This page is where I stored the history of my battery charging. The reason I put it here instead of a spreadsheet or notebook is that I need to be able to update this from any computer.

For information on how to charge these batteries, visit http://blogs.garypuppa.com/trex500/lipo-battery-charging

I store the history to characterize the batteries.  I have three Flightmax 2650 Lithium Polymer batteries, labeled A, B and C.

  • Flightmax 2650 (www.zippybattery.com)
  • 22.2 volts
  • 2650 mAh
  • 6 cells (6S))
  • 20C
  • My 6 cell battery will output (6 cells x 3.7v = 22.2 volts) during normal flying operation.
  • A LiPo cell is discharged when its voltage falls to 3.0 volts/cell.
  • My 6 cell battery is fully discharged at (6 cells x 3.0 volts) = 18 volts.  Time to land the heli.

The tables below assume a fully charged LiPo battery. After flying, I update the table with how long I was able to fly and how much juice I had to push back into the battery

Battery A

# Charge Date Flight Time Flight Style Post Flight Volts Charge Time minutes
mA Pushed In Post Charge Cell Voltage Comment
1 2010-04-01 Put in storage mode after shipping
2 2010-06-04 29 min 777 (29%) Charge from storage mode.
3 2010-08-04 servo setup 12 min 228 (8.6%)
4 2010-09-19 servo setup 14 min 330 (12.4%)
5 2010-10-10 7:30 Hover 23.09v 36 min 1172 (44%) 3.87
6 2011-04-21 n/a repair heli 14 min 232 (8.7%) Charged after repair over winter.
7 2011-04-22 ~7min hover 22.3v 

3.71-74

54 min 1871 

(71%)

8 2011-04-30 ~7min basic 23.16 

3.84-86

34 min 1074 

(40%)

9 6:30 Regular flight

Battery B

# Charge Date Flight Time Flight Style Post Flight Volts Charge Time minutes
mA Pushed In Post Charge Cell Voltage Comment
1 2010-04-01 Put in storage mode after shipping
2 2010-09-14 28 min 818 (31%) Charge from storage mode.
3 2010-10-10 7:00 Basic 

Hover

22.83 44 min 1450 (54%)
4 2010-10-10 7:00 Flying in circles. 39 min 1275 (48%) 3.82 Flyingin circles.
5 2010-11-01 —— —— —— —— —— —— Put into Storage
6 2011-04-21 —— —— —— 41 min 1274 (48%) —— Out of Storage
7 2011-04-22 ~ 7 min Hover 23v3.8 37 min 1200 

(45%)

4.19-4.20 Hardly drained it.
8 2011-04-30 ~ 7 min Basic 22.89 41 min 1379 

(52%)

4.19 Basic flight
9 6 min Regular flight

Battery C

# Charge Date Flight Time Flight Style Post Flight Voltage Charge Time minutes
mA Pushed In Post Charge Cell Voltage Comment
1 2010-04-01 Put in storage mode after shipping
2 2010-09-14 29 min 828 (31%) Charge from storage mode.
3 2010-10-10 7:00 Hovering 22.85 43 min 1419 (53%)
4 2010-11-01 —— —— —— —— —— —— Put into Storage
5 2011-04-21 —— —— —— 49 min —— —— Out of Storage
6 2011-04-22 ~10 m Hover 20.9v 

3.460v

Cannot charge it, only sees 5 cells! I applied a regular LIPO CHARGE for 85 seconds to fix it.
2011-05-06 66 min 2386 

(90%)

25.17 volts Click HERE for more info.
7 2011-mm-dd 5:20 Regular Flight
2011-mm-dd
2011-mm-dd
2011-mm-dd

Conclusions:

  • 7 minute countdown timer on the radio consumes about ~50% of battery capacity IF doing basic flying patterns.  Throttle only at mid-stick.
  • Try 10 minutes.