When the External Battery Slows Down The Keyboard

A few weeks ago, I wrote about the great autonomy time that 130 Wh USB Power Delivery Battery gave me for my notebook while traveling. The only disadvantage of the solution is that the battery weighs 600 grams. So I thought I’d get another, somewhat smaller and much lighter USB PD battery with a capacity of 37 Wh. This would just be enough to feel comfortable in many situations. And while the external battery works just fine with a number of USB PD capable notebooks I tried it with, it has an interesting quirk in combination with my main productivity notebook: It slows down the keyboard and makes it miss characters!

Yes, I kid you not! When connected to my Lenovo X13 notebook, everything looks fine at first, the notebook charges from the battery as expected. However, I soon noticed that every now and then, characters I definitely typed on the keyboard did not appear on the screen. When looking more closely, I could reproduce this behavior and I noticed that the keyboard response was markedly slower than normal. When removing the battery, everything was fine again. Plugging it back into the USB-C port of the notebook, and the keyboard started acting up again. I had a look at the kernel log, but there’s nothing out of the ordinary. So I’m really at a loss of how the battery plugged into the USB port could influence the keyboard!? It’s even more of a mystery, as my other USB PD battery works fine, and because I can only see the effect on this notebook and not on others. If you have an idea what’s going on there, please consider leaving a comment. (Note: Due to ongoing massive comment spamming, see my email address in the about me section)