Well I got myself the Schumacher Sp3 3 amp charger/maintainer about a week ago. I have to say I was pleased with it in general. Good display that was easy to read, letting you know the percentage the battery was charged etc. I decided after the first battery was charged I unplugged the Sp3 and then plugged it right back in. It did say the battery was at 95% charged. Strange to me in a way... So, I let it charge it back up again a second time. I know the green light is not the end all and be all indicator of whether the battery is truly 100% charged. It is not that at all. I bet if one did this plug in and unplug procedure enough times it would likely be more likely to be truly 100%. I do think it helped my Autocraft Gold battery a bit more than it did with the East Penn Deka battery from the lady's Camry. The funny thing was the East Penn Deka battery showed 12.9 volts right after being charged. The Autocraft Gold showed 12.78 volts afterwards. The East Penn battery showed 95% when I first hooked it up to the Sp3. The Autocraft Gold was at 77% when first hooked up. I know that the after charges were just surface charge values. But it is still a bit interesting that the East Penn was a bit higher. I would also bet the 98 Camry has a "dumb" alternator that actually pushes more amps into that battery. While the alternator in my Altima does not truly push as much amperage into my car's battery. To save gas I bet... Thus the difference of open voltage readings between the two batteries before charging.
Overall, I am very pleased with the Schumacher Sp3 charger/maintainer. I would give it 4.5 stars out of 5.
Nissan Altima 3.5 Coupe
Federated Auto Full Synthetic 5w30 Hastings LF 240
"Treat your family like your friends and treat your friends like your family."