For the exhaustive details, you should look up the fine folks at candlepowerforums.com -- but search existing threads first because they get a little testy when the same question is asked over, and over, and over again. For purists, there's a surprisingly complex charging profile, over time, for these cells.

My (very primitive) understanding is that both too high and too low a charge rate have negative impacts on the performance and longevity of a cell. This is all based on a percentage of the individual cell's capacity. The c9000 (I have one too) won't take you astray since it's a smart charger, but I lean toward 500mA vs. the default 1000.

But I must confess that I mostly use the maha as a diagnostic or forming charger (and high-powered night light). My go-to charger for cells in constant use is the under-appreciated Duracell CEF23 with the 12VDC plug. IMO it's a pretty sweet companion (I have three actually) with my solar setup.