Take batteries out of the lights before storing!
These batteries worked great for our wedding and lasted all through the night. Then we stored the lights for future use with these batteries still in them. Took them out a month later and the lights were still looking good and in working order. After approximately 9 months, went to take them back out and there was a brown rust-looking goo (battery acid?) coming out of some of the lights. First, we thought maybe the lights got wet or moist somehow and were rusting over even though they were stored neatly in a box and in a dry place. Then we started opening each light and noticed the brown goo was coming from under the battery plastic and not any other metal parts of the lights. 12 out of my 50 lights were salvageable as long as the goo did not leak out from under the plastic and did not touch any metal parts of the lights. However, most of my lights were not salvageable since the goo was all over the metal battery connections. The lights would not work even after putting new batteries in. I've kept name-brand batteries stored in other appliances much longer than 9 months and the worst I've seen is a tiny bit of blue colored battery corrosion but that little bit didn't break the appliance. We got the 12-LED hanging remote control lights @ $5.50/ea. It's a pain to screw and unscrew the batteries in and out every time you'd want to use them. I think it would be worth spending the extra money on better batteries that you could just keep in the light.
ConsLeaks brown goo in less than 9 months and will break your lights.