On Wed, 02 Jan 2019 10:42:27 +0000 (GMT), "Dave Plowman (News)"
wrote:

snip

I have a Halfords charger - a few years old but claims to be automatic. On
the front says 11 amps. It takes longer to charge my car battery than the
14 quid Lidl one which only claims about 4 amps.

But that final time can depend on the time *it* takes to manage the
final phase?

Like the Optimates go though a charge and leave stage at the end and
monitor how much the voltage drops when left. If it drops too much it
starts charging again and will only put up the 'Done' LED, once it
really is. Therefore, it might appear to take longer than a more basic
lower powered charger because it's more thorough?

(I'm not saying that IS the case with your chargers etc ...)

Cheers, T i m