#45 - 9V Li-ion batteries: capacity testing 

Thanks for the info.

Cool. Thanks for sharing the info.

Thanks for sharing 👍

I don't think that 1200mAh rechargeable li-ion is realistic in this physical package. I would expect around 600-800mAh. You probably saw non-rechargeable lithium batteries.

No, I have not tried such batteries yet. How did you measure?

FeedbackLoop Hi, I used an inline capacity meter and got consistent results with 3 different batteries. When charging from flat, the batteries absorbed around 750 mA Hrs, so they were never going to give full capacity, but 15% capacity was hugely disappointing. I will try testing one with my imax B6, just to see if it gives similar results.Cheers, Colin

It has been a while. They are all over eBay. Watch out: there are Ni-MH ones (280mAh) that look very similar to Li-ion.

+T Komoski The approach was like this: set the voltage target at 8.4V, set the current limit at 0.2C, come back in many hours (in the morning), start discharge test on this battery, hook up another one, come back in many hours (after work), repeat.

No, I have not tested such batteries. I agree that probably many of the no-name cheap ones are of poor quality.

Thanks for getting back so quickly. Kind of what I figured about the off brands. The name brands are just so expensive. BTW, your video on spectrum analyzer is great. Luckily, mine is still working.

No, we will just let him monetise and keep him for ourselves 👍👍

qwaqwa1960 fake batteries ratings are so common. It's safe to assume the 900mah batts are total frauds. Also, the highest capacity batteries are new models from big manufacturers so the fact that this is a no name manufacturer is just more evidence

He said there are 2 cells (3.7 VDC), giving an output voltage of 7.4 VDC.

I have not looked at new batteries. Lifepo4 cells have lower voltage: about 3.2V nominal and 3.6V max charging. So with 3 cells (not 2 as in Li-poly) that would be 9.6V nominal and 10.8V max charging. Yes, that might work better with some equipment. I need to look at that some day. Thanks.

@@feedback-loop i hope in the future someone is building a pp3(9v block battery) with lifepo4 technology :-)

What is pp3?

@@feedback-loop hi, that's the size format of the 9v batterys like on typ aa(Mignon, sp7, hp7) and aaa (Micro, R03, 24, UM4) for the smaller round cells is the form factor PP3 for the 9v block Battery's ;-) you can find it ever buy putting in the search bar PP3 :-) en.wikipedia.org/wiki/Nine-volt_battery

I thought this format is 6F22

I do not know for sure. Perhaps it does not like lower voltage. As I explained in the video, rechargeable lithium ion batteries are not really 9V, but 7.4V nominal, 8.4V when fully charged, and about 6V fully discharged. There should be no harm in trying except potentially wasting money on a rechargeable battery just to find that the safe indeed does not work with it very well or at all.

@@feedback-loop That was my thoughts, Im thinkin the safe might show battery as low even when rechargeable battery is fully charged. I may have to install a different digital keypad that takes AA or AAA batteries if I can find one

I suffer same with my safe Jay. Fresh top shelf batts die fast to pull the latch so I too am looking for a rechargeable solution to allow me to leave 2 in the keypad and 2 on a charger so i can always be sure to be able to open it but I may need to build instead some sort of plug in power source with an ugly surface wire

@@Method_MOKLike I said This would be a non issue if it used AA/AAA batterries as I have some of the best rechargeables (Panasonic/Sanyo Eneloops) and even Alkaline AA/AAA's are cheaper than 9v & last longer

I opened that failed 700mAh battery and found 600mAh cells inside. Sorry, I did not record the teardown.

Of course, NiMH chargers won't do. Plenty of Li-ion chargers for these batteries are sold everywhere.

FeedbackLoop I see, I was not aware of this type of battery. Great video, as always

I did not test those USB-C batteries. I am a bit skeptical about the whole idea. The batteries I tested have two Li-ion cells and no converter. This means 8.4V fully charged and about 6V fully discharged. Perhaps the equipment will cut off before battery reaches 6V. The USB-C ones have one cell (4.2V charged, 3V discarged, but that is internal and irrelevant) and converter to a steady 9V. Advantages: not sure if USB-C charging is an advantage, but a bit easier than a dedicated charger. Steady 9V - full capacity available (sort of). Disadvantages: USB-C connector and converter take space, which could be used by larger cells. Converter is not 100% efficient (perhaps by far), therefore some losses. And in any case the Shure equipment will be confused, and the battery indicator will be of limited use. Perhaps worse with steady 9V. It will show full until it dies. I used the batteries I showed in the video with Shure ULX transmitters, and I am quite happy with that. The battery indicator is not entirely useless.

@@feedback-loop The battery indicator being useless was the issue that I found with the two brands of USB-C 9 V that I had tried in the ULX handhelds - one brand indicated 1 bar until completely discharged while the other showed full charge until the very end. Both had considerable use time before dying, but the battery meter inaccuracy makes me hesitant to use them since multiple operators of varying levels of diligence would be using them. The ones that you are using seem to be a good option I think I might give them a try.

Hm... Li-ion EBL batteries? Mine work fine for 6 years since this video was made. And I think it is not quite fair to include the cost of the charger into this comparison.

@@feedback-loop You can't use the cells if you can't charge them, and the charger came with the set of 4 cells. So I think it is a fair comparison. If I don't include the cost of the charger, then the comparison is even worse. At least I still have a working charger that is worthless if I don't purchase more of the EBL batteries. Why would I purchase more of these when alkaline batteries cost less to use and don't drain themselves dead.

That is a good idea to measure the noise and oscilloscope.

Саша Иванов Two 400mAh in series only provides 400mAh (at double the usual 4V, so 400mAh at 8V). I think all the Lithium "9V" bats are two cells in series. Better ones include electronics that ensure they are charged the same and not differently. And of cause the cells may be 300mAh up to a little over 600mAh each.

Do you think discharging with 120mA instead of 180mA will make a significant difference? I don't think so. By the way, I did take apart that failed 700mAh one. The cells are marked 600mAH :) One of the cells failed.

Of course they are 8.4V by design. You seem to be quite sure that they don't work well, right? How did you reach this conclusion?

With a volt meter. The "9 volt" lithiums are only 7.4V @@feedback-loop

@@Airsails so? they are roughly from 6 (discharged) to 8.4 volts (fully charged) as opposed to roughly 6 to 9 volts alkaline. I would think most products designed to work down to about 6 volts. did you actually try or you just speculate?

My TENS unit and variometer go dead very quickly with the reduced voltage. I found that the EBL 280mAh NiMh is best as it can be charged to over 9V.@@feedback-loop

Some sellers send the batteries inside a flashlight or other cheap item to avoid that problem.

no

+FeedbackLoop :( Жаль

+FeedbackLoop придется учить английский