Might be able to arrange borrowing a company vehicle and leave the battery on charge here overnight. would still have to drive it home in the dark tomorrow night though. I should have two charged up batteries by then, so much better chance of success.
Might give the guvnor a call and see if I can do that.
Ideally you need a bit longer than that, fully charge the battery over a 24 hour period, slow charging if preferred if time permits, when fully charged leave the battery somewhere cold for another 24 hours to rest back into its natural state.
After this process and before reconnecting back in the Car a quick voltage check will give a good clue as to the condition of the battery, 12.5 to 12.6 should tell you the battery is good to go, reconnect back in the car start and remeasure the volts, on a fresh fully charged battery I would expect to see 14V+ straight away from the Alternator at 2k even fully loaded with lights on, rear screen etc.
Assuming its not a Maintenance Free Battery, check and rectify any low Battery Acid level and rectify before Charging.