not sure how to check the voltage. I basically don't know much more than how to charge it. I did call the place I got it after posting earlier this evening and he was still in his shop. He suggested trying to charge it the correct way. I did, and oddly it showed as fully charged with green lite after only about 20 minutes. I hooked my old troller up to it and tried it out. It ran, but it doesn't seem like it should be that easy. The battery is enclosed so I cant see the level inside. Unfortunately, I don't even know what electrolyte is; I'm guessing that's the acid? Im brand new to boating, but learning something new everyday (thanks to tinboats). I have the number to Interstate tech support and I'll call in the morning. I'll take the battery where i got it and let them put it on a meter. I was planning in fishing tomorrow, so I hope I'll be in good shape. If not, I'll have to buy a new one and never make that mistake again. My modification is almost complete and I hope to post it soon. Thanks for the quick response.