2Pack 6.5Ah 24V Compatible with Greenworks Battery 29842 29852 and Replacement for Bissell 24V Battery XR 4054 Battery for 3789U,3797V

If you want genuine GW parts (to keep your warranty valid) then this pair from Walmart is a good deal - they are compatible with your tools and charger, and double as power banks If you want to experiment with aftermarket (potentially risky) then these from Amazon seem like a deal and might let you finish mowing without having to swap batteries