Battery Bosch or OEM Volvo

The battery in my MB was the original Bosch so 20 years old when I replaced it.

(for general reference Lion are one of the worst battery brands out there. Exide are OK but that's far too expensive. Bosch and Varta are generally the exact same product with different stickers on and are always good, and rarely all that expensive.

I will second a class 3 Bosch. I have one in a hilly city that absolutely rocks the steeps and has a great battery life. Going on 2 years strong and I've had zero battery issues. It rains a lot here but no problems with the Shimano drivetrain either, just regular maintenance.

I have a Cube Stereo Hybrid pro (insert numbers here)

Priced about 3.5k retail, it's an absolute dream to ride. Quiet, huge battery (bosch power tube 800)

I had to change the battery on my Volvo 940 7 years ago, it was the original battery from 1996 Wich means that my battery lasted for 22 Swedish winters.

The Bosch has slightly lower Cold Cranking Amps at 330 vs the Yuasa at 360. Also Bosch has 4 yr warranty vs Yuasa 5yr.

my dishwasher has around 200 mile motorway range on a 64kWh net battery, which'll get me from Oxford to Darlington on a single charge, I could get to Newcastle if I camp behind a truck for most of it. My car is also stupidly inefficient for an EV, better EVs like a ID.3 or Megane could go further with smaller batteries.

The battery is almost certainly dead.

Something else wrong with your car likely killed the battery and if that's the case buying a new battery will just result in the same problem pretty soon.

That battery is absolutely cooked, sounds like the cells have sulfated to hell or there's internal damage from deep cycling

The fact that it's only taking 72-94Wh when it should be 600Wh is screaming dead cells, and that voltage drop from 12.8 to 4v in 2 hours is not normal even with parasitic draw

The battery is trash - if it was at 4v, the cells are either internally buckled/shorted - or the AGM is damaged and thus will not hold any charge (no capacity).