Yesterday I put the final piece in place to our solar powered lawn-mowing solution. At the old house, I used the reel-mower - not a terribly onerous task provided it was kept sharp. But at the new house we are on a corner lot, and inheriting our predecessor's love of lawn. We are slowly eating away at it with vegetable and xeric beds... but a lot remains. Too much to feasibly manage with the reel mower - especially if I want to share the task with other members of the family.
So, we bought us a Neuton Electric Mower which has the useful distinction of being powered by a removable 24volt sealed lead-acid rechargable battery. We also bought an extra battery. While they dont supply a solar recharger (it comes with a big-brick mains recharger), eBay (for example) does - I was able to buy a simple 24v recharger package with a solar panel, recharging circuit and leads.
I hooked it all together at the weekend, quickly corrected the polarity (+1 for testing) and plugged it in. Yay, the little charging light on the batter lit up. I secured the PV panel (little one about 6" square) to a bit of wood, and repositioned it a couple times over the course of the day.
I have fingers crossed. My tests showed I was getting close to the same output (in volts) from the PV panel, in almost full sun. But, not quite. I know just a little about battery charging, but enough to be aware that it needs to exceed the rated voltage of the battery to work.
Its raining today, so the results are not yet in. But worst case is that I have to tweak the battery-charging circuit piece of this solution (the component - I'm not proposing to tweak the circuit itself, not yet). Neuton said they have had other customers do the solar recharging thing too. Maybe they or a 3rd party could be persuaded to produce an off-the-shelf solution to put solar-powered moving easily into the hands of the masses. We need one badly here in the south - where sun and lawns are both in abundance.
The mower itself: works pretty well. As you'd expect, its quiet (another plus, you can carry on a conversation while mowing). A full charge gets me around our lawn about twice (very approximately 3500 sq ft). Its powered appropriately, my only reservation is the width of the cut - about 15" - so the whole task takes a little longer that your average gas-hog mower might. But it doesn't leave your nerves on edge, can be carried out in the cool early mornings without waking neighbors, and shared across the whole family. I think its a winner.
Update: With great hindsight, the solar panel size was obviously the problem - it was way too small to be useful and charging would take weeks, if at all.