On 9 Feb 2018 11:08:23 GMT, Huge wrote:

snip

Indeed. Car batteries are certainly not 'snowflakes' (if I may be
excused for using a presently-fashionable word), and are designed to
have a hard life.

Although running them flat is guaranteed to kill them, since they are
not designed to survive this.

Correct. Even discharging a deep discharge LA battery to 50% capacity
or more will effect it's cycle life.

That's why "leisure" batteries exist.

They are no more able to survive being run flat (especially for a
prolonged period) than any other LA battery.

The main difference between an SLI and leisure / traction battery is
the thickness of the plates and hence the capacity / kg.

Cheers, T i m