what does it mean if the sign of battery remains low in red after 1 hour of charging?
iPhone 6
Potentially, it could mean that this iPhone's battery has passed it useful life. Is the battery the original one that came with this phone?
You may find the following support article helpful: If your iPhone, iPad, or iPod touch won't charge - Apple Support
Apple considers that an iPhone battery needs replacement if it cannot maintain, at least, an 80% charge after 500 full recharging cycles. If this is the case for your iPhone, then you should consider getting it replaced by Apple or an Apple Authorized Service Provider.
Ref: iPhone Battery & Power Repair - Apple Support
Thank you for your reply. Yes I think it is the original battery. It has been specially the last few months on a shorter charge cycle, and suddenly jumping from 75% charge to 20 % in a few minutes.
my iPhone 6 is charging for an hour and still showing the sign of low battery in red
