I was looking today for more information as to how low Receiver Batteries should be allowed to go before pulling the boat out for a fresh battery. The numbers above are per cell, so as most of our batteries are 2 cell, just double the above numbers.

This was a super explanation and you can read it in full here

https://nexusbatterysystems.com/blogs/battery-knowledge-base/battery-voltage-explained-nominal-charged-minimum-and-cut-off-levels