My dad's had one of these portable rechargeable jump start battery units for the last 10 years or so and it finally died recently when he tried to use it to jump start his car after he'd left the car lights on overnight, so it's time for a replacement ahead of winter. Any suggestions welcome particularly those based on personal experience.
To be used to jump start an 'up to 2 litre' petrol engine and no more than £50. Occasional 'light emergency use' so does not have to be super heavy duty. The one he had was an unknown far east branded bulky unit containing lead acid batteries. I understand there may be new technology for this type of thing now.
Open it up & replace the battery, just get the best battery your budget allows.
NB, I use a Snap-on one professionally as the cheap ones are crap & we never got more than a few months out of even supposed pro ones we tried, the battery on the Snap-on alone is £100 which gets replaced every year or two.
HTH.
Just use a well charged car battery. And jump leafs?
Not sure how good these things are...
The good quality LiPo boosters are actually pretty good.
I've seen one manage to crank a totally flat transit for a couple of turns, before the booster went too flat to do crank it anymore.
Not sure how they'll hold up longevity wise though, as LiPo's don't really like being kept fully charged.