If it is not being charged at the time of those messages, it is most certainly bad.
I can only go by the things you post, I can not see over your shoulder or (like Amazon) channel into your mind.
Nowhere do you mention what model Kindle you are writing about and your info block mentions a K3 and a PW3.
So how was I suppose to know if the Kindle you are writing about is still in warranty?
Did you see this line in your cut and paste?
Code:
170413:075145 [38359.733251] KERNEL: I pmic:fg suspend battinfo:current=-51mA, volt=3766mV, capav=027%, mAh=451mAh:
And this one:
Code:
170413:075145 [38359.983968] KERNEL: I pmic:charger chgina::charger connected
Which occurred about 2/10's of a second apart.
Either you are extremely fast plugging it in, or it was on the charger when it resumed.
I stand by my answer to your thread topic, your battery is really bad.
How you go about changing that situation is your own business.