A:AnswerYup, sure is, the hero 6 and the 5 both share the same housing and accessories. There's only a spec difference between them. If you have a hero 5, the batteries are interchangeable with the 6.
A:AnswerThere are too many factors to that to answer properly. If you are recording in 4k at 60fps....maybe 45 minutes per battery. Lower resolutions and fps last much much longer. The batteries dont weigh much. Get the dual charger and a few extra batteries and you should be good.
A:AnswerNo, the Fusion camera uses another size of battery.
Find it here: (Best Buy) https://www.bestbuy.com/site/gopro-rechargeable-lithium-ion-replacement-battery-for-gopro-fusion/6186305.p?skuId=6186305&ref=212&loc=1&ksid=30242f3e-307c-4c40-ad53-e55042ebaea5&ksprof_id=14&ksaffcode=pg174438&ksdevice=c&lsft=ref:212,loc:2
