this sounds a bit strange. The charge time estimate is more of a guesstimate. More importantly does it charge, i.e. does the charge increase over time? I hope it does! As soon as the power LED is green the charger should be enabled and the percentage should go up. The speed of increase varies a lot depending on the use case. Worst case if you really stress the system at max. power with peripherals attached the percentage may even fall though the charger is connected. But with normal use or best in standby it should increase over time. How long it will take for a full charge then depends on the previously described use (and power budget).
Concerning the regulator noise you are hearing, I am sorry for that, this seems to be a minor regression with the latest EC firmware update we did. We experience some issues with some, few, laptops where the hardware actually breaks, i.e. they will still work from battery but do not accept power input from any charger (barrel or type-C). We did a change in the EC firmware reverting a change that we implemented at the time when we think these issues started. So we wanted to make sure that this change is not the cause. This change reintroduced two problems it seems, a possible sudden power off if the system uses a lot of power but the battery is at low percentage, the other is the regulator noise you are hearing.
Maybe a word on this type of noise. In modern electronics a lot of different voltages are needed. Back in the day the voltage level was +5V DC TTL, simple. But not anymore. To generate all these different voltages so called switching regulators are used. These, very simplified, consist of a regulator controller chip, a MOSFET transistor, a coil and some filter capacitors. The coil is driven using the MOSFET switching transistor at a regulated frequency and eventually under PWM, i.e. very quickly being powered and not powered. The coil contains a small core made of some ferrite alike material, so the coil plus its core get electromagnetically charged, the discharge is then used for powering the circuit behind it. The regulator chip very carefully regulates the frequency/PWM in a way so that the output of the coil matches the desired voltage. So the real current is flowing through the MOSFET and the coil. The MOSFET is a silicon package, very tight. But the coil is a mechanical thing - there is the ferrite core with some windings of some wire around it somehow etc. Depending on the current / energy driving and discharging it the coil is also put under mechanical stress, there are significant magnetic forces now inside it which can cause the material to be pushed apart or pressed together. The result is, even if tiny, a small movement of a mass. When a mass starts to move at a certain frequency also the surrounding atmosphere starts to move - you have a tiny speaker.
So depending on the switching frequency, the PWM and the mechanical stability mostly of the coil you can hear noises, if the frequency or its derivatives are close to the audible spectrum. The sound varies with the frequency and the load on the coil. So under certain circumstances there can be audible noise, it may sound differently in other use cases and may not be audible at all in some more.
That being said, with the last EC firmware change we removed a limit we previously set on the Intel package power consumption - we had assumed this limit might have been too high and went back to the power on reset default. Sadly all that is very badly documented in public Intel documentation (we are talking about so called PL3 and especially PL4 here). With this change we very obviously changed the power consumption of the Intel package which, in some laptops, causes worse regulator noise. Nevertheless we wanted to push this change out quickly in order to avoid more main boards from breaking.
By now we figured out through painful testing and more experiments that this change is likely not the root cause for the failing boards. We have already made a new EC firmware release 1.7 and put new defaults for PL4 back in. We tested the default we have in there now to not detriment performance while still limiting power enough to be safe® for the main boards. This will also reduce the regulator noise again as well as help to prevent many of the “sudden shutdown at low battery charge”.
This regulator / coil noise is really super hard to control, it has to do with a lot of things. We have already implemented what we could to mitigate effects in those spots where we can implement something - e.g. the charge controller for the battery has a special mode that will avoid audible frequencies, which we enabled. Most of the other regulators we have no control over from software. We are also seeing quite some spread between individual devices. Some devices almost do not exhibit this at all, some others are clearly more audible. This also has to do with a certain spread in the mechanical stability, mostly of these coils. These are pretty mechanical components, there are tolerances. We have some hints and ideas for reducing the effect that we are also researching.
So, if you can, please upgrade to EC firmware 1.7 that should help a bit with the noise. And please watch the charging, it shoulg go up when not stressing the laptop and the power LED is green.