Your last question is very valid and yes that is very probable. If it's been a year or two on that battery ,then it's probably time. To be sure , get a small volt meter and see how many volts the battery has after charge. You can get a little more life out of it if you drain the battery alllll the way down. It might last a time or two or so but good luck . Oh motors are generally fused so it is possible you could have just blown one. Just trace wire down to find , Good Luck.