Hi,
I have to replace my aux battery, a NAPA 8G27 (99 AH) gel type. I’m looking for the best autonomy with my fridge to be the main power expense. The venting is no problem. I’m looking at 3 alternatives:
1- get 1 of the same battery type
1- 2 acid type 6V batteries in series
2- 2 acid type 12V in parallel

Is there a better solution out there?

To my understanding the gel type battery will only give me higher life expectancy of the battery with the same autonomy as acid type. Is that a good assumption?
Best regards.
Gilles Turmel