hi we have been off-grid for years and have a Sundanzer frig. https://www.sundanzer.com
this is a chest type and was wonderful till the following problem started late last year when the batteries would not charge so changed charge controller same as we had, a morning star 10A still had the problem then we were away for 10 months, ( all turned off ) when we came back problem is still there. last month bought 2 new 6v 225a batteries connected in series and they aren’t holding up either. we have 2- 75watt panels that have run this in upstate ny for years, till last year any suggestions what happened. but do love the frig and also have a freezer on a totally separate setup in different building.