9V Battery Rechargeable Lithium 400mAh, USB Charged, Overcharge Protection, with USB Cable /2Pcs

I bought these almost a year ago and thought they would be great because I have 2 smoke detectors so 1 battery for each. Fully charged them both but only used 1 because the other detector had a decent battery still in it. After a load of burnt grease smoke from my oven poured out earlier I wondered how the alarm didn't go off. So I pressed the test button and nothing happened, dead battery. Then I grabbed the other one I had charged and tried that... didn't work either.So for a start, every other battery when running low causes the detector to beep every few minutes until you change it. This one didn't. Then secondly if you charge them and leave them they run out on their own, yes I know batteries do that but I thought it would have held at least a little bit of charge.It was negligent of me to rely on them and not press the test button frequently like I am supposed to (won't be making that mistake any more) I am charging them both again now and will test each week to see how long they last and may update review based on what happens but be warned bout them.

I bought a pack of two to use with my TENS machine which I use daily. You should put them on charge as soon as you get them and it comes with a double headed charging cable but you can also use a Samsung type phone charging cable too as the slot on the battery is exactly the same as Samsung chargers.It took just under two hours to fully charge them, which is amazing if you compare it with regular rechargeable batteries which can take about 8 hours or more. They are so convenient to use as you can charge them anywhere even in the car, laptop etc. One of the best products I have ever bought.

These rechargeable batteries were a real bargain. They charge quickly and seem to keep their charge quite well. I had bought a pack of two because I was worried I would need a backup but so far I’m using only one of them in a measuring device (so not too demanding, possibly). Each battery comes with a short mini USB cable. I have enough charging cables but since this one so small overall it fits into any small pocket and useful for charging on the go.

Lovely output voltage of around 9.5 volts, and just what you might expect from a well made Lithium battery. It even has an led light to indicate charging-in-progress. No separate charger needed, as all that stuff is built in to the PP3 size case!!! Normally, each lithium cell gibes 3.7 volts, so I do not understand how thet designed it to output 9.5 volts, which is neither 2x3.7 nor 3x3.7 volts. A mystery!!

Love love love these little rechargeables - they do not take long to charge roughly a couple of hours and are ready to go once the little LED lights go out- so far these are lasting longer than normal batteries and they definitely get my vote.

Very pleased with these. Had them a couple of months now in regular use. They’ve not let me down.... and they are super neat.

Excellent idea. Bought two for my sons microphones. I am sure I will save money in the long run if they continue to work as well as they do so far.Will keep you updated

Great item, just as described and speedy delivery service too!