Battery stuff

Getting-started.md

@@ -62,7 +62,7 @@ The two main menus to know are:
 * `BatSav` for the active/sleep ratio during normal operation
 * `SetOff` for deep sleep after a period of inactivity
 
-See [Radio operation](./Radio-operation) for the detailed behavior of sleep mode.
+See [Radio operation](./Radio-operation#battery-display-type-and-calibration) for battery display, battery type, and calibration, and [Radio operation](./Radio-operation#about-the-setoff-menu) for the detailed behavior of sleep mode.
 
 ## Model differences
 

Menu.md

@@ -67,7 +67,7 @@ The number in front of each menu item description is the **_menu item number_**
 1. `KeyLck` - auto keypad lock option (OFF or 15 seconds to 10 minutes before automatic keypad locking)
 1. `TxTOut` - max transmission time limit
 1. `BatSav` - battery save option, a rate between active time and sleep time (OFF, 1:1 to 1:5)
-1. `BatTxt` - additional battery value on the status bar in % or volts
+1. `BatTxt` - additional battery value on the status bar (`NONE`, `VOLTAGE`, or `PERCENT`)
 1. `Mic` - microphone sensitivity
 1. `MicBar` - microphone bar that appears while transmitting 
 1. `ChDisp` - channel display style
@@ -88,7 +88,7 @@ The number in front of each menu item description is the **_menu item number_**
 1. `D Prel` - DTMF pre-load time
 1. `D Live` - displays DTMF codes received by radio in the middle of the screen
 1. `VOX` - voice-activated TX sensitivity level
-1. `SysInf` - battery voltage and percentage
+1. `SysInf` - battery voltage, battery percentage, and firmware version
 1. `RxMode` - sets how the upper and lower frequency is used
    * MAIN ONLY - always transmits and listens on the main frequency (`MO`)
    * DUAL RX RESPOND - listens to both frequencies, if signal is received on the secondary frequency it locks to it for a couple of seconds so you can respond to the call (`DWR`)
@@ -165,8 +165,8 @@ The hidden menu is activated by holding `PTT` + `SIDE BUTTON 1️⃣` while turn
     * DISABLE ALL - disables TX on all frequencies
     * UNLOCK ALL - enables TX on all bands. It has an additional lock; see [how to turn that on](./Advanced-features#tx-on-all-bands).
 1. `350 En` - enables RX on `350 MHz`
-1. `BatCal` - battery calibration, measure the voltage on the back of the radio, and adjust the value in the menu accordingly
-1. `BatTyp` - battery type. `1600 mAh`, `2200 mAh`, and `3500 mAh` batteries have very different discharge curves; this setting is used to calculate battery level percentage
+1. `BatCal` - battery voltage calibration. Compare the displayed voltage with a multimeter and adjust it until they match as closely as possible
+1. `BatTyp` - battery type / discharge curve used for the battery percentage calculation. It affects `%`, not the measured voltage itself
 1. `SetNav` - configures the navigation type (UP/DOWN for UV-K5, LEFT/RIGHT for UV-K1)
 1. `Reset` - resets radio configuration settings
    * VFO - removes only channel settings

Radio-operation.md

@@ -14,6 +14,7 @@ For scan-related features, see [Scanning](./Scanning). For Air Copy, RescueOps,
 
 * [Basic operation & configuration](#basic-operation--configuration)
 * [Status bar](#status-bar)
+* [Battery display, type, and calibration](#battery-display-type-and-calibration)
 * [About the `F Lock` and `TXLock` menus](#about-the-f-lock-and-txlock-menus)
 * [About the SetOff menu](#about-the-setoff-menu)
 * [1750 Hz tone burst for repeater access](#1750-hz-tone-burst-for-repeater-access)
@@ -59,6 +60,51 @@ At the top of the screen, on the first line, is the status bar. It displays a lo
 > [!NOTE]
 > About `RxMode`, `MO` means MAIN ONLY, `DW` means MAIN TX / DUAL RX, `DWR` means DUAL RX RESPOND, and `XB` means CROSS BAND.
 
+## Battery display, type, and calibration
+
+The firmware separates three different battery-related things:
+
+* the measured battery voltage
+* the estimated battery percentage
+* the sleep / power-saving behavior
+
+For battery information on screen:
+
+* `BatTxt` adds `VOLTAGE` or `PERCENT` to the status bar, or hides it with `NONE`
+* `SysInf` shows the corrected battery voltage, the estimated battery percentage, and the firmware version
+
+For battery percentage to make sense, two hidden-menu items matter:
+
+* `BatCal` calibrates the displayed battery voltage
+* `BatTyp` selects the discharge curve used for battery percentage estimation
+
+Important difference:
+
+* `BatCal` changes the voltage reading
+* `BatTyp` changes the `%` calculation, not the measured voltage itself
+
+Current `BatTyp` choices are:
+
+* `1600mAh K5`
+* `2200mAh K5`
+* `3500mAh K5`
+* `1400mAh K1`
+* `2500mAh K1`
+
+As with any voltage-based estimate, the battery percentage is only approximate. It depends on the selected battery profile, the battery condition, and the current load.
+
+### Calibrate the battery voltage with a multimeter
+
+1. Make sure the radio is not charging through `USB-C`.
+1. Let the radio stay idle for a moment. Do not calibrate while transmitting.
+1. Measure the battery voltage with a multimeter on the battery contacts at the back of the radio / battery pack.
+1. Open the hidden menu and go to `BatCal`.
+1. Adjust `BatCal` until the voltage shown by the radio matches the multimeter as closely as possible.
+1. Confirm with `M`.
+
+> [!TIP]
+> If the voltage is correct but the percentage still feels wrong, `BatCal` is probably fine and `BatTyp` is the setting to review.
+
 ## About the `F Lock` and `TXLock` menus
 
 In the past, there were a few band plans in the `F Lock` menu to meet various requests: PMR 446, FRS/GMRS/MURS, etc. However, adding new `F Lock` options always took up a lot of memory: new options in the `F Lock` menu, storing frequencies (for specialists, these are `uint32_t` each time, so they are very memory-consuming), etc.

Troubleshooting.md

@@ -91,6 +91,23 @@ If one AM reception sounds too harsh in `SHARP`, try `STOCK` or `OPEN`. If it so
 
 See also: [Menu](./Menu#main-menu) and [Button functions](./Button-functions#custom-button-functions).
 
+## Battery percentage or voltage looks wrong
+
+Check these points:
+
+1. make sure the radio is not charging through `USB-C` while you check it
+1. use `BatTxt = VOLTAGE` or open `SysInf`
+1. make sure `BatTyp` matches the battery pack you are using
+1. compare the displayed voltage with a multimeter
+1. if needed, readjust `BatCal`
+
+Important reminder:
+
+* `BatCal` affects the voltage reading
+* `BatTyp` affects the battery percentage estimate
+
+See also: [Radio operation](./Radio-operation#battery-display-type-and-calibration) and [Menu](./Menu#hidden-menu).
+
 ## The external microphone PTT behaves differently
 
 This is a known behavior on some hardware revisions.