Just for info Tayna deliver filled lead/acid batteries.
They plug the vent and use a sealed plastic bags etc.
Tayna provide straightforward excellent service and provide both brand names and cheaper alternatives. A Yuasa from Tayna won’t be a fake which is always a possibility from some eBay sellers.
For what it’s worth I’ve a Yuasa 6N12A-2D (6V 12Ah) battery fitted to my 6V TS250/1. This battery is a different size to the standard battery and is a nice fit in the battery compartment across the frame rather than in line. So far, about two years, I’m happy and fully expect it to go on for a few more years. Every time I’ve bought a cheap no name battery from eBay it’s not lasted and been a waste of money.
All battery technologies require a specific charging protocol to maintain them in good health with a long life. Unfortunately the charging systems of most vehicles is a basic “apply maximun voltage at all times”. This is not a correct charging protocol for any type of battery and the type of battery which copes best with this is Lead/Acid, because it is basic and robust.
I know Bynnzi has not has luck with Motobat AGM batteries on several of his bikes.