whiskeywalrus
Batteries wear out the least if they have a 30% gap between the lower and upper range, i.e. never have less than 30% remaining charge and never have more than 70% charge.
It then also takes a little longer to achieve the corresponding number of full charge cycles.
A good compromise for frequent users or users of devices with very small batteries is charging at 20 to 80 %.
This wears out the battery more quickly, but the device can be used with fewer restrictions or the owner may not feel so restricted.
Conclusion: If it is possible for you or if you do not find it strenuous, charge the battery at 30 or 40 % and only charge it to around 70% if you are not using the device locally for hours on end.
It would be ideal if we could set not only 80% but also 70% as the charging limit in GrapheneOS.
If I understood the release notes correctly, the GOS developers may realise this later.