RC-Monster Forums - View Single Post

zeropointbug · 04.09.2007, 04:37 PM

Really, I thought not everyone was having issues?

I wonder how 7s A123 pack would do? Same 25.2 volts at fully charged. However, you CAN use a 3.45 volts to charge, I think you get about 95% charge, and takes a little longer (3.45 float charge voltage), so that's 24.15 right off charger. But as soon as you discharge a little bit out of an A123, the voltage goes down to operating nom. volts instantly. I bet a 7s A123 might work fine.

It's basically a problem of discharge curve, and voltage droop of batts. If batteries had a very good discharge curve (like A123, or better) and very little droop, you would need less cells to get the working voltage. It's better for everything really...

Altair Nano cells are going to be 2.4 volts/cell, which is nice, gives you more voltage options. They also would last a lifetime, LITERALLY, they have put 10's thousands of discharge cycles on them at 10C discharge/10C charge, they retain over 85% capacity still at that point (16,000 was the latest figure)

	(#19)
zeropointbug Z-Pinch racer Offline Posts: 3,141 Join Date: Nov 2006 Location: SK, Canada	04.09.2007, 04:37 PM Really, I thought not everyone was having issues? I wonder how 7s A123 pack would do? Same 25.2 volts at fully charged. However, you CAN use a 3.45 volts to charge, I think you get about 95% charge, and takes a little longer (3.45 float charge voltage), so that's 24.15 right off charger. But as soon as you discharge a little bit out of an A123, the voltage goes down to operating nom. volts instantly. I bet a 7s A123 might work fine. It's basically a problem of discharge curve, and voltage droop of batts. If batteries had a very good discharge curve (like A123, or better) and very little droop, you would need less cells to get the working voltage. It's better for everything really... Altair Nano cells are going to be 2.4 volts/cell, which is nice, gives you more voltage options. They also would last a lifetime, LITERALLY, they have put 10's thousands of discharge cycles on them at 10C discharge/10C charge, they retain over 85% capacity still at that point (16,000 was the latest figure) “The modern astrophysical concept that ascribes the sun’s energy to thermonuclear reactions deep in the solar interior is contradicted by nearly every observable aspect of the sun.” —Ralph E. Juergens