[hellosailor]

Compared to wet acid, which is the cheapest battery.

AGM can't spill acid, eat your clothes or anything else. Car upholstery or carpets.
AGM has a much lower self-discharge rate.
AGM can be a 30-50% price premium.
But if you cook an AGM battery, there's no way to "add water" and restore it.

Gel is similar to AGM, offers the most charge cycles, but is most easily ruined by overcharging, and needs different lower charging voltages as well.

 

[hellosailor]

"overkill "
Nah, that's just a rapid charger. You know, like waiting for one clear minute so you can take a sextant sighting on a cloudy day?(G)