Battery drain and fast recharge

I have an ipad 9.7 pro (2016) my battery completely drains in about 2 hours or less with web search. Strangely it then takes only about 2 hours or less to charge back to 100%. Battery test shows good battery. No large battery use from any installed apps. Only game installed is solitaire. Brightness less than half, True Tone off and auto-lock 2 minutes and lock/unlock on. Have done all recommendations to stop battery drain including erasing all context, settings and starting a new. Not sure if it is worth it to get a new battery could be a hardware problem.