>>1211746> Flooded batteries are a lot cheaper than those. The general rule-of-thumb is that a conventional car starter battery shouldn't be discharged more than 10%, a “deep cycle” battery no more than 25% while an AGM battery can be repeatedly discharged 50%+ and recharged far more times.
There is really no reason not to use an AGM battery nowadays, especially as the prices are comparable, they’ll last far longer, provide more energy and don’t release hydrogen gas (which is obviously dangerous in an enclosed space).
Pretty much all the commercial power packs on the market use AGM batteries but for what you’ll pay, you’re better off building your own power pack that’ll not only be cheaper but usually more powerful (commercial power packs tend to use a single battery no larger then 55ah).