Personally I bought a sealy capacitor based jump pack, it charges the capacitors up from even a dead battery and jumps starts the car really good. They do 12 and 24 volt ones. Never needs charging just stick it on goosed battery press the button to energised the capacitors and then crack on.
Not cheap but very good piece of kit
I’ve got the E start 600 or 800 and it starts my 2.0 diesel no bother and has started many cars no issues.
But if the battery is beyond dead sometimes it won’t start them as it doesn’t have enough oomph. But for general low battery they are a great piece of kit.