After insulating my battery and sticking a small heating mat under it, it was time to test it.

Happy to report that thing is pretty nice. With -9°C outdoor and a battery at -6°C, the mat progressively warmed it up to 2°C under 1 hour and would have continued if I did not stop it.

Without much else going on (in a 24v system), it drew ~ 80 watts before 0°C and then moved to ~ 56 watts.

The temp sensor is on top of the battery (on the positive terminal) while the mat is underneath the battery so it should be healthy measures.

Time to get smart with the relay and I should be able to harness more solar power! Today is a lost cause because the panels are covered by a sheet of snowy ice 😅.