By dead you must mean partially discharged vs dead where the engine wouldn't run. 10 miles is rather short so the batteries must have been discharged before you left and unlikely to have significant charge but some upon return if everything is working.
First fully charge the batteries now as otherwise their life is shortened. Next load check the batteries to be sure they are OK. Next use a voltmeter to determine that the alternator is OK and charging the batteries.
Consider disconnecting the batteries when stored to prevent significant discharge for a number of months with good batteries.