I'm exploring 24-48V power supplies for various personal projects, including powering motors and charging my homemade battery pack. I've noticed that many power supplies, particularly those from certain brands on Amazon, have warnings in their descriptions stating things like 'Not suitable for battery charging, speed controlled motors, solar controls.' Does this mean that using the power supply for tasks like PWM control of motors or charging batteries could damage it, or is it just poorly worded?
3 Answers
I’d guess these cheaper models lack proper short circuit protection. Motors and flat batteries can draw significantly more current initially, anywhere from 10 to 100 times normal levels, which can appear as a short circuit to these power supplies. If they can't limit the current, they might get destroyed fairly easily.
Some power supplies are specifically designed to match the batteries they charge. If they lack a solid charge controller, they rely on a certain level of source resistance to reduce voltage at the start of charging. If the power supply doesn’t have enough regulation, it can potentially damage the battery by delivering too much current, depending on its chemistry.
These warnings are often just poorly translated phrases that get copied across different products. Most of these power supplies will actually work for various purposes, but you should be careful because they are cheap and can fail easily if overloaded. When using motors, it’s pretty easy to push them beyond their limits. Higher-quality power supplies usually have safety features that will shut them down rather than allowing them to break.
So, it sounds like there are no fundamental issues with using the PSU for those tasks, but additional electronics are needed to ensure it’s done safely?