A G M battery?

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Originally Posted by JFP in PA

AGM or absorbed glass mat design batteries have been around for a long time. Probably the best known brand is Optima. While much more durable, longer lived, and vibration resistant than a conventional design battery, they will still go dead in a stored Porsche without a proper maintainer attached due to the car's inherent parasitic current draw............

+1
If you disconnect the battery completely an AGM will hold a charge better than a lead-acid battery. If you leave it connected for months, it will still be dead and battery damage will be done.
Optima AGM are about 10 lbs lighter than stock
Odyssey PC 680 AGM is about 30 lbs lighter than stock.
Shorai is Li-Iron Battery, 5lbs total

More info:
ODYSSEY Batteries - FAQ