Pi-Ener-lite: A $35 18650 UPS for Raspberry Pi Zero

Battery backup for a Raspberry Pi Zero usually costs you the GPIO header, which is a bad trade when the header is the whole reason you picked a Zero. ACE Design Studio's Pi-Ener-lite, covered by CNX Software on August 17, 2026, takes a different route: it bolts to the underside of the board and communicates through seven spring-loaded pogo pins, so the 40-pin header stays open for whatever HAT your project actually needs.

• Sells for $35 on Tindie plus shipping from $9, and includes 3D-printed enclosure parts
• Takes one standard flat-top 18650 lithium-ion cell; charges at 1A over USB Type-C and outputs 2.5A at 5.1V
• Carries a DS1307 real-time clock with CR1220 backup and a CW2015 fuel gauge accurate to plus or minus 2% state of charge
• Connects through seven pogo pins rather than the GPIO header, leaving it free for other HATs

What the Pi-Ener-lite Board Actually Does

Strip away the marketing and a UPS board for a single board computer has one job: keep the rails up when the wall power goes away, and tell the operating system how much runway is left. The Pi-Ener-lite does both. It supports simultaneous charge and discharge, so the Pi keeps running while the cell tops up, and it flips to battery automatically when the USB-C input drops out. Output is rated at 2.5A at 5.1V, which is comfortably above what a Pi Zero 2 W draws even under sustained load with a camera attached.

The fuel gauge is the part hobbyist power boards most often skip. A CW2015 chip reports state of charge to within about 2% and voltage to within 3mV over I2C, which is the difference between a script that can gracefully shut down at 10% and a project that just dies mid-write and corrupts its card. Protection circuitry covers overcharge, over-discharge, overcurrent, and short circuit — the standard set, but worth confirming on any board you plan to leave unattended with a lithium cell in it.

Why the Pogo Pin Design Matters for Raspberry Pi Zero Projects

Most Raspberry Pi UPS HATs stack on top of the 40-pin header and end the conversation there. On a Pi Zero, where the whole appeal is a 65mm board you can hide inside something, giving up the header to a power module often kills the build. Seven pogo pins carrying both power and I2C is a neat sidestep: the battery board becomes a base plate rather than a passenger, and your e-ink display, sensor breakout, or LoRa radio still has somewhere to go.

That design choice puts it in direct conversation with the wave of compact Pi Zero builds we keep covering, from the PiShot pocket camera to the Secluso privacy security camera. Both are exactly the kind of project that wants a battery and a spare header at the same time.

What Does the Pi-Ener-lite Cost and What Is in the Box?

Thirty-five dollars, sold through Tindie, with shipping starting at $9. The package covers the UPS board and 3D-printed enclosure parts. It does not include the Raspberry Pi Zero, the 18650 cell, or the CR1220 coin cell for the real-time clock, so budget another few dollars and a trip to a battery supplier before the project is actually complete. Final board dimensions had not been published at the time of CNX Software's write-up.

Is It Worth It Over a Plain Power Bank?

A USB power bank is cheaper and needs no soldering, but it cannot tell your Pi anything. It will not hold a clock through a cold boot, it will not report remaining charge, and many will cut out entirely during the low-draw moments when a Zero idles. A board with a fuel gauge and an RTC turns a portable project into one that knows what time it is and how much time it has left — which is the whole point of a real-time clock on a board with no battery-backed clock of its own.

For anyone assembling a shelf of always-on Pi hardware, this fits neatly alongside the rest of our mini computer and SBC coverage, and pairs well with today's Raspberry Pi power supply and UPS guide if you are still deciding how to feed the rest of your fleet.

Sources: CNX Software — August 17, 2026; ACE Design Studio on Tindie — accessed August 17, 2026.