This is the lowest price I've seen on one of these LED power supplies:
I have one and have set up several for others, including one on the bench being modified right now.
They are a very nice DC power supply with adjustable voltage. The little potentiometer to the right of the terminal strip adjusts the voltage. One needs to simply attach a wall plug cord to the three 120 volt (or 220 if you flip the switch on the side) and attach jumper wires or plug to connect to the bike. This one makes up to 25 amps which is great for doing testing and battery charging.
Want to test those new grip heaters to make sure that they work and don't quit after a few minutes? Put a voltmeter across the jumper or DC plug, adjust the potentiometer to desired voltage, connect to bike and it can be left powered on all day. The only reason to adjust the voltage is if you are doing something which wants lower output like maintaining a battery when it might be better in the high 13 volt range than mid to high 14's.
Mine is the harder to find type with adjustable current also but that's no advantage and extra complication for most people. One can wire an LED voltmeter and ammeter + replace the little potentiometer with a panel type for convenience if doing much adjustment but most people will simply adjust once and good to go.
These are self limiting in terms of current so will just shut off rather than burn out. Only problem I've experienced is hooking the 12 volts up in reverse which blows the little fuse inside. Only done once and if to again will wire in an external fuse holder.
Happy to help if someone wants more information. These are on Ebay and other places also. I haven't bought this one but looks the same as the ones off Ebay.
I use mine for charging odd stuff like 6 volt batteries on old trail bikes and running various odd electrics also.