Uknown vibration when battery unloaded

Toyota prius 2009 gen 3, current odometer reading: 135000 km

I recently bought this car from netherlands, it was after a small accident, where I only needed to replace body parts and left headlight, + some wires from bumper,



This car was 131000 km odometer, maintained in an official Toyota dealer service, all history and stamps are present on the book + there are official document with odometer fixations proving that the mileage is real

After fixing the body parts I went for a technical inspection it passed without any issues at all, even the people that work there gave comments that its really nice and technically correct car

However, whenever I drive somewhere slow or in traffic and the battery unloads (it drops to 2/8 bars) the engine starts to vibrate intensively, it's really an unusual vibration i feel , after the battery is charged a bit, the vibration becomes lower, same thing happens when I just arrived somewhere and I press P without shutting down the car, so the battery eventually goes to 2 bars and the motor starts to charge it, however it doesn't ALWAYS happen, but a lot of the time, but it never happens when the battery has 3 or more bars,

I was very concerned and I don't want to ignore such vibration so it doesn't cause any further damage so I took the car to service for inspection, i thought maybe the engine mount after the minor crash was damaged or some part moved out of place, but they inspected and found nothing so they told me to come back when the issue becomes bigger, however I have doubts that they felt this particular vibration, because as I said it doesn't always happen., sometimes when I want to show it to my friends its not there, however there was times when it was there and they agreed that its a little too much.


Thank you for your help