9V Rechargeable Battery,850mAh High Capacity Li-ion 9V Batteries 4 Pack PP3 6F22 9V E-block Lithium Batteries for Smoke Detector Alarm,Fire Alarm,Multi-meter,Radio Microphone,Kids Toys(Battery Only)

I was looking for some 9v lithium rechargeable for smoke-alarms, water leakage alarm, gadgets, etc. I have already some in use, but as the number of gadgets using PP3 increased, I didn't want to use single-use alkaline or lithiums. As a matter of fact, I had bought some 9v "industrial grade" alkaline of a well-known brand but was disappointed by the performance. I was about to order more of a brand I had been using till I came across these Kratax at 850mAH. Naturally, at 850mAH, they are a bit more expensive. Was it worth paying the extra? I decided to take the plunge because I am an Eneloop battery user, and believe me, you pay a premium for quality., but it's worth it in the long run. The Kratax batteries arrived in a study box (I opted for 4 pieces). I immediately put them on to charge. I wanted to see how well they could keep the charge and if the voltage would be up to a level acceptable to run most 9v gadgets. As you may know, most rechargeable PP3 are rated at most 8.2-8.5v, and because of this, are not recommended for alarms. I was glad to see that these charged to over 8.6v which was better than the 8.3 I got from my old PP3s of a different brand. After over a week on the shelf, I checked and was pleased to find that the voltage remained at over 8.6v+ and had hardly dropped. I'm sure with a few more charging cycles, the voltage will creep even nearer the 9v mark. There are admittedly early days, but the signs are very good. They have gone into some gadgets and not a beep from under-voltage. Like my Eneloops, these are worth the little extra.

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.

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.