# Taranis Q X7 Battery Run Time

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## Basic Calculation

• Wh = Watts x time in hours
• h = Wh ÷ W
• Wh – Watt-hour, a unit of capacity
• h – hours
• W – Watt
• W = V x A
• V – Voltage
• A – Ampere
• mA – miliampere, 1000 mA = 1A

## Battery Options

• Battery Clip 6 x AA
• 7.2 V NiMH 2400 mAh • Battery Pack
• Operating Voltage Range
• 6 to 15 V
• 2S, 3S Lipos are acceptable
• Maximum Battery Dimensions
• 93.4 x 57.9 x 16.1 mm
(battery clip with batteries measured using vernier calipers)
• Very tight fit, go a couple of mm smaller in each dimension

## Run Time

• Power Used ↑     Time ↓
• Watts (W) = V x A
• Tx, LCD, Modules
• Battery Capacity ↑     Time ↑
• Watt Hours (Wh) = W x Time(h)
= V x A x h= V x Ah (printed on batteries)

## Tested Battery Capacities

• Battery Pack
• 7.2 V x 0.8 Ah = 5.76 Wh
• Battery Clip
• 7.2 V x 2.4 Ah = 17.28 Wh
• Run time 3 x Battery Pack?
• Lipo 3S
• 11.1 V x 0.85 mAh = 9.44 Wh
• Run time 1.6 x Battery Pack?

## Run Time Tests

### Method

• LCD backlight brightness 100%, always on
• SD Card logs on
• No external module used or music playing
• Left on till drained
• 6 V for NiMH & 9.4 V for 3S LiPo

### Results

#### Discharge Curves #### Run Times

• 800 mAh NiMH battery pack (5.76 Wh)
• 4 hours 5 minutes
• 850 mAh 3S Lipo (9.44 Wh)
• 7 hours 15 minutes
• 1.8 x battery pack time (predicted 1.6)
• 2400 mAh NiMH batteries in the battery clip (17.28 Wh)
• 13 hours 5 minutes
• 3.2 x battery pack time (predicted 3)

#### Battery Capacity vs. Time Graph The battery capacity vs. time graph enables us to determine the power consumed by the transmitter which is 1.3 Watts.

#### Calculation – Battery Capacity Required For A Desired Run Time

• If you want 10 hours
• Capacity Required = 1.3 Watts x run time hours required
• 1.3 W x 10 h = 13 Wh
• NiMH 7.2 V
• 13 Wh / 7.2 V = 1.8 Ah = 1800mAh

#### Reference – Battery Capacity Required Per Hour of Run Time

• 1 hours requires 1.3 Wh
• NiMH 7.2 V – 180 mAh per hour
• 2S LiPo 7.4 V – 176 mAh (180 mAh) per hour
• 3S LiPo 11.1 V – 117 mAh (120 mAh) per hour

#### Calculation – Run Time Estimated Based On Battery Capacity

• If you have 1000 mAh NiMH
• Capacity = 7.2 V x 1 Ah = 7.2 Wh
• Run Time Estimated = Capacity / 1.3 W
• 7.2 Wh/1.3 W = 5.5 h

#### Reference – Run Time Estimated Per Wh or Per 1000 mAh

• 1.3 Wh of capacity provides 1 hour of run time
• 1 Wh of capacity provides 0.76 of an hour of run time
• 1000 mAh provides different hours of run time based on voltage
• NiMH 7.2 V – 5.5 hours per 1000 mAh
• 2S LiPo 7.4 V – 5.6 hours per 1000 mAh
• 3S LiPo 11.1 V – 8.4 hours per 1000 mAh

## Formulas For The Taranis Q X7

### Battery Capacity Required

• Wh = 1.3 W x h
h – run time required in hours

### Run Time Estimate

• h = Wh ÷ 1.3 W
Wh – battery capacity being used