Another disturbing noise from Ruby

[John Cornforth]

Hi

Worth noting that what is generally sold these days are "Booster Cables". They are OK to rapidly put a bit of charge back into a flat but otherwise good battery, plus supply maybe 50% of the current demand when cranking. The resistance isn't low enough to supply full starter current without significant voltage drop, which is very noticable on a system with only 6V to begin with. Many are aluminium for low weight, which puts up the resistance.

True jump leads are very heavy copper, with a price to match.