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Battery capacity, Battery capacity (continued), Recommended guidelines for battery capacity – Spektrum SPMAR9100 User Manual

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Spektrum AR9100

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Spektrum AR9100

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It’s important to select a battery(s) that has more than adequate capacity

to provide the necessary flight time. Our staff has been recording in-flight

data to determine typical current consumption of aircraft in flight.

Following are two graphs that illustrate the in-flight current draw of the

radio system.
Note: Current draws may vary depending on your servos, installation and flying style.

The following setup is shown as a worst case scenario indicative of some

aerobatic pilots’ setups. It is not recommended to use this setup without

proper voltage regulation for your servos.
Airplane - 40% YAK

Servos - 9-JR8711’s 1-8317 (throttle)

Batteries - Two 4000mAh 2-cell 7.4-volt LiPo’s

Regulator - none

Note: JR8711’s and 8317’s are rated at a maximum of 6-volt 5-cell use.

Using higher voltages will void the warranty.

Engine - DA150

Weight - 40 lbs

Flight envelope - Hard 3D

Average current - 2.62 amps

Peak current - 17.8 amps

Milliamps used per 10 minute flight - 435mAh

Battery Capacity

File: JasonNoll.FDR Session:All Sessions

Seconds

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300

250

200

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100

50

Pa

ckA

mp

s_

A

18

17

16

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13

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11

10

9

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7

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0

PackAmps_A: Min 0.00 Max 17.80 Avg 2.62

450

400

0

In the example above, the average current was 2.62 amps, which

calculates to 435mAh per 10 minutes (typical flight length). It’s recommended

that only 60% of the available capacity be used to ensure plenty of reserve

battery capacity. In this example using two 4000mAh batteries (8000mAh total

capacity) x 60%= 4800mAh (available usable capacity) divided by the

capacity used per 10-minute flight, 435mAh would allow up to 11 flights, of

10 minutes each.

Airplane - 33% Sukhoi

Servos - 7-JR8611’s 1-8317 (throttle)

Batteries - 1- 4000mAh 2-cell 7.4-volt LiPo

Regulator - 6 volt

Engine - DA100

Weight - 26 lbs

Flight envelope - Moderate 3D

Average current - .82 amps

Peak current - 6.92 amps

Milliamps used per 10-minute flight - 137mAh

Battery Capacity (continued)

File: sukhio Session:All Sessions

PackAmps_A: Min 0.00 Max 6.92 Avg 0.82

Seconds

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350

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250

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100

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Pa

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6.5

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1.5

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Recommended Guidelines for Battery Capacity

40-45% Aerobatic aircraft w/ 9-12 high-current servos: 4000–8000mAh
33-35% Aerobatic aircraft w/ 7-10 high-current servos: 3000–6000mAh
25% Quarter Scale Aerobatic aircraft w/ 5-7 high-current servos:

2000–4000mAh

Jets - BVM Super BANDIT, F86, Euro Sport, etc.: 3000–6000mAh
Giant-Scale Jets - BVM Ultra Bandit:4000–8000mAh
Scale aircraft - The varieties of scale aircraft and the accessories they use

vary tremendously making it difficult to give capacity recommendations for

these types of aircraft. Using the previously mentioned aerobatic guidelines

relative to the size and number of servos used will provide a conservative

capacity for your scale aircraft. As always, check battery charge condition

before each flight.