I have an off-brand scooter that's very similar to the Elite Traveler. It was very reliable for quite a while. Right before a DLR trip, I had the batteries checked. What I didn't expect was an issue with the airlines. Apparently they left the scooter on the tarmac while everyone loaded. Since it was a hot day, it melted the batteries. I didn't know this until we got home a week later. Ironically it still ran, though it didn't have the stamina it had before the trip. No matter how often I charged, it would only last around 4 hours.
Looking back, I should have found a place to purchase new batteries while we were there!