When it will not run on battery
Four ways this kit fails on battery — dead, resetting when Wi-Fi starts, a cell that never charges, and heat in the first few seconds — and the order to check each in. The first check is usually the answer, and a meter settles the rest.
Four symptoms
- Shield switch at ON
- Cable from TO ESP32 to the board, red to +
- Cell in LIPO BTT, red to the + mark
- Plug USB in for a minute to wake a cell whose protection has tripped
Each list starts with the check that finds the fault most often and costs least. Two faults sit behind most of them: the switch and cable between the shield and the board, and a cell that is lower than it looks.
Two readings settle it
With a meter on DC volts:
- The cell, at the back of the LIPO BTT socket. 3.0–4.2 V is a cell with something in it. Under 3.0 V, charge it. 0 V means its protection circuit has switched it off, and a charger usually wakes it.
- 3V to GND on the shield, switch ON, USB out. 3.3 V means the board is running from the cell. 0 V with a good cell means the path between them is open: the switch, the TO ESP32 cable, or the cell in the wrong socket.
A reading somewhere in between — 2.8 V on the 3V pin, say — is a cell too low to hold the rail, and from the cell to 3.3 V is why.
When to give up on a cell
Put a cell aside for good if it has swollen, if it got hot while charging, or if it will not hold above 3.0 V a day after a full charge. Take it to battery recycling rather than the bin: a lithium cell with any charge left can still start a fire when crushed.
When it does not work
Its protection circuit has switched it off, usually after it was run flat. Connect it and plug in USB: the charger normally wakes it within a few minutes. If it still reads 0 V after an hour on the charger, the cell is finished.
Something on the wiring draws too much or is shorted. The PPTC resets by itself once it cools, usually within a minute of the fault being removed. Unplug everything from the shield's terminals and add it back one wire at a time.
The cell is nearly empty and sags under load until the board resets. Charge it for an hour and read it with the read-the-cell sketch before trusting it again.
The chip this board is built around, asleep: how a battery project lasts for months.
Deep sleep and wake sources →Edit this page — content/books/esplipo/when-it-will-not-run-on-battery.mdx
Questions about this product
See what other owners have asked, and read their solutions.
ESP32 LiPo Dev Kit: 3 Boards with LiPo Charger + 3 Shields
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