We have 3 phones, 2 Galaxy S5, and 1 Galaxy Note 4, that are 92% paid for and we are eligible for upgrade. our phones worked great for the past 2 years. the occasional blip (the pop up drive me insane! I go to use my messaging app or any app for that matter, and I get redirected to my browser for a pop up---Clearing cache and having all apps on wifi use only does not work, I clr my history daily) Back to Point. Since upgrade, my phone only works if it is plugged into a wall, essentially making it a portable landline. I unplug the phone, maybe get 1 min of use then it just dies, and cycles thru the dyeing process. I plug the phone back in, and the green battery gauge says 57%, 84%, or just completely drained, after it had literally just been at 100%. We pay an insane amount a month and I barley use my phone. My daughters just went completely dead, no charging it even with a new battery and factory cords, she now uses her old S3, (while I am still paying for S5!!) My husbands Note 4, does the same thing as mine. He takes it off charger and within minutes it either just dies when he opens an app, or the battery reflect a ridiculous %, like 42% or 12%, again he also has a new battery and factory cords, as do I. We all have insurance on our phones but that is 100.00 bucks each just to get a replacement if @verizon even approves it. We just feel so cheated and bullied into getting new phones or upgrading. It is very strange that Once we become eligible for upgrade and ALL our phones start acting strange when we get so close to them being paid off.
It's weird for it to be the same issue on all devices and makes me think you should look into the chargers you are using and if they are all OEM, I'd look into where you are plugging them into the majority of the time; wall socket. Maybe try charging them on a car charger, or multiple wall sockets, different house etc.
Personally I wouldn't pay for insurance, unless you are prone to breaking phones. You can get a used S5 for $100-$160 and all you're getting when you pay $100 for a "new" phone from Verizon is a refurbished phone. Add that with what you've paid monthly for insurance and you'll spend $364 in 2 years if you use your insurance once. $364 could get you a gently used S6 with cash to spare.