Tecmate Optimate 3 Plus Battery Charger - --

• Vent free enclosure
• SAE connectors
• Moulded wall mounts
• The OptiMates high voltage desulfation mode cannot engage if vehicle electronics wiring are sensed, so to effectively desulfate a battery, it must be disconnected from the vehicle wiring
• Recommended for all 12V lead-acid batteries from 2Ah to 45Ah, although it can also maintain larger batteries it will just take longer to charge

First off, I didn't purchase this item on Amazon, it was a gift from a Canadian friend, so there may be some differences between my product and the one sold here. Mine is an Optimate 3+, and looks the same as the one pictured, except that its a different color. That out of the way, I can say that I bought it after the battery in my 2006 Porsche 911 Carrera S lost 100% of its charge and was deemed to be dead. My Porsche dealer replaced it, not with a Porsche battery, but with an Interstate MTP-91. So I'm now being quite careful with my battery.

It is early days, but the Optimate 3+ has bee working well. It has many modes, which correspond to the different battery states that it identifies. I'm no battery expert, but it seems to have a mode for nearly every condition. It has a maintenance mode, so I can leave it plugged in permanently, aparently. I will update this review in the future as I get more experience with it. So far, it is doing what I want: charging when necessary, and keeping the battery fully charged without overcharging.