They Lied about their 9V Battery Capacity

What is inside a 9V rechargeable li-ion battery? Some batteries claim 1300mAh but what does this mean? One would expect it to output 1300mA for one hour but this is not the case. Instead, it is referring to the output capacity of the internal li-ion battery, pretty useless for showing the capacity of the 9V battery itself. Still, it is a rechargeable battery and can help you buy less alkaline batteries. Check out the video so see the insides of this device and various measurement methods I used to arrive at these conclusions.

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[noctambulomissthesun]

thanks for the info
You should make a new video with the current 9v batteries to know how much you get from a 600mah batt

[JaayTea]

I'm honestly surprised it's only a little bit off from what was advertised, I was expecting 1/4 of the advertised capacity at most

[bretep]

Thank you that explanation was very clear and informative, I am about to buy a couple of these so now I know what to expect from them.

[volodumurkalunyak]

0:28 - yes, you can
1. So called "1.5V" alkalines arent 1.5V, those have 1.6V fully charged, 1.3V mid-piloint and 0.9-1.1V almost empty.
2. Li-ion "3.7"V is full at 4.2V, has mid point at 3.7V and almost empty at 3.2-3.3V.
2 of Li-ion fit in perfectly in 6×Alkaline 9.6V - 6.6V range. Even battery level indicator will work almost fine (except it will maybe have 70-80% on 100% charged 2S Li-ion and rest of the readings scaled proportionally).
I have those packs so I do really know - those do really work and yes, they work fine.

[maquinas-texiles-peru]

great review 🎉

now i think is best the old step up dc/dc module with a old cellphone battery 😅

[killer]

They didn't really lie, they just catered to a typical person's misconception. The capacity (should) always refer to the battery capacity BUT this 9v battery ISN'T a "battery" but rather a "power bank" that outputs 9v. Akin to the portable power banks we use to charge our smart devices on the go. With those devices that output 5v via USB, we don't use 5v when we do mAh to watt-hour calculations but instead we use the 3.7v (nominal) of the actual Li-Ion battery itself that is inside of "power bank".

[prooffypro]

You should take in account the consumption in the converter circuit.

[Mulakulu]

mAh is a stupid unit to measure battery capacity. We should use Wh or just J, since then you don't need to know what voltage is being used to know how much energy is actually stored

[RaptorRotorHead]

Wait till you discover the fake Ernie Ball Chinese strings

[HasanSaclay]

Nice vid . I was wondering about the output noise and whether this kind of battery suitable to use with amplifier

As it contains a boost converter

[williammchugh]

I have another brand that I use with a similar charger with alligator clips. These do not have a usb port. These do not advertise that they are True 9 volt. The voltage is max 8.4. I assume these are just 2 cell batteries which operated at a lower voltage. I set the charger to 2 cell, and charge them to only around 8.1 volts. The lower voltage doesn't seem to matter to my smoke detectors.

I'm surprised you could even charge these batteries with alligator clips if the power coming out is running through a boost circuit! Perhaps you meant you charged around the USB connector.

I like these other type so far and do a top off charge about every 3 months, the batteries in the smoke detectors are barely drained and only require maybe 20 mah each to top (and the capacity of these batteries is like 500+ mah).

Thanks for letting me know that these true 9 volt batteries are not the way to go UNLESS your device is unhappy with top voltage under 9 volts. Incidentally, while it sounds like a ripoff that they advertise "deceptive" capacity based on true battery voltage, the manufacturers of USB Power Banks often do the same thing. That's why people complain about true use capacity vs advertised capacity of these power banks. They're advertising the capacity of the cells Before the voltage gets boosted.

[fredvankempen]

I have the TQTHL variants of this battery - same thing, of course.

[exgenica]

Some of these "true" 9V batteries with booster circuits do not like high current loads (like 1A). I've seen a couple that claimed a limit of something like 300mA if I recall correctly...which is still pretty hefty for typical uses of a 9V battery in this small "6LR61" form factor.

I've also seen a number of these batteries CLAIM they retain 75%-80% of their stored capacity after a year on the shelf. So their circuits must consume considerably less than 100uA when not connected to anything external (or they are lying, or using some non-standard testing protocols to bump up that percentage).

[vevenaneathna]

ugh i hate these. the buck converter makes a 50 hertz garbage buzz that gets really bad at higher current draws so its useless for audio equipment/microphones. I also believe the poorly tuned oscilator voltage step thing messes with smoke detectors and even though it has capacity it will randomly wake u up at 2am with a fire alarm/low bat chirp.
also, i presume because of how poorly tuned that buck converter is, it has a lot of loss of something like 15%. i dont think anyone has put one of these on a oscillaskope yet but im guessing it will look like a guangzhou sawtooth electrical grid frequency mismatch at 6pm on a monday

[victorpiedra]

It looks pretty good, but that type of batteries with a voltage booster circuit cannot be monitored on the device in use to indicate the charge level or when it is getting low, that is, you cannot see at what point the charge of the battery 🔋 is, but at a certain point without prior notice the device will turn off when the battery charge has dropped to the point where the internal electronics cut off the operation of the internal voltage booster, for a toy or a device such as a multimeter yes I would use it, but not on something critical like a fire alarm or smoke detector

[philgibe]

Very nice ! Please please a new video with this time good surprises and great 9v rechargeable you could then advise.

[glbernini]

Is that battery several times better than a 250 rated version?

[eddiejr]

great video, thanks for writing out the math, keep them coming !

[makestuffwork]

Any chance of seeing the 9v output voltage sag, if any, under load?

[bretthermance]

I knew that the top MAH is not really so. But it still works.