Battery and power
What the Beepy draws, why it barely charges while running, how to measure drain from the device, and what PennyOS turns off for you.
What it draws
| State | Current | On the 2000 mAh cell |
|---|---|---|
| On and idle, keyboard light off | about 0.20 A | roughly ten hours |
| On and idle, keyboard light on | about 0.25 A | roughly eight hours |
| Shut down | about 0.005 A | weeks |
These were measured on one device with a USB meter and will vary with Wi-Fi activity and the apps you use.
Measure it on the device
Settings > Device > Battery is a drain meter. PennyOS samples the battery once a minute and reports the last hour as percent per hour, the equivalent current, and the time left. It says "rate in N min" until it has ten minutes of unbroken samples, because a rate from two readings is noise. A shutdown starts the window over, so time spent off is never counted as the device running.
The firmware does not report whether the charger is connected, so "charging" is inferred from a rising trend. A full battery on the charger reads as steady.
Why it barely charges while on
The Beepy's charger is set to 100 mA by a resistor on the board. The device draws about 200 mA when on, so plugged in and running it still slowly loses charge. Charge it switched off.
Replacing that resistor raises the charge current. It is a small surface mount soldering job, described in the Beepy's published schematic, and it is entirely at your own risk: a mistake can damage the board or the battery.
What PennyOS turns off
The stock image powers several things a pocket Beepy never uses. The installer disables them:
- the Bluetooth controller;
- HDMI output, which is dead anyway while the display driver is loaded;
- audio, since there is no speaker;
- the Pi's activity LED, lit inside a closed case;
- ModemManager, with no modem;
- and it sets Wi-Fi power saving on.
Some of these take effect only after the next full power off and boot. The shell also waits longer between passes when nothing on screen is moving; keys and the side button still wake it instantly.
The keyboard light
The Beepy's firmware has no timeout for the keyboard light, so without help it stays on forever. Settings > Display > Light off after turns it off after 10 seconds to 5 minutes without a key, or never, and the next key brings it back. PennyOS also turns it off before a shutdown, since the keyboard controller keeps it powered after the Pi halts.
Shutting down
Use the power switch or Settings > Power off. Holding End Call for five seconds works, but after a long sleep the touchpad can come back unresponsive until the next switch power cycle.