Yeah, I dig it, 24v stuff is what you have, so use it. 24v lead battery is so affordable.
I just meant to say that you aren't married to 24v by the motor itself, or the stock WE controller. That motor works best at 36v. At 48v, a bit of a tendency to overheat, or at least pit the brush commutator if climbing steep hills, partly because of the large 26" wheel.
I started out with two of the WE motors, (two bikes) and put a few thousand miles on them at 24,36,and 48v. I bet that motor would really perk up, and run cool if you relaced it to 20", then ran 48v. But what you have is working great, so keep on cruising.