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
I'm not a huge fan of those lithium ion rechargeables because of this. They make sense for certain devices that chew through 9Vs like crazy, but often, 9Vs go into things that need to last a long time. These just aren't very useful for those kinds of devices because of the self discharge issues as well as general calendar aging for lithium batteries. Unfortunately, nobody really makes good NiMH rechargeables either. The highest capacity ones on the market are about 300mah, which is only about half that of a regular alkaline battery, and the ones that are explicitly marketed as low-self-discharge are usually only around 200mah. They're fine, but the capacity is a bit disappointing considering 9V batteries have about 4.5x the volume of a standard AAA battery, and it should be possible to build a 500-600mah 7-cell 9V battery based on the volume (assuming a similar energy density as a normal low-self-discharge AAA NiMH battery).
People expect 1300ma @9v. It's probably a 1300ma cell @4v. Somebody didn't do the conversion. I really wish they would state battery capacity in watt-hours..
SOME IDEAS ON THIS... They would likely just provide the Wh for 3.6 or 3.7V, e.g. 1.3Ah x 3.6V ~4.7Wh I'd start from there, take about 15% off for conversion losses yields ~4Wh. Thus as a LOOSE APPROXIMATION for 9V constant output voltage we see... mAh=4Wh/9V~440mAh. With lower conversion losses, they might get this higher to be able to claim nearly 500mAh as a 9V output. I've seen some other true "9V" batteries claim 500mAh...so perhaps this is on the right track. Then again, I'm not feeling well and am taking some pain meds so I may be thinking unclearly. EBL has a similar "9V" battery, Model 9V600 that they claim has 5400mWh. Looking at the model number, I wonder if the "600" represents 600mAh as a 9V output (even though at 15% conversion losses it calculates to just over 500mAh). Perhaps they have a really efficient converter...along with interesting test protocols. Again, depending on their testing protocols they can move that mAh number around a LOT.
@@BeatTheBushDIYEven for large USB power banks, they always state the capacity in mAh at 3.7v, even though you can never access the energy (without disassembly) at 3.7v, only at 5v or greater. Marketing marketing marketing.
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
That's true, but it's no different from a normal battery for normal people in practice. It's only different if you're a nerd like us and go around measuring all your battery voltages with a voltmeter :)
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.
I am sure you can measure some amount of spurious noise at the output, the question is how many dBs down and how many you need for your particular amplifier to be below the noise.
I bought one of these 9V 6900mAh, I wonder what is the true mAh of it. even if I divide it with 3.7 it still doesn't sound right. what kind of scam is this? I assume they measured it with 1.5v?
AFAIK this battery would not be allowed to sell in the EU, because of intentionally misleading marking/marketing. And I noticed that it can't be found in any of the Amazon stores in the EU, so that may be why. 🙂
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
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).
Gotta put it to the test. Theoretically it's possible to put in an output circuit that can do 300mA and have a standby current around 10uA even. That would be a great 9V battery. =D
@@BeatTheBushDIY Yeah, I bought a Pale Blue "true" 9V with booster circuit, and it's useless in high current loads. I'm using it in a mini vacuum designed to trap spiders and insects, and the fan rpm is noticeably lower than with an alkaline 9V, and it also lasts for a laughably short time before needing a recharge. But at least Pale Blue doesn't appear to lie about the capacity (at least not in the same way), since it's rated for a reasonable 500 mAh. It's proven to be VERY hard to find any tests or reviews that actually test high current loads on rechargeable 9V lithium batteries (especially those having voltage booster circuits), so it would be really great if you could do it! Also, many thanks for this video, it's the most thorough examination I've found so far!
will it be safe for these types of battery to be use for a device in a car as i was thinking to get ont for my tol charging device. Sorry if i sound stupid here
Very usefull video. Could I please kindly ask you what is total weight of this battery named "9V 1300mAh" incl. skeleton? I bought from Ali "DAWEIKALA 9V 28000mAh" weighting in total 20 grams (incl. skeleton, i.e. not disassembled). Apparently the Li-ion cell itself must be there even smaller..
In the video on the Tenergy official channel, they claim to use 2 li-ion cells in their 9V battery and they say it's a nominal 7.4V, so apparently no boost converter involved.
@@BeatTheBushDIY well... they do go on to say that some devices require a higher voltage and to use their 8.4V NiMH battery in those devices - so that kind of tracks.
I meant the li-ions actually. I've found some don't keep up the full 9v or 1.5v on AA regulated properly under load and drop their voltage. An indication of the quality of the regulator circuit I guess.
4.837 wh Battery Output: "kwh or wh is correct power rating" (E x I = P) 9v (E) x 1.3 x 3.7 / 9 (I) = cancel the 9s and 1.3 x 3.7 = 4.837 wh (P) The electronic ckt onboard will maintain the 9v constant. The labe states 9v x 1.3ah false rating of 11.7 watts per hour. Note the battery of 3.7v @ 1.200 wh is the factor only, voltage is only the product of that with a loss. So fully charged is a joke due to 4.3 to 4.15 is minutes apart on any lipo or lion battery test if you ever did many tests I have. 550 alkaline to lion is okay. Maximum amperage rating should be included in sale. "9v 4.837wh 1.5amp(max amperage)" the output IC limits amperage usually by it's thermal internal ckt.
You be way better off to get a 9-volt battery holder that holds two double a batteries and put in the lithium 14500 battery cell those batteries are about 1,000 Ma and your project will last a lot longer
@@BeatTheBushDIY not in that circuit that you're taking apart my friend you charges batteries up in a regular lithium charger and then their balance then you put them in the battery holder and it put that into your project now you have 8.4 volt battery
Better off using a DC load and actually measuring at the 9V output. Then you'll get a real reading. Your maths doesn't include the efficiency of the boost converter which is not going to be anywhere near 100%.
@@BeatTheBushDIY perhaps the rating was affected by continuous operation? Did the temperature of the battery increase and possibly affect the output? Probably wouldn’t make enough of a difference at this scale although who knows I haven’t tested it myself. Just buy another battery and call it a day 😁
@@theChef1337 The 100mA draw probably reduced the capacity and I might see 1350mAh if drawn at say 25mA. However, the 1350mAh is for the 3.7V and not 9V.
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
Agreed.
True. But at least ZNTER and Etinesan both show their battery capacity using both units.
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
You should take in account the consumption in the converter circuit.
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.
I knew that the top MAH is not really so. But it still works.
nice video thank you
I'm not a huge fan of those lithium ion rechargeables because of this. They make sense for certain devices that chew through 9Vs like crazy, but often, 9Vs go into things that need to last a long time. These just aren't very useful for those kinds of devices because of the self discharge issues as well as general calendar aging for lithium batteries.
Unfortunately, nobody really makes good NiMH rechargeables either. The highest capacity ones on the market are about 300mah, which is only about half that of a regular alkaline battery, and the ones that are explicitly marketed as low-self-discharge are usually only around 200mah. They're fine, but the capacity is a bit disappointing considering 9V batteries have about 4.5x the volume of a standard AAA battery, and it should be possible to build a 500-600mah 7-cell 9V battery based on the volume (assuming a similar energy density as a normal low-self-discharge AAA NiMH battery).
I have the TQTHL variants of this battery - same thing, of course.
2:48 your image shows: 1300mAh / 0,137mA . Should be 1300mAh / 0,137 A. Then you get 9,489 hours, wich is a much more realistic operating time.
That's just standby time on its own. It's not that bad.
People expect 1300ma @9v. It's probably a 1300ma cell @4v. Somebody didn't do the conversion. I really wish they would state battery capacity in watt-hours..
SOME IDEAS ON THIS...
They would likely just provide the Wh for 3.6 or 3.7V,
e.g. 1.3Ah x 3.6V ~4.7Wh
I'd start from there, take about 15% off for conversion losses yields ~4Wh.
Thus as a LOOSE APPROXIMATION for 9V constant output voltage we see...
mAh=4Wh/9V~440mAh. With lower conversion losses, they might get this higher to be able to claim nearly 500mAh as a 9V output. I've seen some other true "9V" batteries claim 500mAh...so perhaps this is on the right track.
Then again, I'm not feeling well and am taking some pain meds so I may be thinking unclearly.
EBL has a similar "9V" battery, Model 9V600 that they claim has 5400mWh.
Looking at the model number, I wonder if the "600" represents 600mAh as a 9V output (even though at 15% conversion losses it calculates to just over 500mAh). Perhaps they have a really efficient converter...along with interesting test protocols.
Again, depending on their testing protocols they can move that mAh number around a LOT.
At least for larger batteries they state the Wh. For these tiny ones, seems like there are not regulations.
@@BeatTheBushDIYEven for large USB power banks, they always state the capacity in mAh at 3.7v, even though you can never access the energy (without disassembly) at 3.7v, only at 5v or greater.
Marketing marketing marketing.
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
GOOD POINT! VERY good point. They almost need a warning on these 9V batteries for that.
That's true, but it's no different from a normal battery for normal people in practice.
It's only different if you're a nerd like us and go around measuring all your battery voltages with a voltmeter :)
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.
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
I am sure you can measure some amount of spurious noise at the output, the question is how many dBs down and how many you need for your particular amplifier to be below the noise.
I tested the same from and other supplier and also came out at about 400mAh @ 9V
I bought one of these 9V 6900mAh, I wonder what is the true mAh of it. even if I divide it with 3.7 it still doesn't sound right. what kind of scam is this? I assume they measured it with 1.5v?
Very nice ! Please please a new video with this time good surprises and great 9v rechargeable you could then advise.
I don't understand.
AFAIK this battery would not be allowed to sell in the EU, because of intentionally misleading marking/marketing. And I noticed that it can't be found in any of the Amazon stores in the EU, so that may be why. 🙂
Buyer beware!
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
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).
Gotta put it to the test. Theoretically it's possible to put in an output circuit that can do 300mA and have a standby current around 10uA even. That would be a great 9V battery. =D
@@BeatTheBushDIY Yeah, I bought a Pale Blue "true" 9V with booster circuit, and it's useless in high current loads. I'm using it in a mini vacuum designed to trap spiders and insects, and the fan rpm is noticeably lower than with an alkaline 9V, and it also lasts for a laughably short time before needing a recharge. But at least Pale Blue doesn't appear to lie about the capacity (at least not in the same way), since it's rated for a reasonable 500 mAh.
It's proven to be VERY hard to find any tests or reviews that actually test high current loads on rechargeable 9V lithium batteries (especially those having voltage booster circuits), so it would be really great if you could do it!
Also, many thanks for this video, it's the most thorough examination I've found so far!
which one would be the best to buy
will it be safe for these types of battery to be use for a device in a car as i was thinking to get ont for my tol charging device. Sorry if i sound stupid here
I doubt they test these in extreme temperatures.
Is that battery several times better than a 250 rated version?
Very usefull video. Could I please kindly ask you what is total weight of this battery named "9V 1300mAh" incl. skeleton? I bought from Ali "DAWEIKALA 9V 28000mAh" weighting in total 20 grams (incl. skeleton, i.e. not disassembled). Apparently the Li-ion cell itself must be there even smaller..
This one is 27g for the entire battery with the plastic case. Hope that helps.
In the video on the Tenergy official channel, they claim to use 2 li-ion cells in their 9V battery and they say it's a nominal 7.4V, so apparently no boost converter involved.
No way they can output 7.4V in a 9V battery. It just wont work! I think when they say nominal, it means 'the batteries inside nominally is" 7.4V.
@@BeatTheBushDIY well... they do go on to say that some devices require a higher voltage and to use their 8.4V NiMH battery in those devices - so that kind of tracks.
Wait till you discover the fake Ernie Ball Chinese strings
great video, thanks for writing out the math, keep them coming !
Thank you!
Any chance of seeing the 9v output voltage sag, if any, under load?
Alkaline 9V sag a lot but I usually use these in low current products so didn't think about high loads.
I meant the li-ions actually. I've found some don't keep up the full 9v or 1.5v on AA regulated properly under load and drop their voltage. An indication of the quality of the regulator circuit I guess.
Good point. I think most times they don't design them for high drain situations. Works well for low drain stuff.
4.837 wh Battery Output: "kwh or wh is correct power rating" (E x I = P) 9v (E) x 1.3 x 3.7 / 9 (I) = cancel the 9s and 1.3 x 3.7 = 4.837 wh (P) The electronic ckt onboard will maintain the 9v constant. The labe states 9v x 1.3ah false rating of 11.7 watts per hour. Note the battery of 3.7v @ 1.200 wh is the factor only, voltage is only the product of that with a loss. So fully charged is a joke due to 4.3 to 4.15 is minutes apart on any lipo or lion battery test if you ever did many tests I have. 550 alkaline to lion is okay. Maximum amperage rating should be included in sale. "9v 4.837wh 1.5amp(max amperage)" the output IC limits amperage usually by it's thermal internal ckt.
You be way better off to get a 9-volt battery holder that holds two double a batteries and put in the lithium 14500 battery cell those batteries are about 1,000 Ma and your project will last a lot longer
The way you suggest might result in over discharging as there's no cell over discharge protection.
@@BeatTheBushDIY not in that circuit that you're taking apart my friend you charges batteries up in a regular lithium charger and then their balance then you put them in the battery holder and it put that into your project now you have 8.4 volt battery
If im not wrong, that aint an ion, its a li polymer
Better off using a DC load and actually measuring at the 9V output. Then you'll get a real reading.
Your maths doesn't include the efficiency of the boost converter which is not going to be anywhere near 100%.
So we are not so advanced in battery technology after all lol
4.15 is not fully charged so your test is not good, bring it to 4.2 and do it again
It is charged to full with the internal charger already. No one will disassemble it to do this in typical usage scenario.
4.15 volts is about 95% full for lithium-ion batteries.
at least it doent look LIPO !!
What's wrong with lipo batteries?
@KaMyKaZii not much if they build them great , but the great ones are getting harder ,and less likely to be a OEM . Just like lots of things lately
Rechargeable batteries: EXPOSED
I'm a bit miffed.
@@BeatTheBushDIY perhaps the rating was affected by continuous operation? Did the temperature of the battery increase and possibly affect the output? Probably wouldn’t make enough of a difference at this scale although who knows I haven’t tested it myself. Just buy another battery and call it a day 😁
@@theChef1337 The 100mA draw probably reduced the capacity and I might see 1350mAh if drawn at say 25mA. However, the 1350mAh is for the 3.7V and not 9V.
Don’t say amperage. Say current.
Why?
@Derpy1969 see a doctor.