Daytona 650 Battery

You will pay a premium without a trade card.....

https://www.tayna.co.uk/motorcycle-batteries/f/triumph/daytona-600-650-speed-four-03-05/

Here’s a selection. It’s an AGM (glass mat) you probably want and the Cold Cranking Amp rating is your best guide to starting power. However that is usually achieved by more thinner plates so can come at the cost of battery life unless you keep it on a tender.