Originally Posted By: K447
A modern alternative is to carry a compact high output lithium 'jumper pack'. The better quality packs are not only quite compact but also pack enough output to actually start the engine in cold weather. And do this multiple times. Charge it periodically to ensure it is fully capable when it is needed.

Aiming to buy one of these in the future, the lithium battery capacity seems rather nice. Though not sure about carrying one. wink