9V Battery Eliminator Kit, 500mA AC/DC Adapter, Connector and 42in Cord

Solved the issue of replacing batteries constantly. So happy I bought this.

Works great. Helped me convert my 9v dc Gun Vault to ac. No more replacing batteries - or forgetting to replace batteries!

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.

It does the job but..... The connector between the power supply and 9 VDc adapter slides apart too easily. Fixed with a little electrical tape. Power supply wall wort gets a little warmer than I like. Otherwise good deal.

I never knew these were real. LOVE it! I can run my Geiger counter 24/7 now :-) on the self. I recommend the Ludlum 2401-P handheld pancake GM, very nice unit. Just make sure it gets ship GROUND ONLY. GM tubes should not exceed 8,000' alt. THEN get one of these to run it at home/office/lab :-D Very nice.

The product worked great! I was a little disappointed at first that the 9v adapter didn't seem to work with anything else that needed the same voltage and amperage. I was confused by this and then spotted this in the description: Please Note: Your Adapter Must Have a Comparable 5.5mm X 2.1mm DC Barrel Jack With Tip Center Positive Polarity This was the issue: most of my peripherals call for "tip center negative polarity". So I ended up also getting a polarity inverter so I could more easily use this adapter with other things and also use other 9v adapter with this batter replacer. I hate buying and changing 9v batteries, so this was a perfect solution for me!

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...

Bought this to replace the quick burnout of 9V batteries on guitar equipment with no plug interface. With a few modifications to the pedal battery boxes does a great job and works as advertised.

Love thus product. A little pricey but will eliminate the use of the 9v. When the weather gets cold so did the 9v. Then didn't want work.

So far it's working great on my exercise bike

The product is exactly what I was looking for. The connection mid-wire really helps in my application. The only reason I didn't give it five stars is that I haven't used it long enough. If it continues to function as well going forward, I would not hesitate to give it 5 stars.

It turns out that I can't use it without some modification. The TENS unit with 9v battery doesn't have terminal posts like a normal 9v battery installation.