Do you have a way of cycling your batteries? I would charge them up and cycle them down then charge them up and then check them to see where they stand. I think they should be a some think like 75% to still be good. Anything lower than that and you'll want to cycle them a couple more times to see if you can bring them up (if they're anything less than 90% I would anyway), if they don't come up toss em. The price of a new pack is worth your plane easily. Also next winter when you store them away again, keep the batteries and what ever you may use to cycle them handy and do it once month or every two months. Keeps the batteries up to snuff and makes sure they are good for spring.


As for the fuel. I personally think it depends on where you stored it and how much of it you used. I generally toss any gallons that are more than half empty, and over a couple two/three months old. I have used them but I don't seem to get very good engine runs out of them.


As for the rest I usually just go over all the nuts and bolts and check to make sure everything is tight and adjusted right. I usually get bored way before spring and tear all my stuff apart and fix everything that was bothering me last summer. So by the time spring gets here I have gone over everything twice. After all winter off that first spring flight is almost like flying for the first time. Nothing like flying with tattatat of your knees knocking!