I just got confirmation that my chargers have been shipped. I went with four
Soneil 1206S chargers. They are 3A onboard automatic smart chargers. This should allow me to use the mower, plug in, and forget about it until I need to use it again. They'll also allow overnight charging, so I can use it every day if I wanted.
I will wire all the chargers together so its just a one plug deal. This setup will be much better than my current method of charging each battery individually with one charger and having to remember to move the charger to the next battery 1-2x a day.
They did cost a pretty penny at just under $50 each, but it will make the mower a lot easier to use. I'd like to get it to the point where its simpler to use than a gas mower, and I think I'll be very close once I get the chargers installed.
On another note, my wife cut the grass for the first time with the mower this week. It took a little instruction, but she had no problems with it other than the normal quirks of having a 30 year old mower.