HW 9V Batteries for Smoke Detector Alarm, 2 Pack Rechargeable 9V Batteries Pre-Charged All-Purpose NIMH Batteries, 1000 Cycles 9 Volt for Home Battery Backup Supplies Square Batteries

These rechargeable 9-volt batteries run my metal detector for the longest time. I can look forward to a repeat performance after I recharge them. It's a win-win deal for me.

Everyone wants to pay a little less and, let's say, "cheat fate" a bit. Plus, let’s remember the environment! To reduce battery waste, what do we need to do? We need to recharge them. Of course, regular batteries aren’t rechargeable, and this brings us to the product in our review.Even though these batteries might seem like a great buy, don’t get too excited just yet. The thing is, they have a very low capacity of only 200 mAh. This isn’t exactly a flaw but rather a feature of these batteries, and if you’re buying them, you need to be clear on what they’re meant for. In simple terms, these batteries aren’t suitable for high-power devices like walkie-talkies, microphones, or guitar pedals. But for smoke detectors, they’re ideal, as these devices don’t require much power.I’ve tried these batteries, and they've been working in my home smoke detector for several months without needing a recharge. Plus, while one battery is in the smoke detector, the other can be charged. The manufacturer claims they can withstand up to 1,000 recharge cycles, though it's unlikely that you’ll ever need that many in practice.In the end, we’re looking at nearly everlasting batteries for about the same price as two from a popular brand. Not bad, right? Just remember what I mentioned earlier, and don’t forget the charger.

Worked as described. Good cost for the price.

Getting tired of buying 9 volt batteries, I decided to try these. I have tried other types of rechargeable batteries, AA, AAA, etc., and have had good luck. The added expence of getting a good charger might be a drawback. I believe I have recharged one of them a least once. They do not seem to hold a charge as long as alkaline batteries,but I don't have to buy batteries all the time

I used this product for my smoke detector and it works great.

The rite price.

These batteries tested 9.1 Volts out of the box - an indication they hold a charge well. After charging they tested 10.8 Volts right off the charger - and dropped down to 9.8 Volts 12 hours later. This indicates they employ 8 Ni-MH cells which is good. Some 9 Volt Ni-MH batteries only use 7 cells and they only provide about 8.5 Volts in use. So these batteries look good. I will use these in a metal detector. The last NiMH 9 Volt batteries (another brand) I bought from Amazon lasted 12 years - I hope these do as well.

These are real 9 vdc rechargeable batteries--but that means they will run low power devices like smoke alarms, but if you need the regular 8.5vdc rechargeables with power (but can't be used in smoke alarms), then don't buy these. The product is good and labeled correctly, but no good for what I needed. I guess these are for smoke alarms and other low power devices. 200 mAh's is almost nothing.