<p>Battery capacity and flight time isn't a linear relationship as a battery that is too small may not be able to supply enough current, and one that is too large may be too heavy for the motors to lift.</p>
<p>Most designers have already optimised the battery size, but for small changes you can add weight to increase flight time at the expense of performance.</p>
<p>The easy way to improve flight time is just to buy spare batteries and swap them so the extra weight stays on the ground.</p>

CC BY-SA 4.0
2024-01-02T14:10:41.583Z
2024-01-02T14:10:41.583Z
Robin Bennett
<p>DJI drones are very well balanced in the parameters playing a role. yes with a lot of work, you might be able to improve and squeeze a bit more out of it, but if you aren't doing something really wild, it's probably just a very small margin.
If you want a different performance profile, you are likely better to purpose-build from the ground up.</p>

CC BY-SA 4.0
2023-11-28T15:39:03.400Z
2023-11-28T15:39:03.400Z
ppetermann
<p>I found an interesting drone platform from the brand: Dji Drones.
From the spec sheet <a href="https://www.dji.com/global/t40/specs" rel="nofollow noreferrer">found here</a>, I realized it had some limitations... but was curious if were to modify by adding more batteries, would I increase fight time and flight speed?</p>
<p>I haven't practiced my engineering in quite sometime, but I assumed there could be a linear relationship in the process, increasing Ein should yield higher Eout. In principle?</p>
<p>Thought I'd do a bit more research and I realized a lot of factors change with such modification such as:</p>
<ul>
<li>Weight Penalty</li>
<li>Motor and Propeller Limitations</li>
<li>Flight Controller limitations</li>
<li>Weight-to-Thrust Ratio</li>
<li>Efficiency</li>
<li>Weight Distribution</li>
</ul>
<p>With proper engineering, and tuning I think such modifications should be possible?</p>

<motor><power><flight-characteristics><battery-discharge-rating><battery-capacity>
Flight properties vs Energy Storage, is it a linear relationship?
AxtII
# Flight properties vs Energy Storage, is it a linear relationship?

(Asked by: username_0 on 2023-10-23)

I found an interesting drone platform from the brand: Dji Drones.
From the spec sheet [found here](https://www.dji.com/global/t40/specs), I realized it had some limitations... but was curious if were to modify by adding more batteries, would I increase fight time and flight speed?

I haven't practiced my engineering in quite sometime, but I assumed there could be a linear relationship in the process, increasing Ein should yield higher Eout. In principle?

Thought I'd do a bit more research and I realized a lot of factors change with such modification such as:

* Weight Penalty
* Motor and Propeller Limitations
* Flight Controller limitations
* Weight-to-Thrust Ratio
* Efficiency
* Weight Distribution

With proper engineering, and tuning I think such modifications should be possible?

**Tags:** motor, power, flight-characteristics, battery-discharge-rating, battery-capacity


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## 2 answers

### Answer by username_1 on 2024-01-02. Score: 1

Battery capacity and flight time isn't a linear relationship as a battery that is too small may not be able to supply enough current, and one that is too large may be too heavy for the motors to lift.

Most designers have already optimised the battery size, but for small changes you can add weight to increase flight time at the expense of performance.

The easy way to improve flight time is just to buy spare batteries and swap them so the extra weight stays on the ground.


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### Answer by username_2 on 2023-11-28. Score: 0

DJI drones are very well balanced in the parameters playing a role. yes with a lot of work, you might be able to improve and squeeze a bit more out of it, but if you aren't doing something really wild, it's probably just a very small margin.
If you want a different performance profile, you are likely better to purpose-build from the ground up.


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