Let's see, five deep discharge cycles
Battery goes bad
200 miles to nearest Wal-Mart (maybe a lot more than that)
Gasoline is free! oh what the heck go for the starter battery. Four or five otter get you through this... Wal-Mart is not going to warrant them until they utterly fail. Enjoy your ten minutes of light per night.
Back in the 70's I used to DAMAGE group 27 starter batteries with 2 70% discharge cycles. My VAT 40 confirmed the CCA would drop from 480 CCA to 400 or a bit less. Could not be recovered. Interstate batteries. So the advice about using thick plates batteries isn't a bunch of hyperbole.