Is your battery fully charged? If you have one of those L-Ion booster pack thingies it might be worth trying it as an assister if by 'reluctant to turn over' you mean the engine isn't cranking at its normal speed.

Many modern car systems are quite sensitive to battery voltage and if your battery is maybe a bit tired and not delivering the full 13V or whatever it might throw a MIL.

Tim H.
1986 4/4 VVTi Sport, 2002 LR Defender, 2022 Mini Cooper SE