I had 2 Optima failures, one 4 or 5 years ago and one last weekend on a 1150 mile trip. The first one went dead with no signs of being weak, just rolled over and died. The second started about 300 miles into the trip. The engine always starts on the first turn, after lunch it turned three times very slow and I pushed the button again and the solenoid went click, click. I jumped it with the 12 volt battery pack, POS to ground and neg to the starter side of the solenoid. This pack has a switch to energize the cables. I got my wife to turn on the ignition and with the battery pack laying on pillow on the fender I got a hold of the carb linkage and turned the battery pack switch, it turned over, started and I shut the battery pack off. When I needed to get gas I parked at the end pump with the front of the car heading down hill and jumped started it most times, a few times I had to use the battery pack. Continued to Savannah,Ga. running for over two hours with the head lights on and the 6 volt alternator I made showing 7.5 volts in the day light and 7.4 with the lights on. Traveled 625 miles on Saturday. Sunday morning had to use the battery pack, couldn't get enough roll to kick over. Had 525 miles left and the battery was getting worse, I flicked the head light switch twice to let a trucker in and the engine shut off fast twice, the digital volt meter went black and the GPS cut off. So after that I used the hand for turn signals, the GPS worked and the engine never missed a beat the whole trip other then when the load was to great. The alternator charges at idle where the cut out on a generator cuts the generator off at low RPMs so I would never had made it with a generator. I removed the battery and it wouldn't take a charge and turned the charger to 12 volts and the area around the POS terminal got hot. I cut the top off the battery and the POS connection of the lead plates from the cell to the battery terminal arced off but made a weak connection across the arced parts. I measured the voltage from the NEG terminal to the arced ends of the POS plates down in the cell and got over 7 volts, hooked up a sealed beam head light and it lit up bright. I also had the battery that failed years ago but never got around to cutting it apart so we opened it up and the failure was exactly like the second one except as you can see in picture 0097 of the older battery after sittng for years every thing above the cells was corrioded. There was light corrosion on the newer one. There is a vent over near the POS terminal where both battery connections arced off. I haven't checked if it's just a vent or a valve but I think it's only a vent and the air with the acid corriods the lead. These are realy lead acid batteries. The cells look like a roll of paper towels with lead strips rapped in a fabric and soaked in acid. I don't know if the vent is to release pressure but if thats the case a light check valve would do that and keep the air out. The lead parts should be coated above the cells to keep the lead from erroiding. 0104 shows the external POS terminal held firmly in position so it wasn't twisted internaly. 0102 shows where the 7 or 8 plates attached to the POS terminal post arced off, not at the connection but in the area afected buy fumes. I'm not bad mouthing the Optima I still like them and if they last 4 years without acid damage I'm satisfied but I think there is room for improvment. I see the numbers didn't post with the pictures but you can figure them out. G.M.