The problem with those is that the device loses the ability to sense the charge status of the battery, since the voltage remains the same until it’s empty.
Besides being the wrong size by definition, AA batteries are expected to have 0.8V to 1.5V, while Lithium Ion cells (such as 18650) have a voltage range of 2V to 4.2V. That’s completely incompatible, you couldn’t even replace two AA batteries with a single Li-Ion cell.
Careful with attaching things connected to your skin with live. If there’s any fault, you’re going to be electrocuted, unless there’s an isolating transformer with good isolation in the circuit.
The focus is different. The Lemmy apps are trying to provide a good user experience, while the Reddit app is trying to cram as many ads as possible into the screen space.
This might be very specific to the US. Here in Europe, SUVs aren’t nearly as prevalent, and trucks don’t drive on the same roads as cyclists do. In my experience, when I'm going 30km/h, I’m no longer a roadblock for cars.
However, bike paths aren’t designed for the kinds of speeds you'd get with that thing. I'm driving an e-bike, and I have to brake to a near standstill whenever I get to a bend in a bike path, because for some reason the planners think that bikes can turn on a dime. Also, in my city we have a lot of mixed bike/pedestrian paths, and pedestrians don’t appreciate it when you drive by with 30km/h within a few centimeters. I've also had people who froze like a deer in headlights when I approached.
The costs feel extremely low to me for such a project. In my country, just the greater area around the city I'm living in received a €677 Million investment for train infrastructure in 2020. The next few years this will be spent to increase capacity in a small area that already has infrastructure.
Regular brand LED bulbs don't strobe at all, only the very cheap ones from AliExpress and the resellers of Chinese crapware (like Walmart) do. IKEA has some nice and cheap bulbs, for example.
Well, we saw what happens when they need to catch up: they buy up their competitor.