On Mon, 10 May 2021 00:35:35 +0100, "Dave Plowman (News)"
wrote:

snip

Try leaving one for six months. Also, I bet most of these contain
bargain basement batteries.

Are you saying a Li-Ion one - which starts off with less capacity

Whilst it may start off with less Ah capacity, it may well have a
greater cold cranking current so more likely to start a car, assuming
it's willing to start easily.

- is
going to be fine after 6 months, like for like?

Yes.

I'd say most Li-Ion jump
start packs ain't got the finest either, by the price.

But I'm not sure they need to, given what sort of CCA even low spec
ones can output.

If you want a bit of a rambling redneck overview of a LA V Li pack
(all be they way different prices):

https://www.youtube.com/watch?v=PwA78cGULDY

Cheers, T i m