The Freas is not unbreakable but the column is made from Pyrex. I detailed a way to construct a PVC tube to protect the unit while in storage.
A quality AGM battery may be a significant step-up if performance is what you seek. Their penalty as compared to lithium is weight. Lifeline says their product will endure 500 full discharges to 0% SOC. But under load their voltage remains very high. But a strong solar panel would help in the partial recharge quandary. AGM is less sensitive to partial recharge than are flooded batteries. But a person needs good instrumentation to condition them.
I get weak-kneed when I price lithium.