Adafruit bq25185 USB / DC / Solar Lithium Ion/Polymer charger
100 units will be available shortly.
We're always looking for better ways to keep projects portable, and having a convenient way to charge your battery ensures your project stays powered no matter the available source. The Adafruit bq25185 USB/DC/Solar Charger Board is a versatile charging solution that supports multiple battery chemistries (LiPoly, LiIon, or LiFePO4), adjustable charge rates (250mA, 500mA, or 1A), and various power sources (USB, DC, or solar). It’s an excellent upgrade from MCP73833 or MCP73831-based charger boards, offering greater flexibility and value.
To maximize its potential, we've designed a feature-packed breakout board with the most useful capabilities:
Power and Charging Options
- USB Type-C Connector – Includes 5.1k CC resistors for compatibility with any computer or power adapter, providing 5V and up to 1A.
- Separate DC or Solar Input – Two side pads allow for a 5–18V power source, such as a DC adapter or solar panel. When using solar, the chip optimizes current draw to prevent voltage dips, providing near-MPPT capability without extra components.
- Adjustable Charge Rate – Default charge rate is 1A, but you can adjust it to 500mA or 250mA by modifying the onboard jumpers.
Battery Compatibility and Power Management
- Supports Multiple Battery Chemistries – Defaults to 3.7V nominal / 4.2V max for LiPoly/LiIon, but can be adjusted to 3.2V / 3.65V for LiFePO4 batteries via jumpers.
- Smart Power Path Management – If the circuit is drawing power while the charger is connected, it will prioritize the external power source while any excess current charges the battery. This prevents unnecessary battery cycling, extending battery life. The chip also allows for up to 3A current spikes from the battery to the load.
- Regulated Load Output (4.5V max) – The load output will never exceed 4.5V, regardless of the input voltage. However, high current and voltage inputs may cause heat buildup, leading to thermal throttling.
Additional Features
- Three Status LEDs – Orange: Charging, Red: Fault, Green: Power Good. Charge/fault pins are also accessible on breakout pads.
- Thermistor Support – By cutting the TH trace and adding a 10K thermistor, you can regulate the charge rate based on battery temperature.
- Chip Enable Pin – Allows you to disable the charger when needed.
- Mounting Holes – For secure installation in your project.
Quick Start Guide
Simply adjust any jumpers as needed, connect your battery to the BATT port, and wire your circuit to the LOAD port. Keep in mind that LOAD voltage ranges from 3.0V (low battery) to 4.5V max. If required, you can monitor both battery and load voltage via secondary pads on the right side.
Using with Solar Panels
For solar charging, use a 5–7V solar panel. You can either cut the connector and wire it directly or use a 2.1mm adapter cable + terminal block for easy connection to the DC input.
Looking for More Power?
If you need a higher charge current or an onboard DC jack, check out the bq24074 charger board, which supports up to 1.5A charging and includes a built-in 2.1mm DC plug.
The Adafruit bq25185 USB / DC / Solar Lithium Ion/Polymer charger appears in the following collections:
SKU AF-6091
by Adafruit
