This is the one I bought (not affiliated with them): https://smile.amazon.com/gp/product/B082NN972S https://smile.amazon.com/gp/product/B082NN972S I called up

This is the one I bought (not affiliated with them): https://smile.amazon.com/gp/product/B082NN972S https://smile.amazon.com/gp/product/B082NN972S I called up the seller to buy more spare batteries and they said the 2 batteries the chair comes with, are under warranty for 1 year. And they should last another 2-3 years easily even with heavy use. So there's no point in buying spares now since the spares will lose the ability to charge over the same time. We have been out for 2-3 hours per trip many times this year and not once has even one battery run out.