9v Battery Eliminator (9v DC Adapter & Battery Eliminator) - Replace Your 9-Volt Batteries with Wall Power Supply

I've checked, and if the two-part plug-in substitute for a 9v battery is used as a kit there shouldn't be any polarity problem. The AC/DC converter plug prongs are reversible, because AC cycles back and forth, and for this purpose the converter doesn't care which prong the AC comes from. The DC polarity at the point of connection where the the adapter attaches instead of the 9V battery will always be right -- male pole positive. The seller explained to me that polarity can be wrong if an AC/DC adapter with a purposefully different DC polarity -- like for a guitar pedal -- is substituted for the converter that comes with the 2-part kit.

I bought two sets of these battery eliminators and power supplies to use for a couple old DOD FX series guitar pedals I bought recently. Since the power port on the pedals was old and obsolete, I decided to use these to attach to the battery connection. They worked well in powering the pedals and did not hinder the sound as poor power supplies can. The shape of the plug was also nice since I could fit the two on a power strip side by side. I cannot comment on the longevity of this product since I have had these for less than a month, but the longer they last, the happier I will be with them.

It is performing as it should no issues with the product. Would recommend.

I've decided to use mine on just one device, my digital scale, because it kinda burns through batteries. If I need to take it for something else it's always there, but yes you can turn a battery-powered device into a corded device and stop buying batteries for all of your devices that use a single 9 volt battery.Good for your wallet and for the planet too.

I have a set of Bunker Hill (Harbor Freight) infrared sensors set up by my front and side doors (in windows, not outside). Anyway, seeing as there are plugs nearby them, I figured I would try a battery eliminator in one (trial run). I did check the polarity with my tester before use, it was correct. Works like a charm. I did make a little notch in the battery cover for the wire to pass through (looks better than leaving the cover off). I also made a loose knot in the wire, behind the cover (in case it got pulled accidently). I have recently ordered another for the other sensor. If I remember, I will update on longevity.Edit - I forget to mention the cord (on the one I received) is 44 inches long.Edit - I needed to extend the power cable on my second battery eliminator (didn't want to use an extension cord on the adapter). I purchased this https://smile.amazon.com/gp/product/B01MUH5QF4/ (white to match the window), works perfect.Edit - Feb 23, 2020. The two I bought are still working fine.If this review was helpful, please click 'Helpful' below (lets me know that I'm not wasting my time, by doing these). Thank you!

The convenience, and cost savings make this worth the $10 it cost. It keeps my digital thermometer running without a problem.There are two issues with it:1. The red LED on the power block is very bright. I'm not even sure why it needs a light. Easy to fix with a piece of electrical tape to cover it. It still has a little bit of a glow, but not bad.2. It emits a high pitch whistle sound. At this point even cheap power supplies run quiet, so this is not great. I may have just received a bad one, but I can live with unplugging it when not in use.

The 9 volt output on this battery eliminator is a generous 1/2 Amp (500 milliamps). A typical rating for a fresh 9 volt Alkaline battery is 550 milliamp hours; which means you can draw 550mA for 1 hour - or - 55mA for 10 hours (the same amount of total energy). In other words, this battery eliminator is capable of operating a device which is so power hungry (55mA) that it would use up a brand new 9 volt Alkaline battery in 10 hours. Ample power! Additional note: I found the in-line connector to be a welcome enhancement. It readily enables the separation of the device from the cord.... Hope readers find this useful info...

I bought this for my home studio that serves as my Virtual station for work. I bought this to eliminate the need for 9V batteries. This absolutely has not worked for me. I didn't return it with the hopes I might someday get it to work and it's a great concept, but for the boom stationary microphone I purchased it for, it is nothing like the electric options you get with a AA option. I would not buy this again.