DIY Solar Battery Backpack for the XTEINK X3

William Floyd — Wed, 30 Sep 2026 00:00:00 +0000

I love my XTEINK X3 (running Crosspoint), and wondered if I could make a quick and dirty solar backpack for it. I planned a better writeup but here I am anyway not letting perfect get in the way of done.

Pictures

Battery

Mold/Pour

Pour Results

Magnets

Final Result

Notes

Thin batteries are hard to get in low quantities
A thinner solar panel would be really helpful
I need to get my 3D printer running again - a printed shell + fixture to hold pogo connector would save a lot of work
Next time will avoid the epoxy itself being the rear surface - sanding flat was a lot of work, and imperfect
Charge time and efficiency are likely quite poor
Silicone tape seemed to work nicely for the battery, but robustness/actual affect untested
Getting the reed switch positioning correct is a pain when the backpack itself needs to carry it’s own magnets - maybe look at pogo-pin style switch?
A custom PCB could help reduce thickness/complexity
- As a fallback, a carrier PCB for modules would be trivial and inexpensive
I started designing a CNC case for this with the intent to do another spin, but a few things put it on the backburner:
- Space constraints are tight, case will likely still be thicker than I want
- The X3 already has excellent battery life, making this a novelty more than a useful item
- I have too many other projects in-flight

BOM

Part	Role	Notes
5V 150mA polycrystalline solar panel (~89 × 61mm)	Charging input	Close to the footprint of the X3’s back - I very much doubt 150mA claim
CN3163 mini solar charger board	Battery management	Linear solar-tracking charger, 4.4-6V in, 4.2V out
TPS63020 buck-boost module	5V output	Fixed 5V via a solder jumper, has an EN pin
303450 LiPo pouch cell, 3.7V 500mAh	Energy storage	Roughly doubles the X3’s onboard capacity
Molded reed switch (N/O)	Magnetic power switch	Enables the boost converter only when attached
4-pin 2.54mm magnetic pogo connector	Output to the X3	Matches the X3’s charging pin pitch
BSI slow-cure epoxy	Potting
Silicone tape	Battery sock	See below

I used silicone tape to seal the battery so as to prevent epoxy doing anything to the battery - I’ve not tried encasing a cell in epoxy directly, but the heat and shrink/expansions scares me and this is what I landed on that would allow some amount of squish.

Epoxy on William Floyd

DIY Solar Battery Backpack for the XTEINK X3