On Wednesday, February 6, 2019 at 11:09:24 AM UTC-5, wrote:


If it's below freezing the air is bone dry & any water from combustion frozen solid. Regardless of temperature cars do not need running every 2 weeks unless electrically faulty.


Water in the air is not the issue, and never was. Water from products-of-combustion are the issue.

Ideally, the battery would be float-charged with an actual "smart" charger. Most of the Chinese Junque chargers these days run a continuous charge into the battery - AKA a "trickle" charger. Not hardly the same thing. A trickle charge will either:

a) Destroy the battery by charging faster than the self-discharge rate.
b) Allow the battery to run flat by charging slower than the self-discharge rate.
c) Miraculously match the self-discharge rate... odds of this?

A Float Charger will activate at some point when the battery charge drops below the trigger level, charge to a specific set-point, and then shut off until the next cycle.

Failing the availability of a float charger, and, especially in extreme (hot or cold) weather conditions, "about every two weeks" is a good rule-of-thumb. One never quite knows the actual condition of the battery, charging system, parasitic loads and so forth, so 'designing to the specific need' may not be ideal. And more than a month or so starts getting into the risk of seals drying out - especially in 30+ year old engines.

Peter Wieck
Melrose Park, PA