How often should you start a car in storage?
If a stored car's battery is kept on a conditioner, it doesn't need starting at all for the battery's sake. If you do start it, once a month is enough, provided the engine runs until it is fully up to temperature. The routine to avoid is a quick start every week, with the engine switched off again after a few minutes. That puts moisture into the engine and exhaust without driving it back out, and it takes more charge from the battery than a few minutes of running puts back.
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