My suggestion is investing in the following charger is you haven't already found one. It was recommended to me by quite a few people and I have grown to love it. I'm sure there are many user's that can attest to it's greatness lol. Universal NPT Smart Charger
http://www.airsoftparts.ca/store2/in...oducts_id=1030
Airsoftparts.ca has lots in stock and for a good price. And on Styrak's note it includes Delta V detection. I know it wasn't really on the topic of whether you can tell but I hope it helps out
Edit: I noticed you're in the States, my suggestion still stands buuuuuuuuuut.. May want to rethink that lol XD
Best of luck!