I've used a WPS lithium battery in a scooter. It worked great until I killed it over drawing it - entirely my fault and it was replaced under warranty. For fun I opened up the dead one, mostly empty space in the box in the one I had - the lithium cells are very small. It had an internal cell balancer and I think WPS states that a dedicated lithium battery charger wasn't necessary but that info comes with the battery so don't take my word for it. How would a regular charger be worse than charging off of stator anyway? I never understood that. I use a battery tender to top it off once in a while but they hold charge for a long time and the WPS has a charge indicator so you can check easily.