I have two Optimate chargers, a Honda 3+ and a Optimate 4, and finding the online manuals is a bit of an issue. This is because fo the poor rebadging and renaming system. Optimate was sometime Accumate, and the Honda 3+ isn’t necessarily the same as the Optimate 3+ (although I am not sure what the exact differences are). Ridiculous, I know. Anyway, here is a collection of the links that I have found.