Hi all, Not sure if anyone here is into tinkering with things to make them better, but I own a lot of Bosch 12V power tools. I love them for the combination of price/performance. I currently own the PS20, PS21, PS41, PS60, and FL12. I also own a lot of Bosch 18V tools. I set out to create a battery eliminator for the 12V battery. There are a few times where I am doing a lot of use and don't want to keep swapping or rotating batteries. So, I got some 12V barrel plugs and jacks, removed the cells from an old battery. I wired up the plug to a 12V / 3A AC-DC adapter. It measures about 12.25V on my Fluke meter. I originally came up with the idea for my FL12 work light (which is FANTASTIC), it does go through batteries quickly as there is no variable settings. It's full bright, all the time. The adapter battery works 100% the FL12 flash light, but on a PS20, it pulses for a split second then dies... and it keeps doing this with consecutive trigger presses until nothing happens -- The adapter I am using goes into a "shutoff" or "protect" mode. If I remove it from AC, wait 10 seconds, plug it back in.. it works again. Any idea why the PS20 won't just spin forever? There's only 12V contacts inside the tool, no temp or other wires connected. Does the AC-DC adapter need to be under 12V? I know the batteries are technically 10.8V but the battery I measured is around 11.5V. Do I need an adapter with more current? You can see the adapter I made here.. nothing special, just a DC jack at the bottom. https://www.dropbox.com/sc/h3b0k283h5zx5d4/AADQyJvKubip-iMqCxzgzdWfa BTW- I am an audio visual engineer, but my knowledge of how batteries work and power tools "think" is not my strong suite.