Why is Tesla (Battery) Making Humming Noise while Charging?
1. Humming and whirring sounds
The humming whirring sound coming from your car as it charges from a120v wall outlet/mobile charger is normal and is part of temperature regulation. Clicking or thunking noises while charging are also normal. They emanate from opening and closing valves and pumps moving coolant around while the BMS is charging.
A Model Y makes very little noise while charging to bring the battery up to temperature. It is on the same level as a fan. The noise from your fans and heat pump cannot be heard from more than 5 feet. You charge your Tesla at 10kW and you have option of adjusting it to charge slower if you want to reduce noise.
2. Gurgle like grinding thumping sound
When you enter, park and start charging your Model S you might experience a strange funny sound coming from the front bumper area.
It is similar to the sound you make when you sit and sink into a deep leather couch. This gurgle like grinding sound comes from the center of the front bumper.
It gets worse in cold temperatures and can be heard when you plug in and find that your battery is cold.
You will also hear thumping noises on the bottom. These noises indicate that your battery was close to freezing and they increase as your battery is heats and expands to facilitate faster charging.
3. Constant buzzing
When your car is woken up or is charging it makes a constant buzzing noise that can be annoying. What is this noise? Well, it’s a louver closing.
You will hear this sound when the louvers in the cooling system activate, and the compressor or fans turn on as the battery warms up.
If you take your Tesla for this issue to the Service Center, they will rate this noise as a normal sound was and recalibrate the louvres as a precaution.
4. Snapping Sound
Right after plugging in your Tesla in a High-Powered Wall Connector, you will hear a normal buzzing sound which will worsen and then morph into loud disturbing plastic snapping sound.
This occurs a lot especially in low temperatures or when your car is packed with snow and the air vents openings get a little sticky due to the cold weather and ice.
This can also happen a lot to you if you plug in to charge at home. What is this sound?
This is a louver closing in front of the air inlets.
The front radiator louvers open as they expect a hot battery and close again after some minutes when your battery warms up.
Service might not address the louver noise as a problem, but they can check to see whether you need a compressor replacement if your warranty is still valid.
5. High pitched buzzing in rear motor, clunking and banging
When your electrical vehicle is plugged in especially after completing a software update you will hear a strange sound- like an angry mosquito like noise. This piercing noise will be coming from your rear wheels. It is very normal.
It means that you may have air in your coolant system. The coolant flows via the pump to the battery pack. The pump turns on for charging and battery heats up making this sound.
If you don’t feel comfortable with the sound open a service ticket and send the video to Tesla service for troubleshooting.
5. Knocking and banging sounds
You will hear knocking/banging noises you during software update when your Tesla is plugged in but not charging as contactors open and close.
Software updates affect HVAC/Cooling/Heating systems, BMS, oil pumps, contactors, DC/AC inverters is put into effect. Your car will run fans, pumps, coolers and so forth at a really high rates there will be a lot of weird funky noises.
This is totally normal, but if you don’t like it, you can unplug your Tesla while it updates and charge it afterwards to see if it changes the sound?
6. Whining
A clunking noise is normal, but whining noise in your Tesla could be a problem and you should definitely get it checked out. A heavy loud ramped up whining noise only occurs when your car is pre-conditioning the battery as you use the navigation to go to a super charger.
7. Silence
There’s no sound when a Tesla is charging at home. This electrical vehicle can emit some random sounds like whirring, clicks, clunks while sitting still, but when it is charging it is quiet.
You will hear is a very slight electronics hum whenever the car is awake but when home charging it will be silent or virtually silent.
If you run charging in an enclosed garage will hear this hum due to the compact space but you will hear nothing when your Tesla is parked in the driveway.
When you place your phones on the grill of the car the hum is very loud because microphones are sensitive.
The loudest noise you will hear when your car is charging is the clunk of the relay in the charger engaging.
The electric car produces sound that is no louder than crickets chirping or a gentle breeze through the trees as home charging put out only 5% of the power emitted from a Supercharger. Therefore, your Tesla barely needs to cool the batteries thus no noise.
In fact, for you hear any noise from fans or other components in your Tesla you must be within a couple feet of the car.
8. The infamous ‘thunk’
This is the most common sound in a Tesla. It is completely normal and is heard when changing to higher elevation in cool weather, or driving up hills, through mountain roads or any other rapid altitude changes.
You hear this thud because battery is charging or discharging rapidly or while ascending and descending up and down long hills and the battery breather valves releasing pressure.
Your Tesla will make loud thunk sounds while charging at the Supercharger charging at 250kW.
Superchargers pump up to 600 amps of 400V DC which generates a lot of heat a prompting your car to maximize all its cooling fans and pumps and resulting in a very noisy car.
The thunk presents as a loud popping noise and rumbling from underneath the vehicle but this is completely normal. It feel like explosions through your Tesla car seat.
If the thunk sounds bother you, don’t run your battery to low, to prevent high supercharging rates that reach the high charging speeds causing the thunks.
The thunk only affects pre- 2020s models which have an older VIN. This sound is caused by a valve opening in response to the heat buildup in the battery while supercharging. Tesla changed the valve after 2018 to one that does not produce a lot of noise.
A thunk can be caused by metal contracting and expanding. As the metal flexes over and over again it gets weakened and results in fatigue. The wear and tear can also arise from heat expansion and contraction.
Finally, a very short rare thunk during charging is not a defect but a normal occurrence and does not affect performance. Your Tesla is cooling the battery down and this cooling system is what keeps the battery and rectifier safe.
This is normal as there are large terminals switching between battery packs and it does not affect the HV battery in any manner.
9. Popping and thunking is not normal for model 3
It is crucial to note that popping and thunking noises during supercharging or high altitude driving are not normal in the Model 3.
Tesla released a service bulletin Bulletin SB-19-16-010 to resolve this issue for any Model 3.
They admitted that the battery breathers they started using in April 2018 were incapable of equalizing air pressure between the inside and outside of the battery smoothly.
In essence, they said that when the air pressure changes a lot e.g when charging or from driving in high elevations the air pressure suddenly equalizes, leading to a popping sound.
They came up with new battery breathers designed to improve the process equalizing air pressure smoothly and to remedy the popping and thunking sounds.
If you wish to correct this defective part for your Model 3, create a service appointment referencing this Service bulletin for your battery breather.
Though this replacement will not eliminate the popping and thunking sounds completely, it will significantly reduce their occurrence.