Best Portable Battery pack for Jetson Nano Robot

Hi! I know that there’s a jetson nano robot called the jetbot or even the kaya robot, however, I wanted to know if there were any recommendations for a portable battery that could power the Jetson Nano at a higher capacity and can also power 2 DC motors with encoders running at 9V. I’ve seen the https://www.amazon.com/dp/B076GYGR6M/ref=cm_sw_r_cp_apa_i_wC3QCb122GNTJ recommendation before, but I think that may be a bit too big for the robot. Thanks again for your consideration!

9V is actually going to be hard, unless you want to over-volt or under-volt the motors slightly.
I’d recommend over-volting the motors slightly, and making up the difference in a shorter PWM duty cycle.
Then you can go with a 3S LiPo battery (11.1V LiPo) which you can then buy in whatever size you want from any hobby / RC car store.
Then use a 5V/3A buck regulator to generate the voltage for the Jetson, and feed it through pins 2/4/6 on the 40-pin GPIO connector.
Finally, get some voltage monitor device to make sure that you don’t over-discharge the battery – when it reaches 3.3 or 3.2 Volts per cell (so, 9.9 or 9.6V) you need to immediately shut it down to avoid damaging the battery!

Here are some examples:

Reasonble battery (There are various sizes, of course): https://amzn.to/2Kny5si
Discharge warning (there are many to choose from): https://amzn.to/2YOk2Ec
Charger (again, many different models exist): https://amzn.to/2GY4pQd
Buck Converter (there are tons of others to choose from, too): https://amzn.to/2H04djz

Finally, you need a volt meter (to adjust the buck converter, and check everything in general,) a soldering iron, some wire, and a proper connector for the battery you choose.

Could you please help with this question?
The problem: we need to power additional MC (NVidia Jetson Nano) with Stereo Camera (Mint Eye) which consumes 4A of 5V.
The drone is powered by LiPo 3S battery via XT60 that connected directly to the power module.
We think about making custom power module with dc-dc step-down converter and insert in between battery and power module (which inc. in the kit).
The question: Any potential risks with the custom module and its connection between battery and main power module? Do I need to use capacitor in custom module?
Thank you