Since I’ve an old 1S (3.7V/2500mAh) Li-Ion battery in hand, I inserted it correctly into the battery compartment, and connected a power bank to the Micro USB port through a short Android charging cable. Is it a good and worthwhile pick? Let me recite my observances!Īs you might think, the $3 (plus shipping) shield comes without a 18650 Li-Ion battery. Following some previous regretful experience with some other portable power packs and RPi, I decided to buy, try, and modify this particular 18650 battery shield. Really what I needed is a compact solar USB power pack for an upcoming Raspberry Pi project. The 3.3VDC supply is derived from the 3.7V-4.2VDC Li-Ion battery output (not from the 5VDC output). The second channel output, marked as 3V but 3.3V on the dot, is supplied by the parallel combination of three positive voltage regulator chips. In the shield, the dc- dc boost converter chip is used to deliver 5VDC (actually 4.99V) through the USB ‘A’ socket and 5V male-header points, generated from the available 3.7V-4.2VDC Li-Ion battery output. Refer to the annotated image provided below (and the table next to it) to get a deep insight on the underlying electronics.Ĥ.5A current mode dc-dc boost converter chipĪnd, a couple of recommended web links to view/download related datasheets: The background electronics are a clever blend of three requisite circuits, that is to say, a lithium-ion battery charger circuitry, a battery protection circuitry, and a dc-dc boost converter circuitry.

The Micro USB port (labeled as Input) is the battery charger (5V/500mA) input socket. As you can see, almost all key parts are soldered neatly on the bottom side of the printed circuit board. Here’s the bottom view of the 18650 shield. Battery Protection Mechanism: Battery Overcharge & Deep Discharge.System Status Indicators: Battery Charging & Battery Charged LEDs.Power Supply Output: Switched 5VDC via USB type A port, 3x 5VDC (up to 4A) connectors, and 3x 3VDC (up to 1A).Battery Charging Input: 5V/500mA typical via Micro USB port.It also includes a standard USB ‘A’ female connector, and one power on/off switch for that connector atop. The pictured shield holds a 18650 Li-Ion battery holder at the top of the circuit board, which can accommodate an ‘unprotected’ single-cell lithium-ion battery. The latest addition to my collection is a cheap portable power supply module labeled by its seller as “18650 Battery Shield (V3) for Raspberry Pi & Arduino”. There are countless variants of portable power supply devices that can be used to power up most microcontroller-based projects on a variety of websites. Recently I bought a few portable power supply devices to run my little microcontroller projects.

Fritzing connect arduino raspberry pi