9V 800mAh Rechargeable Batteries and Charger, Keenstone 9V PP3 Lithium-ion Batteries, Low Self-Discharge High-Energy-Density Batteries with 500 times (3 Pack)

There are two distinct types of 9v (PP3 package) rechargeable Lithium-ion batteries available. One has a single cell with a tiny circuit board that controls the charging of the cell from a USB connection. This type has a DC to DC converter within which will maintain a constant output voltage until the internal cell is depleted enough to cause the control board to switch off the converter output. They usually have an constant output of 9.0v. The second type contains two cells, giving an output of around 8.6, depleting lower than 6.0v as it is discharged. This type usually has an external charger. It has two cells internally with a (claimed) small circuit board that controls the charge and discharge. This type's output voltage falls as the cells are depleted, down to levels that are similar to an alkaline battery when depleted. These batteries are of the second type. I have many lithium batteries and the necessary devices needed to manage them, including testing. One battery went directly into one of my IR detectors that usually needs charging every three weeks on a NiMh battery. It will take time to see how that works. The other two batteries were charged and discharged a couple of times, fully charged and then discharged in a controlled and measured test to check for output voltage and capacity. They both discharged at around 60mA for several hours until their output voltage dropped to 6.6v (corresponding to 1.1v/cell in an NiMh battery of 6 cells). One discharged 784mAh and the other a little more. The discharge went down to around 10% of the capacity of the battery (you can never fully discharge them without risking some damage), so the actual capacity was around 870 mAh and the actual used capacity nearly 800mAh. This is very impressive as the nominal capacity will be degraded at higher discharge rates. At the low rate that you might find on an alarm or electron meter, the capacity will be higher. One charged battery was discharged at 500mA for 20min without getting warm or dropping its output voltage dramatically. These are very good batteries. I can't test their life span or their ultra low self discharge as that takes time. I also didn't try to verify that the internal control board would protect the battery in the event of a short circuit, over discharge or overcharge voltage as those can destroy the battery. The usable capacity that can be drawn from them is largely down the the equipment that it is used in. That will be preset to treat the battery as flat at a given voltage and give the usual indications etc (something that probably would not happen at all with a battery of the first type. This is the type that should be used in a smoke alarm if a change to lithium batteries is being considered as it will give a similar low battery chirp to alkaline batts before failing. Good batteries, recommended.

I use these for guitar pedals and they last a lot longer than other 9v batteries I've l used. Highly recommend

Good product, but naturally the connectors on 9v batteries are not typically very sturdy which shortens the lifespan. Good product overall however

I use 9v batteries all the time. Recharging has been perfect instead of buying new ones. Power last noticeably longer than normal 9vs.

I have a guitar that eats batteries; if I'm lucky, a 9v battery at £3 a pop will, and my guitar requires two, give three or four days of use. I had tried using rechargeable in the past, but they simply could not cut it. This has meant that my guitar tended to spend a lot of time in its case than I would have liked...until now; when somebody suggested I try these. I stared with just the three to see how it went. After nearly two weeks of playing, heavier than usual too, the batteries finally showed signs of needing a charge. Not only were they lasting close on four times as long; by my reckoning, they will have paid for themselves within a month! I have now purchased a second set...and my treasured Schecter is now permanently out of its case!!! Awesome stuff...

Good

Decent batteries with a lot of power. Only frustration is that they can only be charged with the supplied charger.

Like many of the reviews, I bought this for a guitar that takes 2 9V batteries for active electronics and an old silicon fuzz that takes a battery. Works brilliantly first time, no noise or interference, and the set comes with 3 batteries so you'll always have a spare one fully charged. They charge to full in a few hours, yet to determine the life, but given you'll be saving yourself £3-5 per battery they'll easily cover the costs back.One thing to be aware they are slightly larger than a standard 9V, so if it's a snug fit you're using them for, particularly in pedals, be aware before you buy.

Pas de soucis pour le moment

Utilisée pour des détecteurs de fumée, rien à dire pour le moment

le sto usando per i pedalini da chitarra elettrica, ottime, gia fatto tre cicli, funzionano bene, in particolare segnalo il risultato soddisfacente su un pedalino reverbero della behringer che a pila era inusabile!si mangiava una pila alcalina 9V in un ora! con queste si fa almeno 4 ore abbondanti. gli altri pedalini classici boss si va tranquillamente a 8 ore di funzionamento se non di più

van super bien, y duran mucho su carga, yo las utilizo para micrófonos inalámbricos 4 veces por semana y dos horas consumiendo y me duran 3 semanas hasta volver a cargarlas. las descarga del todo y las carga completas, no me han fallado ninguna, solo hecho de menos que sean 4 unidades por que yo cambio de dos en dos

Jag är väl förtrogen med Lithium/Jon-celler då jag har använt dem för hobbyändamål i många år.Batterierna mätte ca 7,6 V vid mottagandet. Det motsvarar 3,8 V per cell och är den rekommenderade polspänningen vid långtidsförvaring..Full uppladdning tog mindre än en timme. Ett batteri monterades i en Shure Beta 58 trådlös handmikrofon och systemet med mottagare kopplades på.8 timmar senare fungerar fortfarande allt som det ska. Batteriindikatorn visar två av tre staplar möjliga. Jag är nöjd med resultatet och stänger av.Min enda anmärkning är att produkten marknadsförs som ett 9 V batteri. Två fulladdade seriekopplade lithiumceller har polspänningen 8,4 V. Allt över det tyder på överladdning.