i've been working on Li Batteries for a few weeks since we're going to upgrade in spring 21.
for our SM, I have a narrow selection
the batteries from
Victron ,

https://www.victronenergy.de/batteries/lithium-battery-12-8v

liontron

https://greenakku.de/batteries/lithium batteries::7_56.html? gclid=EAIaIQobChMIjf61rvaZ6wIVjqmyCh33DAtUEAAYASAEgJzovD_BwE

or from a company Ripower in Germany that can build batteries on your desired dimensions! Price not much difference from standard batteries .

https://ripower.en/

Greetings to Elja
SM Balu 222

Von meinem iPhone gesendet