ioxqq

I have a few packs of Orion 3200 want to see which has the best avg volt. Want to know what is the discharge cutoff voltage should I set?

kn7671

iTrader: (16)

If you really want to discharge for Avg Voltage, set it to about 7.4 volts. This should be low enough to simulate a 19T/10.5 5-minute race.

Just as a reminder, LiPo manufacturers do not recommend discharging. So if you do, don't go any lower than what you would have normally incurred during a race. For a stock race, I normally find the voltage around 7.6V - 7.8V with about a 1600-1900mah charge required to reach 8.4V. As I recently learned, as the traction gets greater during the raceday, you will use more energy during a 5-minute race.

magm20001

iTrader: (5)

7.4v? lol the nominal voltage is only 7.4v

set it to 6volts

considering the novak esc has cutoff at 6v you'll be fine

wallyedmonds

they will be so close it dosent matter.
its lipo not sub c cells.

kn7671

iTrader: (16)

Right, but what you're really wanting to find out is the avg. voltage in the charge range that you will be using it, not the fill avg. voltage of the pack. When was the last time you ran a 5-minute race and the battery was only 6V after the race?

magm20001

iTrader: (5)

dude, if he set cutoff at 7.4v the orion lipo even at 10amp discharge would cutoff within 30 seconds.

hobbipro

iTrader: (23)

Isnt the discharge of each individual lipo cell 3.2v, or 3.4? So since the orion is a 2s lipo, actual cutoff should be 6.4v, at least thats what I thought I read on the orion sheet that came with my batt.

kn7671

iTrader: (16)

What I'm trying to say is that it doesn't make any sense to gather data for the Avg. Voltage for the full 3200mah charge since you normally only use 1600-1800mah during a 5-min race.

After a 5-minute Stock 13.5 race, I observed the race ending voltage on my 3200's to be around 7.6 Volts. During a 5-min practice race on a 10.5, I used about 2100mah and the ending voltage was 7.35 Volts.

With the data from multiple runs, ending voltage, and recorded mah charge placed back into the battery, I know exactly how many mah's I have used based on the voltage of the pack.

Now back to the real question, if you only used 2000mah's during a 5-min race, and 2000mah's of discharge equals 7.38 Volts, why would you want to test the Avg voltage down to 6.0 Volts? Data down to 6.0V is useless since you are only using the top 50% or so of the battery's real full charge capacity. Also, the 6.0V rating is just the Avg Voltage that LiPo makers provided as the fail-safe stopping voltage. If you run your LiPo down below 7.0 Volts and can't tell, something's wrong with you.

Just for everyone's info, if you use 3200mah out of your Orion LiPo 3200 pack, the ending voltage will be about 6.76 Volts, not 6.0 Volts. The mah rating down to 6.0 Volts would be well into 4500mah, but with the voltage so low, they are not usable for racing.

kn7671

iTrader: (16)

Here is some other good info for you guys:

Ending voltage - 5-minute race - 1625mah used on a 13.5 BL Novak Sintered Motor

3200 LiPo - Ending Voltage = 7.570 Volts = 24981 rpms
3600 LiPo - Ending Voltage = 7.660 Volts = 25279 rpms
4800 LiPo - Ending Voltage = 7.844 Volts = 25886 rpms
5000 LiPo - Ending Voltage = 7.866 Volts = 25958 rpms
7000 LiPo - Ending Voltage = 8.018 Volts = 26460 rpms

I think's it obvious why capacity is most important specification for a battery, as higher average voltage over a 5-minute race means more power, and more speed/rpm capability. I don't know who makes a 7000mah battery that fits a TC, but if there was one, it would be nice. The jump from a 3200 LiPo to a 5000 LiPo is obviously better.

magm20001

iTrader: (5)

7.4v without anyload, you dont test voltage when there isnt any load. you check when there is a load applied to it