You cannot charge an Optima like a normal battery. Battery tenders will NOT charge them. I found the best way to charge one it to put it in series with a regular battery on a 30 amp charge for a few hours, then switch it to 10 amp. There are specific types of chargers for Optima type batteries, but if you don't have one my method is preferred... Edit: I just read your post again, sounds like you tried it through another battery already, may have to charge it longer. One of mine sat for 3 years and I brought it back to life that way.