than the rest that could be as much as 250mah lower capacity at the end of a PEAK DETECTION CHARGE set at ZeroMV. But most people account for this so the end up changing the peak to like 3mv, 4, 5, ect per cell so that all the other cells have to endure an overcharge to get the weaker cell charged. This effect gets worse when you have the PEAK DETECTION overrun time set too. Some overruns are set for 3, 4, 5 minutes after the peak has been detected. OUCH to used to be good cells.
I aviod the overcharge effects just by having Peak at ZeroMV and no overrun. I perfer to use trickle of 250ma for about 10min to stablize the cells into their real peak values. On top of that, with the cells being EQ closer to their real peak values, even if one cell charged at 5% less, the differences in individual cell values would be less since less charging needed. Think about it, 5% of 5000mah charge from .90V is 250mah, 5% of 2000mah charge from 1.20V is 100mah. This means when the peak is detected, a pack that was EQ at a higher level will have cells peaking closer together in time than a pack that is being charged from a lower EQ such at .90V or even worse 0.00V!!! When the cells start peaking closer to together in time, it makes the charger detect the real peak value sooner and more accurate saving the life of the battery pack.
Just my thoughts, whats yours.
So I started doing the bare minimum for weekly cell excercise.
My normal routine is to tray my cells to .90V before charging.
I was thinking do I really need to go that low? Think of Lead-Acid batteries and Li-Po's: These batteries are sensitive to DOD (Depth of Discharge) and going deeper into the cell's discharge shortens the life of the cell. I race mostly just stock and I love the bigger batteries since I can hold faster laps with a more flat discharge curve than one that looks like a cliff. If I tray my batteries on my NOVAK smart tray to .90V it normally takes about 45min to get a raced used pack from last week to EQ. Then I spend another 50 MIN charging what I just zapped out of that pack for the race.
This is what I was thinking for prolonging the life of my batteries. Just equalize to the highest level possible. In my case my Novak Smart Tray SE will do 1.2V to 0V in increments of .1V. I measure an individual cell volatage and pick the level just below that.
Besides the DOD effect, There is the over-charge effect. Some cells do not charge at the same rate as others. If you have a cell that is charging at 5% slower than the rest that could be as much as 250mah lower capacity at the end of a PEAK DETECTION CHARGE set at ZeroMV. But most people account for this so the end up changing the peak to like 3mv, 4, 5, ect per cell so that all the other cells have to endure an overcharge to get the weaker cell charged. This effect gets worse when you have the PEAK DETECTION overrun time set too. Some overruns are set for 3, 4, 5 minutes after the peak has been detected. OUCH to used to be good cells.
I aviod the overcharge effects just by having Peak at ZeroMV and no overrun. I perfer to use trickle of 250ma for about 10min to stablize the cells into their real peak values. On top of that, with the cells being EQ closer to their real peak values, even if one cell charged at 5% less, the differences in individual cell values would be less since less charging needed. Think about it, 5% of 5000mah charge from .90V is 250mah, 5% of 2000mah charge from 1.20V is 100mah. This means when the peak is detected, a pack that was EQ at a higher level will have cells peaking closer together in time than a pack that is being charged from a lower EQ such at .90V or even worse 0.00V!!! When the cells start peaking closer to together in time, it makes the charger detect the real peak value sooner and more accurate saving the life of the battery pack.
Just my thoughts, whats yours.