Both batteries fully charged but one fires the Spark right up and the other refuses to. Defective battery I think, has anyone else had this? I have the Spark fly more combo with 2 batteries.

Sir, can you turn on the other battery or charge it? Please install it on the spark and check if there is any message from the app. Thanks for your support.

OK I will do that. Battery in question shows full charge.

And yes it turns on...

Always best to return defective batteries even if it suddenly starts working - you don't want that disconnection when happening.

True I will be doing that. Though I did a reboot on the iPhone and now the battery is working again. I am slowly figuring this thing out but I definitely want more batteries. Does any place stock them in Hawaii?

Hi. you might check with our pre-sales team. Here's the link. https://www.dji.com/support?site=brandsite&from=nav. Please select Online support. Thank you.