diff --git a/boards/feather-m0/doc.txt b/boards/feather-m0/doc.txt
index b3f0576604c6..4154089e0700 100644
--- a/boards/feather-m0/doc.txt
+++ b/boards/feather-m0/doc.txt
@@ -24,7 +24,20 @@ SAMD21 mcu.
 ### Pinout
 
 <img src="https://cdn-learn.adafruit.com/assets/assets/000/030/921/original/adafruit_products_2772_pinout_v1_0.png"
-     alt="Adafruit Feather M0 proto pinout" style="width:800px;"/>
+     alt="Adafruit Feather M0 proto pinout" style="width:800px;"/><br/>
+
+`AIN7` can be used to [measure the voltage of a connected Lipoly battery][battery].
+It is mapped to ADC_LINE(6) in RIOT.
+
+~~~~~~~~~~~~~~~~ {.c}
+int vbat = adc_sample(ADC_LINE(6), ADC_RES_10BIT);
+vbat *= 2;      /* voltage was divided by 2, so multiply it back */
+vbat *= 33;     /* reference voltage 3.3V * 10 */
+vbat /= 10240;  /* resolution * 10 (because we multiplied 3.3V by 10) */
+printf("Bat: %dV\n", vbat);
+~~~~~~~~~~~~~~~~
+
+[battery]: https://learn.adafruit.com/adafruit-feather-m0-basic-proto/power-management#measuring-battery-4-9
 
 ### Flash the board
 
diff --git a/boards/feather-m0/include/periph_conf.h b/boards/feather-m0/include/periph_conf.h
index 61bdb06118ee..625e94872843 100644
--- a/boards/feather-m0/include/periph_conf.h
+++ b/boards/feather-m0/include/periph_conf.h
@@ -177,9 +177,10 @@ static const adc_conf_chan_t adc_channels[] = {
     { GPIO_PIN(PA, 4), ADC_INPUTCTRL_MUXPOS_PIN4 },     /* A3 */
     { GPIO_PIN(PA, 5), ADC_INPUTCTRL_MUXPOS_PIN5 },     /* A4 */
     { GPIO_PIN(PB, 2), ADC_INPUTCTRL_MUXPOS_PIN10 },    /* A5 */
+    { GPIO_PIN(PA, 7), ADC_INPUTCTRL_MUXPOS_PIN7 },     /* A7 */
 };
 
-#define ADC_0_CHANNELS                     (6U)
+#define ADC_0_CHANNELS                     (7U)
 #define ADC_NUMOF                          ADC_0_CHANNELS
 /** @} */