Update README.md

README.md

@@ -231,7 +231,7 @@ The battery voltage is used for:
 * Battery deep-discharge protection and energy saving mode
 * Monitoring battery status via uplink (e.g. for optimization of transmission interval)
 
-> [!NOTE]
+> [!CAUTION]
 > **The following section is meant as a general introduction. Actual implementations may vary. Consult you board's documentation for details!**<br>
 > The boards used in this project can be supplied by 5V via USB or by another supply voltage via a second power supply connector. Many have an integrated lithium-ion battery charger. A lithium-ion battery has a voltage range of ~2.4...4.2V. The usable voltage range for the board depends on the actual circuit. If a voltage regulator is used (and no voltage converter), the usable battery voltage range is ~3.3...4.2V.