True. And a couple other points from someone invested in the Milwaukee ecosystem (which I assume are similarly true for Dewalt and others). The batteries are co

True. And a couple other points from someone invested in the Milwaukee ecosystem (which I assume are similarly true for Dewalt and others). The batteries are common enough that knockoffs are readily available. This would seem to be the objective - competition among battery suppliers. The problem is the off-brand batteries are hit and miss at best. I still have the first two M18 batteries I bought at least twelve years ago. They've been charged countless times and are still going strong. The branded batteries are annoyingly expensive, and yet worth the money in my experience. On the other side of the equation, there are plenty of off-brand accessories that utilize the batteries. I have an LED shop light that uses them, for example. And beyond that there are little adapters that attach to the batteries with wires that let you power whatever at 18v. My kids just participated in a power wheels "demolition derby" last weekend (they attach balloons to the power wheels and the kids pop each other's balloons). Both of their power wheels were borrowed from different people, and both were converted to run off Milwaukee M18 batteries. I'd wager most of the rest out there were too.