As long as you match (roughly) the voltage of the existing system, you do NOT need to replace any of the electronics, and probably should not! The controller and other electronics on a scooter are much simpler than they are on a power chair, but replacing / upgrading them is still going to be a complex task that adds much work for relatively little benefit...
Almost any good lithium conversion will need a 'smart charger' that can balance the individual cells, we STRONGLY recommend the Revolectrix / CellPro PL-8 as the best that is currently on the market for various technical reasons discussed elsewhere. One downside of the PL-8 that is shared by almost all smart chargers is that it requires a separate power supply, ideally around 24-30V, 50A output to drive it.
There are several options for the actual battery cells to make up a pack. It used to be that the Headway cells were the only reasonably good choice, but there are now many other options, which one is best will in large part depend on the exact size of your available battery space. Another major decision is whether to replace the existing lead bricks with a lithium pack or to keep them and do an add-on pack. Some suggest doing the add-on first as a learning experience, but I'm not convinced that it is all that much simpler than a full replacement (although it is less money since you will probably be making a smaller pack) I would possibly consider what sort of shape your current batteries are in. If they are relatively new and in good shape, an add-on will let you get a lot more life out of them. If they are older and close to needing replacement anyway, then a full pack replacement might be a better choice...
ex-Gooserider
aksel wrote:I got caught up in some other things but recently took a trip to Washington DC to do some touring. We estimated that the first day was about 10 miles of walking. I should have used a GPS tracker on my phone to be more precise, but on the way back to the hotel (half mile) I ran out of juice. This is the 2nd trip that this has happened and will be the last. I've decided to scrap the idea of changing motors and focus on batteries, controller, and charger. I'm getting caught up to speed now on the boards but if anyone has any products or if there's new threads I should check out please let me know.
-Andy