9V 850mAh Rechargeable Batteries and Charger,Kratax 9V PP3 Lithium-ion Batteries,Low Self-Discharge High-Energy Battery with 600 Cycles,[4 Pack Batteries +1Pack Charger]

Had rechargeable NiMh 9v batteries for some time, okay for toys but a pain for stuff on the ceiling (smoke detectors)... not enough capacity means regular battery changes due to low voltage beeps. These lithium rechargeable claim a whopping 850mAH, which I can't measure, but they have massively outlasted my previous NiMh in higher drain devices and the low drain ceiling stuff are just fine. You do need another charger, supplied, but it is neat, compact and solid. Individual charging and LEDs lights to show when complete. Arrived with a good charge quickly topped off and all good. Rechargeable batteries are an investment, so far, this is a very good one. Like when the eneloops first arrived, this 9v technology seems a bit of a game changer.

Great Value, Quality Batteries and Compatible charger suitable for the application.

I bought these to run a BeechBox DSLR sound adapter with phantom power mic inputs, that is notoriously battery-hungry. Although these sit initially at a lower voltage than fresh alkaline cells - 8.4v rather than over 9v - and probably have less absolute charge capacity in mAh, their output voltage doesn't drop below the usable range so quickly - even though they don't seem to have an internal voltage converter to keep the voltage up as the lithium cells discharge, the discharge profile is a lot more useful for devices that actually need over 6v to function, especially devices that draw a hefty current. With an alkaline cell, a demanding device will have it down below 6v long before its actual capacity is exhausted, with these, even when totally discharged they're still around 6v. The BeechBox, for example, will work from an alkaline PP3 for about 2hrs, whereas one of these litium rechargeables will power it for 8hrs. There are two lithium cells in series inside, and they typically vary between about 3v per cell dead flat to 4.2v per cell at full charge. They shouldn't be depleted below 3v/cell or they will be damaged. Cut-out circuitry attempts to make sure this doesn't happen. When charged, they retain charge for a decent long period, and in a very low current application like a smoke detector, although their fully charged voltage is borderline for that, they will work happily for a few months while you get around to buying another alkaline (which are better suited for super-low current things like smoke detectors). Not the most expensive lithium based rechargeable PP3s, nor the highest capacity, but usefully better than many, and I have no complaints at all at the price. The supplied charger requires a 12v-ish PSU, and works fine. I've had these for some time now and they seem to be lasting well.

I was initially looking for non-rechargeable 9v PP3 lithium batteries for use in multi-meters and other portable test equipment. I have in the past had devices damaged (sometimes beyond repair) by leaking alkaline and zinc batteries. I have tried NiMh re-chargeable batteries, which give me the leakage peace of mind, but often let me down due to their relatively low capacity, and considerable self discharge (the AA & AAA varieties) are much better in this respect). On discovering these Kratax re-chargeable lithium batteries, I figured that they would give me the leak protection that I desired, and because of the much greater capacity, and lower self-discharge properties than NiMh batteries, they should prove more reliable in practice. I ordered the set with the charger, as my charger is a smart charger designed specifically for NiCd and NiMh batteries. The item arrived within two days of ordering and was well packaged. Both batteries and charger have a quality feel to them. Charging took about an hour, and after allowing them to settle for several hours the four batteries all measured 8.51v and measured equally under load, so consistency appears to be good. Having had them for less than a week, I cannot comment on their long-term performance. I am very pleased with my purchase and would definitely recommend these batteries and charger.

Charger and batteries arrived today. Very tidy and neat box. I know that sounds sad, but I like a product to be well packaged. Shows some care and thought has gone into it. Down side is they are still using a plastic tray to hold the contents. The unit itself is neat as well, big enough to do the job and yet small enough to easily fit in your pocket if you wished to. It comes with a short charging cable with a modern USB type-c end, so doesn't matter which way up it is plugged in. Small (but efficient) LEDs clearly show red for charging, or green for fully charged/empty slot. I was after some powerful, yet light 9v batteries for a Robotics project I'm working on, and hopefully with the 850mAh rating they will be a good choice. There are higher powered 9v batteries about, with some over 1000mAh, but some them are unbranded which is always a worry. If you are proud of your product, then you are happy to have your name on them. In this case, the charger and the batteries are branded. :-) The batteries weigh in at 30g each. That's about 5g lighter than the standard non rechargeable batteries I compared. Input for the charger is rated at 2.3A. Not sure if that is for all 4 batteries charging at once. This is fine with the more powerful charging circuits built for the iPhones etc, but I doubt if a pc or laptop would deliver that current. It might not work with them, or might just take longer to charge. The clear (although small printed) instructions say about 4hrs to charge. Not sure how much charge was in them on delivery, so will test that once I drain the first one. The charger allows 1,2,3 or 4 batteries to be charged at any one time. 30 day moneyback and 1 year quality gaurantee from manufacturer. Alegidly each battery can be charged up to 500 times. I look forward to happy roboting with these batteries.

Än så länge känns batterierna mycket bra. Laddaren verkar ok

Chargeur spécifique obligatoire, attention à ne pas mélanger avec d'autres batteries . Bonne durée de décharge, idéal détecteur de fumée.

True dry cell or alkaline 9V batteries start off life with more than 9V output and deliver around 9V for most of their useful life (6 cells at 1.5V), with devices cutting off somewhere about 8V. NiMH delivers 1.2V per cell so 6 cells is 7.8V for most of its capacity, and is thus likely to hit the threshold quickly. So 7 cells NiMHs at 8.4V is something of a standard and high-quality 8 cell NiMHs deliver 9.6V consistently, but the cutoff threshold tends to corresond to overdischarge for these. Thus 8.4V has become something of a defacto standard for rechargeable cell even though some devices will not work at this level. The Kratax 9V Li-Ion batteries are based around 3.7V lithium ion cells with multiplier technology to deliver around 8.75V - which means there may be (particularly older) devices they will not work in. I find their calling these 9V batteries misleading, as although they use the traditional 9V packaging they do not deliver 9V and will not work in all devices. However, the compromise of 8.7 or so (lying between 8.4 and 9V) means that fewer devices are likely to fail to work with them. Having a separate USB-C charger for four of these at once is reasonably convenient and avoids the lost capacity by building in a USB-C socket into each battery. If you previously were using NiMH batteries, this will work for you. If NiMHs didn't work and you have had to use Alkalines, these may work for you.

Très bonne qualité et performance, utilisé pour une alarme incendie. Les piles Amazon étaient vides au bout de deux semaines...à peine

Pour le moment c'est bon.