Flip 4 battery change July 8, 2019 16 32 64 128 Jbl flip 4 battery change Z flip 4 battery change Samsung flip 4 battery change Samsung z flip 4 battery change Flip 4 battery Flip 3 vs 4 battery test Z flip 4 battery drain test Z flip 4 battery charging test Z flip 4 vs z flip 3 battery