What is Toilet Tank Battery Mounting in FPV Drones – Installing LiPo Sideway

by Oscar

In the world of FPV drone, there’s a curious mounting style that’s gained attention: the “toilet tank” battery mounting. This method involves placing the battery sideways on the drone, rather than the conventional front-to-back orientation. Let’s discuss its impact on quadcopter dynamics in this article, the benefits and drawback of toilet tank battery mounting.

Some of the links on this page are affiliate links. I receive a commission (at no extra cost to you) if you make a purchase after clicking on one of these affiliate links. This helps support the free content for the community on this website. Please read our Affiliate Link Policy for more information.

The Concept of Toilet Tank Mounting

Toilet tank mounting alters the mass distribution of the FPV drone. Imagine a cylinder: it rotates easily around one axis but is more sluggish around the other due to the mass’s distribution. Similarly, when the battery, a significant part of a drone’s mass, is mounted sideways (toilet tank style), it changes the drone’s responsiveness. Specifically, it enhances responsiveness on the pitch axis while slightly reducing it on the roll axis. This trade-off in axis responsiveness is a matter of personal preference.

Impact on Quadcopter Dynamics

When you mount the battery in a toilet tank style, you’re essentially trading responsiveness between the roll and pitch axes. A drone with a front-to-back battery will be more responsive in rolling but less so in pitching, and vice versa for the toilet tank style. This difference in responsiveness stems from how the mass is spread across the drone’s frame.

Practical Advantages

Beyond the change in flight dynamics, toilet tank mounting offers practical benefits. For compact racing frames with a short body, fitting the battery on top can be challenging. This problem exacerbates if there’s a GoPro camera mounted in the front, as the battery can press against and potentially damage it. Mounting the battery sideways addresses this issue, allowing for a more compact frame design without risking damage to the camera.

However, it’s crucial to note that the proximity of the battery to the props could be a concern, depending on the frame design. In some cases, it might increase the risk of prop strikes on the battery.

Tuning and Performance

While it’s true that PID (Proportional, Integral, Derivative) tuning can compensate for different mass distributions to an extent, it’s more about how the quadcopter needs to work harder to achieve the same rate of rotation on certain axes. This necessity might result in different PID settings for each orientation. Generally speaking, the axis that’s harder to rotate will require higher PID gains.

Personal Preference and Practicality

Ultimately, whether or not toilet tank mounting “flies better” is subjective. Some pilots might prefer the altered mass distribution and its impact on flight characteristics. However, I believe the choice often boils down to practical reasons like fitting the battery more comfortably and avoiding damage to other components.


Toilet tank mounting in FPV drones is more than just a trend; it’s a practical approach that impacts the drone’s responsiveness and form factor. Whether for performance, convenience, or necessity, it presents an interesting alternative to traditional battery mounting methods. As with many aspects of drone flying, it ultimately comes down to personal preference and the specific requirements of your build.

Leave a Comment

By using this form, you agree with the storage and handling of your data by this website. Note that all comments are held for moderation before appearing.

1 comment

cg 16th January 2024 - 3:43 am

its mainly plastering a wrong formfactor, i use it for 65 and 75mm whoops.
the best would be well sized square shaped batteries