An external lithium battery (like Panasonic [https://industrial.panasonic.com/ww/products/batteries/secondary-batteries/coin_rechargeable_lithium/models/ML2020 ML-2020/G1AN] rechargeable battery) can be optionally mounted on SBCX.
[[File:AXEL Lite-EVB-Battery-connector.png|thumb|center| 500px|Lithium battery]]
===Signals ===