Tom Del Rosso wrote:
If you turn over an engine periodically to keep it charged, how long do
you run it to make up for the charge lost in starting?

In this case it's my neighbor's 87 Buick Regal while he's in the
hospital.

5 min once every two weeks should be sufficient assuming the
battery and charging system is good. Turn everything off except
engine. It will need to be run at least 1,000 rpm for that time
period.

OTH, Harbor Freight has cheap little float chargers but 120v power
will be needed. A friend uses one of these when out of the country:
https://www.harborfreight.com/automa...ger-42292.html