A weak battery could indeed be hindering your progress - can you jump start or borrow another battery? Your battery should physically fill the battery tray - sometimes people fit smaller ones 'cos they are cheaper but they aren't always up to the job when they get a bit older.

As I'm paranoid I'd also check to see if I can turn the engine by hand - crankshaft nut 27mm

Good luck.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!