I brought it to RenFest last weekend. It poured down rain all weekend, I'm glad I tried to made this thing water-tight. The only issue I had was the waterproof speaker connectors. The plastic I used for the top is actually too thick for the panel mount part, I had tried counter-sinking the hole to make it fit, but one of them fell out of its hole. But because almost everything inside is water-resistant, it continued to work fine, even full of water.

I estimate we used it for about 20 - 30 hours before the batteries got down to about 10v. I planned on taking the top off and letting it dry out, but it was already dry inside the next day after getting back.