Uricanejack
Well-Known Member
I carry a car jump starter pack for this very scenario.
I have one of those. For the car, It was a mid range version. When needed it never worked. tried it on the boat. Not a chance.
We have good 24 volt version. Works well but you have to keep them on charge most of the time. When not in use.
Trouble with the car boot version. They loose their charge when left in the boot.
Now I just carry cables.
A spare 12 volt battery seems like a good idea. If you charge it regularly.