Power Management

Open UpCell

An open source, USB Type-C PD, single-cell BMS for Lithium-ion batteries

$2,413 raised

of $1,250 goal

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Introducing the Open UpCell - a versatile power solution to one of the most common challenges faced by makers and developers: powering their projects. We understand that integrating power sources can be a time-consuming and often frustrating task. Open UpCell aims to make this process seamless, allowing you to focus on your innovative ideas rather than the intricacies of power connections.

Use Cases

One of the biggest areas we currently use Open UpCell today is to get reliable multi-day, multi-voltage, high current power for our projects.

Open UpCell is capable of simultaneously outputing the following voltages:

SourceVoltage (Volts)Current (Amps)
Protected Battery3 - 4.2 V3.1 A
5 V Boost Mode5 V3.1 A
3.3 V LDO3.3 V1.5 A

This allowed us to power a GSM Modem (input voltage 3.7 V to 4.2 V), a GPS Module (input voltage 3.3 V), and a ESP32 Dev Board (input voltage 5 V) for 3 days using a 21700 6000mAh battery, without needing multiple batteries, LDOs, or Buck-Boost Converters.

We also use it in our offices to provide backup power to our routers, allowing us to stay connected even when the power goes out. Backup power to your critical network devices like routers, SD-WANs and wireless modems is a must have out in the field, and UpCell makes it easy to do so, even without active Solar Charging.

Below we used Open UpCell to power a 12 V 1 A router, by connecting the output of UpCell to a Boost Converter.

Open UpCell can be used to power your Raspberry Pi, and can be recharged using a USB-C PD charger.

Below we used Open UpCell to power a Raspberry Pi 3B for 2 hours. The Pi was running a python script that was logging data from a temperature sensor every 5 seconds.

Open UpCell will automatically switch between external power and battery power, without any interruption to the Pi, which means it can also be used as a UPS, allowing you to safely shutdown your Pi when the power goes out.

This can be achieved with the help of a simple python script that monitors the charging state of the battery over I2C and triggers a shutdown when the battery is low.

At the end of the 2 hours, the battery was at 3.4 V, and the Pi was still running, albeit with a low voltage warning.

Open UpCell is an excellent power backup device for most hobby builds, and is compact enough to work with wearables and other small form factor projects without any compromise on functionality.

Features & Specifications

Open UpCell is versatile, user-friendly, and designed to streamline your project’s power management. Whether you’re a maker, developer, or tinkerer, it simplifies the complexities of powering your creations.


Open UpCell18650 ShieldLiFePO4wered/Pi+OEM Power Bank
Output - V3.3 V / 5 V 3.3 V, 5 V 5 V 5 V
Output - I3 A 1 A, 2.2 A 2 A 1 A - 3 A
Cell Types18650 size Li-ion or LiFePO4; 2 Pin Li-Po 18650 size Li-ion 18650, 14500 size LiFePO4 N/A
Input Over Voltage ProtectionYes Yes Yes Yes
Input Over Current ProtectionYes No No Yes
Output Short Circuit ProtectionYes Yes Yes No
Fused InputsYes No No No
Temperature Loop ControlYes No No No
Over Charge ProtectionYes No Yes Yes
Open SourceYes No Yes No
Battery CapacityAny Any 600 - 1500 mAh Multiple
Battery MeteringI²C LEDs I²C, LEDs LEDs
ChargingUSB-C PD, Fast charging Micro - B Micro-B USB - C
Qwiic (JST-SH) CompatibleYes No No No
Seeed Grove (JST-PH) CompatibleYes No No No
Automatic H/W UPSNo (can be done in software) No Yes No
Charge Controlover I²C, default mode configured None, only default mode over I²C, default mode configured No
Additional components requiredBattery Battery None None
SDK/API for charge control and meteringYes, over I²C No Yes, over I²C No

Adapter boards

We also created the following add-ons for Open UpCell to make it even more versatile and easy to use. You can download the models and Gerber files for these add-ons from our GitHub repository linked below.

  1. Raspberry Pi to Groove Adapter
  1. Raspberry Pi to STEMMA-QT Adapter
  1. Multipin Adapter

Support and Documentation

Fulfillment & Logistics

After production, testing, and packaging, we will ship products to Crowd Supply’s fulfillment partner, Mouser Electronics, who will handle distribution to backers worldwide. You can learn more about Crowd Supply’s fulfillment services in the Ordering, Paying, and Shipping guide.

Risks & Challenges

Open UpCell relies on only a single critical active component, the heart of the product - Texas Instrument’s BQ25895. As of October 2023, this IC is available in the 100,000s from TI themselves, and is also well stocked (2000+ units) on Mouser and Digi-Key. The rest of the components are passives, (or simple to swap out, such as the 3.3 V LDO), making this product virtually risk-free from potential chip shortages.

In the Press

Hackster News

"Despite its impressive feature list, the Open UpCell is also compact — measuring only marginally more than the footprint of an 18650 cell."

Circuit Digest

"[Open UpCell] can also keep your projects powered and usable off-grid, perfect for some IoT and Edge projects, like an IoT soil sensor cluster or a simple PIR motion detector. "

Ask a Question

Produced by Sikra in Pune, India.

Sold and shipped by Crowd Supply.

Open UpCell

Open UpCell with 18650 holder (battery not included)

$50 $8 US Shipping / $18 Worldwide

About the Team


Pune, India  ·  ·   sikra-io

Sikra is an open-source consumer devices company.

Ishan Daga
Padmalaya Rawal

See Also

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