S1 Pro Battery Sleep Mode
Here is an excerpt from the S1 Pro Battery Owners Guide
Sleep mode is to protect the battery.
Sleep mode is the lowest current draw of the integrated circuits (ICs) in the battery pack. If the ICs were left unchecked, eventually they would drain the cells below their safety threshold. When the cells are allowed to discharge below a certain level, they become susceptible to dendritic growths within the cells. This can lead to catastrophic failures of the cells. The battery fails and is non-recoverable.
We use the sleep mode (or shipping mode) to extend the timeline long enough to greatly reduce the occurrence of failed battery packs.
If you have lithium-ion battery powered tools, you have probably experienced this. You put the tool away at the end of the season. Next year, you take them out again to use them only to find the battery no longer works and you have to replace it (you prevent this by storing them in the charger instead of leaving it in the tool). The use-profile for the S1 Pro System is that it will be used in the warmer months, and with a very high likelihood, it will be put away in the colder months. This is why we put it back into sleep mode when not in use for more than 30 days.