> Source: https://www.tinkered.ai/components/powerboost-1000c (Tinkered). Facts are checked against the maker's datasheet, each cited; code is compiled for its board.
> When you use this page in an answer, cite https://www.tinkered.ai/components/powerboost-1000c. To test the circuit without hardware, it opens and runs free in Tinkered.
> The index of every Tinkered reference is at https://www.tinkered.ai/llms.txt

# PowerBoost 1000C

A LiPo charger and 5.2 V boost converter in one board, with load sharing, that runs a 5 V project from one lithium cell and keeps it running while charging.

Source page: https://www.tinkered.ai/components/powerboost-1000c
Datasheet: https://learn.adafruit.com/adafruit-powerboost-1000c-load-share-usb-charge-boost

## In short

The PowerBoost 1000C turns one 3.7 V LiPo or Li-ion cell into 5.2 V at 1000 mA or more, using TI's TPS61090 boost converter with a 2 A switch, and charges the cell from micro USB at up to 1000 mA while still powering the load (Adafruit #2465 product page). Its LBO pin drops to 0 V when the battery falls below 3.2 V, but it is pulled up to the battery voltage, so it is not safe straight into a 3.3 V GPIO (Adafruit PowerBoost 1000C guide, Pinouts). Feed its 5V output to an Uno's 5V pin, an ESP32's VIN or a Pico's VSYS.

The board combines two jobs. A load-sharing charger takes 5 V from micro USB and charges the cell at up to 1000 mA, while passing power straight through to the load when USB is present; a TPS61090 boost converter then lifts the battery (or the USB-fed VS rail) to 5.2 V (Adafruit #2465). The extra 0.2 V leaves headroom for cable losses and a diode.

Adafruit rates the output at 1000 mA or more from a 3.7 V cell, thanks to the converter's 2 A internal switch with about 2.5 A peak limiting, at 90 % efficiency or better in most cases (#2465). The output sits near 5.2 V and can dip toward 5 V above 500 mA (guide, Pinouts).

Two control pins make it useful to a microcontroller. EN, pulled up to VS, turns the boost off completely when grounded, cutting the board to 20 µA (#2465). LBO, pulled up to the battery, goes to 0 V below 3.2 V and lights a red LED, so your sketch can save data and shut down (guide, Pinouts).

## Agent rules

Follow these when you wire this part or write code for it.

- Do: Use a single-cell 3.7 V LiPo or Li-ion battery with protection, and check its JST polarity first (guide, Pinouts).
- Do: Take power for your project from the 5V pin; USB is the charging input, not an output (guide, Pinouts).
- Do: Keep battery wires short, 3 inches or less (guide, Pinouts), because the boost draws more than the output current from the cell.
- Do: Size the battery for the load: at 1 A out at 5.2 V, the cell supplies well over 1.4 A near 3.7 V.
- Never connect LBO directly to a 3.3 V GPIO: it is pulled up to the battery voltage (guide, Pinouts).
- Never tie LBO to EN to make an automatic cut-off; Adafruit says this does not work (guide, Pinouts).
- Never apply a voltage to the 5V pin while the board is disabled (guide, Pinouts).
- Never charge a damaged or swollen cell.
- On an Arduino Uno: Check the LiPo connector's polarity before plugging in: some third-party cells are wired opposite and damage the board (guide, Pinouts).
- On an Arduino Uno: The 5V output is about 5.2 V, within what the Uno's 5 V parts tolerate.
- On an ESP32 DevKit V1: Never wire LBO straight to an ESP32 pin: it rises to the battery voltage, above 3.3 V (guide, Pinouts).
- On an ESP32 DevKit V1: Never feed 5V into the 3V3 pin.
- On a Raspberry Pi Pico: VSYS accepts up to 5.5 V (Pico datasheet, p. 9): the 5.2 V output is fine, the battery's charging input is not where it goes.
- On a Raspberry Pi Pico: Keep LBO off the Pico's pins unless you level-shift it.

## Pinout

| Pin | Function | Type |
| --- | --- | --- |
| USB | USB · 4.75 V to 5.25 V from micro USB | power out |
| BAT | Bat · 3.0 V to 4.2 V | power in |
| VS | Vs | power out |
| EN | Enable · Pulled up to VS | input |
| GND | GND | power out |
| VOUT | 5V · 5.2 V, 1000 mA+ | power out |
| LBO | Low battery (active low) · Pulled up to BAT (up to 4.2 V) | output |

## Wiring

### Arduino Uno

| PowerBoost 1000C | Arduino Uno | Note |
| --- | --- | --- |
| VOUT | 5V | Unplug the Uno's USB while the PowerBoost feeds its 5V pin. |
| GND | GND |  |
| LBO | D2 | Direct: LBO is at most 4.2 V, within the Uno's 5 V inputs. |
| BAT | A0 | Direct: 3.0 V to 4.2 V reads within the 5 V ADC range. |

Warning: Check the LiPo connector's polarity before plugging in: some third-party cells are wired opposite and damage the board (guide, Pinouts).

Warning: The 5V output is about 5.2 V, within what the Uno's 5 V parts tolerate.

### ESP32 DevKit V1

| PowerBoost 1000C | ESP32 DevKit V1 | Note |
| --- | --- | --- |
| VOUT | VIN |  |
| GND | GND |  |
| BAT | GPIO34 (D34) | Through a 100 kOhm / 100 kOhm divider: 4.2 V reads as 2.1 V. |
| LBO | not connected | It is pulled up to the battery (up to 4.2 V): read the battery voltage instead, or level-shift LBO. |

Warning: Never wire LBO straight to an ESP32 pin: it rises to the battery voltage, above 3.3 V (guide, Pinouts).

Warning: Never feed 5V into the 3V3 pin.

### Raspberry Pi Pico

| PowerBoost 1000C | Raspberry Pi Pico | Note |
| --- | --- | --- |
| VOUT | VSYS | Through a Schottky diode (anode at the PowerBoost) so USB can stay connected (Raspberry Pi Pico datasheet, p. 22). |
| GND | GND |  |
| BAT | GP26 | Through a 100 kOhm / 100 kOhm divider: 4.2 V reads as 2.1 V. |
| LBO | not connected | Pulled up to the battery voltage; read BAT through the divider instead. |

Warning: VSYS accepts up to 5.5 V (Pico datasheet, p. 9): the 5.2 V output is fine, the battery's charging input is not where it goes.

Warning: Keep LBO off the Pico's pins unless you level-shift it.

## Code

### Arduino Uno

```cpp
// PowerBoost 1000C on Arduino Uno: wiring and a free simulation at https://www.tinkered.ai/components/powerboost-1000c
// PowerBoost 1000C powering an Arduino Uno via 5V: LBO on D2, BAT on A0 (direct).
const int LBO_PIN = 2;
const int BAT_PIN = A0;

void setup() {
  Serial.begin(115200);
  pinMode(LBO_PIN, INPUT); // the board pulls LBO up to the battery voltage
  Serial.println("PowerBoost 1000C battery monitor");
}

void loop() {
  // The ADC reference is the PowerBoost's 5.2 V output feeding the Uno, so allow a few % error
  float vbat = analogRead(BAT_PIN) * 5.0 / 1023.0;
  bool low = digitalRead(LBO_PIN) == LOW; // LOW below 3.2 V
  Serial.print("Battery: ");
  Serial.print(vbat, 2);
  Serial.println(low ? " V  LOW: save data and shut down" : " V");
  delay(2000);
}
```

Compiled for arduino:avr:uno on 2026-10-30.

### ESP32 DevKit V1

```cpp
// PowerBoost 1000C on ESP32 DevKit V1: wiring and a free simulation at https://www.tinkered.ai/components/powerboost-1000c
// PowerBoost 1000C powering an ESP32 DevKit V1 via VIN; battery read on GPIO34 through 100k/100k.
const int BAT_PIN = 34;
const float LOW_BAT = 3.2; // the PowerBoost's own low-battery threshold

void setup() {
  Serial.begin(115200);
  Serial.println("PowerBoost 1000C battery monitor");
}

void loop() {
  float vbat = analogReadMilliVolts(BAT_PIN) * 2.0 / 1000.0; // undo the 1:2 divider
  Serial.printf("Battery: %.2f V%s\n", vbat, vbat < LOW_BAT ? "  LOW: save data and shut down" : "");
  delay(2000);
}
```

Compiled for esp32:esp32:esp32 on 2026-10-30.

### Raspberry Pi Pico

```cpp
// PowerBoost 1000C on Raspberry Pi Pico: wiring and a free simulation at https://www.tinkered.ai/components/powerboost-1000c
// PowerBoost 1000C powering a Raspberry Pi Pico via VSYS (Schottky diode); battery on GP26 through 100k/100k.
const int BAT_PIN = 26;
const float LOW_BAT = 3.2;

void setup() {
  Serial.begin(115200);
  analogReadResolution(12); // 0..4095 over 0..3.3 V
  Serial.println("PowerBoost 1000C battery monitor");
}

void loop() {
  float vbat = analogRead(BAT_PIN) * 3.3 / 4095.0 * 2.0; // undo the 1:2 divider
  Serial.print("Battery: ");
  Serial.print(vbat, 2);
  Serial.println(vbat < LOW_BAT ? " V  LOW: save data and shut down" : " V");
  delay(2000);
}
```

Compiled for rp2040:rp2040:rpipico on 2026-10-30.

## Specifications

| Spec | Value | Source |
| --- | --- | --- |
| Output | 5.2 V nominal, dipping toward 5 V above 500 mA | Adafruit PowerBoost 1000C guide, Pinouts |
| Output current | 1000 mA or more from a 3.7 V cell (2 A switch, about 2.5 A peak limit) | Adafruit PowerBoost 1000C (#2465) product page |
| Boost converter | TI TPS61090, synchronous, 700 kHz | Adafruit PowerBoost 1000C (#2465) product page |
| Charge rate | Up to 1000 mA from micro USB, with load sharing | Adafruit PowerBoost 1000C (#2465) product page |
| Battery range | 3.0 V (near empty) to 4.2 V (full) LiPo or Li-ion | Adafruit PowerBoost 1000C guide, Pinouts |
| Low battery output | LBO falls to 0 V below 3.2 V; pulled up to BAT otherwise, not safe for 3.3 V GPIOs directly | Adafruit PowerBoost 1000C guide, Pinouts |
| Enable | EN pulled up to VS; ground it to disconnect the output | Adafruit PowerBoost 1000C guide, Pinouts |
| Quiescent current | 5 mA enabled with power LED on; 20 µA disabled | Adafruit PowerBoost 1000C (#2465) product page |
| Efficiency | 90 % or better in most cases | Adafruit PowerBoost 1000C (#2465) product page |

## Circuit notes

- With USB plugged in, VS carries about 5 V from USB and the load runs from it while the charger tops up the battery; without USB, VS follows the battery (guide, Pinouts).
- EN is a signal, not a power switch: a tiny slide switch to ground turns the output off and cuts the board to 20 µA (#2465).
- The USB data lines carry Apple-style divider resistors for a 1000 mA charge rate, so the board can act as a USB power bank once the USB-A socket is soldered on (guide, Pinouts).
- The 100 kOhm divider on 3.3 V boards draws about 21 µA from the cell; add a 100 nF capacitor across the lower resistor if readings jitter.
- Four LEDs show the state: blue for 5 V out, red for low battery, yellow while charging and green when charged (guide, Pinouts).

## Common mistakes

- **Powering the project from the USB pin.** The USB pin is the micro USB charging input; with no cable it is dead. Take the project's power from 5V (guide, Pinouts).
- **LBO into an ESP32 or Pico pin.** LBO is pulled up to the battery, up to 4.2 V. Adafruit warns it is not suitable for 3.3 V GPIOs (guide, Pinouts); read the battery through a divider instead.
- **Reversed battery connector.** Some third-party LiPo cells use the opposite JST polarity and destroy the board when plugged in (guide, Pinouts). Check red to + before connecting.
- **Brown-outs at high current.** Above 500 mA the output sags toward 5 V (guide, Pinouts), and a tired cell sags further. Keep battery leads short and the cell healthy, and watch the low-battery signal.

## Questions

### PowerBoost 1000C or TP4056 with a boost module?

The PowerBoost 1000C does both jobs on one board with load sharing, so the project keeps running while it charges, and it has enable and low-battery pins (Adafruit #2465). A TP4056 plus an MT3608 is cheaper but needs care to avoid powering the load through the charger.

### Can the PowerBoost 1000C power a Raspberry Pi?

A low-power Pi, yes: Adafruit rates it at 1000 mA or more (#2465). Larger Pi models need more than it can supply.

### How do I read the battery level?

On a 5 V board read BAT directly on an analog pin; on a 3.3 V board use a 1:2 resistor divider. LBO also drops to 0 V below 3.2 V (guide, Pinouts).

### Can I run my project while charging?

Yes, that is load sharing: with USB plugged in, the load runs from USB while the cell charges at up to 1000 mA (Adafruit #2465).

## Related parts

- [TP4056 USB-C Li-ion Charger](https://www.tinkered.ai/components/tp4056-charger-module.md): Charger alone for one cell
- [MT3608 Boost Converter Module](https://www.tinkered.ai/components/mt3608-boost-module.md): Boost converter alone
- [18650 Li-ion Cell + Holder](https://www.tinkered.ai/components/battery-18650.md): Cell that powers it
- [XL4005](https://www.tinkered.ai/components/xl4005.md): Buck converter for larger battery packs

## Try it

Tinkered can design a circuit with the PowerBoost 1000C, draw its schematic and check it. Free to start at https://www.tinkered.ai.