I run a club at my school and we got the gopigo a couple weeks ago. While testing the Ultrasonic sensor, I thought I felt heat coming off of one of the metal cylinders. I touched it and it felt fairly warm, then I reached around the back and I felt one of the soldered parts on the back and it was incredibly hot. I unplugged it and let it cool. We had it plugged in with the wall AC adapter during the test. After it cooled down, I tried it with the batteries and after about 10 minutes I didn’t feel any heat. I checked to make sure the sensor was plugged in to A1 and it was. We believe it has something to do with the AC adapter, though I don’t know how long I had it plugged in before it got as hot as it did. If it would have taken longer than 10 minutes then we wouldn’t have noticed the issue with the batteries. I will test the sensor in a bit to make sure it works still. I don’t know if you ship different AC adapters but I will leave the model number and other information so that someone might be able to check and see if it could be the AC adapter. I’m not incredibly knowledgeable with electronics and circuitry so any help is appreciated.
Model number: FYA05010US
Input: 100-240v - 50/60Hz 0.6A max
Output: 5.0V 2.0A
Edit: I just tested the sensor and it still works fine and it isn’t heating up using the battery pack.