Sometimes noticeably warm after an overnight 120v/12amp charge

[MoldyWalnuts]

i have a '16 Spark EV 2LT with 48K miles, production date June 2016, getting about 100 miles to the charge in the city and 80 or so on the freeway. lately i noticed that, not all the time but, sometimes the front of the car, grill/hood/fenders, gets noticeably warm to the touch after an overnight slow 120v/12amp charge. perhaps i catch it at a cycle moment when it warms up for whatever necessary reason or there is something wrong... anyone else notice this on their car? this charging takes place overnight in a warm garage, nothing unusual in terms of ambient temperature, and i just noticed this in the last few weeks, after 4 months of ownership. sometimes quite warm and sometimes stone cold...

forgot to add, when it's warm i also hear some churning/sloshing/relay humming? noises, like when i first hook it up the night before. my guess is that the coolant begins to circulate when it's first plugged in but i don't understand this noise after an overnight charge in the mornings. all is quiet in the mornings when it's stone cold. i'm hoping that i just catch it at a normal point in the charging cycle when it cools the battery or something like that, this would explain why i don't experience this every time after an overnight charge...

thank you