I installed two Lifeline GPL-4CT AGM 6V 220 Ah batteries in place of my single Interstate Group 27 flooded battery and it made a world of difference. Yes indeed, the two 6V provide additional boondocking capability. I boondock almost exclusively. I do have 100 watt solar and a Honda 2000.
I had no trouble fitting the Lifelines. The 825 has plenty of space if you’re installing AGMs, which don’t require venting.
I had to do only a minor amount of “surgery” on the wooden platform that supported the single battery.
I took photos of the installation as it progressed, but I’m not clever enough to attach them here.
If you send your contact information to me at firstname.lastname@example.org or call me at 505.301.7461, I can tell you how I did what I did.
As an example of the improvement – I have occasionally forgotten to take my fridge off DC when I stop. When I did that with my Group 27, I ran the battery flat. I did that recently with the Lifelines, for two hours. It didn’t make a dent in the charge state.
If there’s a down side, it’s the cost, $330 each. A lot more than for flooded but a lot less than lithium.
Email or call me.