For those looking at batteries Odyssey now do a GRP24 76Ah battery. Its STILL 17mm too wide at the top for some chairs. 277mm instead of 260mm and it baffles me why they do that. Theres no battery inside those top bits that make it longer.
But if your chair allows you to fit one it even outdoes the PC 1500 version. For everything. Its literally the best battery you can fit to a powerchair for range, lifespan if charged properly, and has the lowest internal resistance and highest reserve time of any battery you can fot in many chairs.
https://eu.odysseybattery.com/products/ ... 4-battery/
Dont expect these cheap. They make no sense when you can fit 4 to 5 times this range, 200Ah, of lithium for around 70% extra. And also get a battery that will outlive the chair and many of us. But if you want lead...