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This means that for $22.79 plus sales tax each battery costs about $2.42 each including 6% sales tax. Short and Sweet Findings: 1. These batteries are only about half as good as they claim, so about 950 mWh not the 1900 mWh they claim. (mWh = milliwatt hour, mAh = milliamp hour) 2. These batteries can't be used in an AM/FM radio because, I assume, the RF (Radio Frequency) noise of the voltage converter circuit (to change the 3.7 volts of a Li battery to the 1.5 Volts of an AA battery) blanks out all radio stations unless they are very strong. (Note: Li AA Energizer batteries, not rechargeable, do NOT cause any problems in the AM/FM/Weather radio that I tested these batteries in.) 3. These batteries can't be used in a Ham Radio HT because of 2 problems, a: Same as above in #2 b: These batteries also blocked a Baofeng HT from transmitting or receiving on 2 meters simplex. Bottom line: They can be used in things like flashlights and remote controls. But NOT in any kind of AM/FM or Ham 2 meter radio, and also for not as long as they claim. Note: I don't yet know if the interference from these batteries is in the Intermediate frequency used to beat with the AM or FM RF signal when trying to decode the signals, or it interferes with the actual RF frequencies being received. I only found one spike at around 1.4 MHz using my SDR Ham Receiver. For more information see: Intermediate frequency, Wikipedia Last: As mentioned above in #3: In addition I tested these in a Ham Radio VHF/UHF hand-held radio to see if I could receive anything. I could not receive a local repeater, 15 miles away. I also tried to transmit on 146.520 simplex to another radio in the same room and it did not transmit, at least NOT at 146.520 simplex. Using the NiMH battery pack, or the radio's battery pack the radio was able to hear the repeater and it was able to transmit as well. In-Depth Explanation: - Going back to the beginning... The first thing I noticed was that these are rated in mWh not the normal mAh of the NiMH AA rechargeable batteries I normally buy. In order to convert mWh to mAh we have to divide by the voltage; in this case they claim 1.5 Volts so 1900 mWh/1.5V = 1267 mAh. (W = V*I) The problem with this type of rating (mWh) is that it depends on the voltage. Normally for batteries the voltage decreases until the battery is considered dead or depleted. Using the mAh rating only depends on the amps being used, and my CBA (Computer Battery Analyzer) software can set the current (mA) to a constant rate, independent of the voltage. I selected 200 mA for all of these tests. This is why most NiMH and other batteries we buy are rated in mAh and NOT in mWh. I admit, I don't know why they decided to use mWh but I can think of two possibilities, 1. They are trying to fool people who don't know the difference between mAh and mWh. 2. It is assumed that all the batteries' output voltages are 1.50 V so using mWh is as valid as mA. However, I found that this is not valid because of the 10 batteries I tested most were running at 1.44V after the initial settling time but the range varied from 1.40 to 1.48V. None of the batteries actually ran at 1.50 V for more than a few seconds before the battery settled to its running voltage. Let me quickly say that I'm a ham radio operator and an Engineering Physicist. I have worked for two companies measuring, testing, and selecting rechargeable batteries for the products we were manufacturing, as well as selecting batteries for my ham radio hobby. I tested all 10 batteries because when I tried to use them in a simple home-built LED Dead-battery night light, two of these didn't even last through two full nights of about eight hours. Why was this, when "dead" Alkaline batteries (measuring 1.00 Volts) will last for weeks and my fully charged NiMH battery (rated at 1900 mAh) lasted a full 7 nights and was still measuring 1.23 Volts? (Measured while in the LED night light while it was turned on.) To get a good idea of exactly what these batteries can do, I use my CBA-IV Computer Battery Analyzer (CBA) version 4 (IV) and I decided to run them at 200mA. For a battery claiming 1900 mWh or about 1267 mAh they should last about 1267mAh/200mA ~ 6.34 hrs. This tester is available at West Mountain Radio (though they are now selling the CBA V). As expected from my crude dead-battery LED night light tests, none of the batteries even came close to that. The worst measured 34.0% mAh of the 1267 mAh and the best made it to 47.99% of the 1267 mAh calculated rating. The mWh ratings were a bit better, the worst was 44.4% and the best was 60.9%. This is probably why they prefer to give their ratings in mWh instead of mAh, the rating used on all NiMH batteries I've seen. None of the batteries remained at 1.50 Volts but they all maintained a voltage of between 1.40V to 1.48V, with most coming in at 1.44V. A Lithium battery measures about 4.2 Volts after being charged. In operation it will decrease quickly to about 3.7 V and then the voltage decreases more slowly to the cut-off voltage of about 2.8 Volts. I don't know what their battery protection circuit cut-off voltage is. So how do they get a Li battery to be 1.5 Volts? They have to use a circuit that cuts the voltage and tries to maintain a voltage of 1.5 V but the circuits obviously vary quite a bit because the 10 cells I have ranged from 1.40 to 1.48 running voltage for the majority of time of the tests and none of them remained at 1.50V for more than a few seconds. I'm assuming that a switching circuit is used to maintain the running voltage. The thing about switching circuits, which can do this kind of voltage changing, is that they can be very RF noisy. (They will create radio frequency noise.) Being so small they probably won't interfere with anything more than a few feet away, but if you use these you do need to know about of the possible/probable RF interference. As stated in the quick review, I tested these cells in a hand-held AM/FM/WB radio and all I heard most of the time was static on all three bands, AM, FM and WB (weather Band from NOAA). Replacing these batteries with my standard NiMH (Nickel Metal-Hydride) rechargeable batteries, the radio was able to bring in DC, Frederick, Baltimore, and Washing DC AM, FM, and WB stations clearly (20-30 miles away). The results of using these batteries in a ham radio walkie-talkie (HT) was even worse. Not only couldn't the HT receive a signal from a repeater only 15 miles away, but it couldn't even transmit to a radio only ten feet away. So, these cells are only about half as powerful as they claim, they are RF noisy, and I definitely do not recommended them for use in portable battery-operated radios. So where can they be used, even if they don't last as long as the seller and/or the manufacturer claims? I'd say in LED flashlights and in remote controls which use AA batteries. As long as the shelf life hold up to that of most Li type batteries this should be a good fit. These batteries claim to have a shelf life of 20 years, and I assume that means about 75% of full charge after 20 years. I have no way of actually testing for shelf life other than charging them, putting them on a shelf for at least a year, then measuring the mAh and mWh in another test, and then extrapolating to the time it will take them to degrade to about 75% of the full charge values. Nothing about shelf life can be inferred from the tests I've already done. the min, #01, the max #05, and and approximate average #02 and 03: The green line is #04 just beyond 02 and 03 which are approximately the average. |
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Note: These batteries are nowhere near
their claimed mWh rating for brand-new, off-the-shelf batteries.
Batt # Whr Ahr Test I mA End V Run V T min % Whr % Ahr |
| 01 0.843 0.576 200 mA 1.05 1.48 172.50 44.37 - 45.47 |
| 02 1.009 0.709 200 mA 1.05 1.43 212.40 53.10 - 55.97 |
| 03 0.985 0.699 200 mA 1.05 1.40 209.37 51.84 - 55.18 |
| 04 1.036 0.728 200 mA 1.05 1.43 218.10 54.53 - 57.47 |
| 05 1.158 0.800 200 mA 1.05 1.45 240.11 60.95 - 63.16 |
| 06 1.061 0.736 200 mA 1.05 1.44 220.59 55.84 - 58.11 |
| 07 1.053 0.722 200 mA 1.05 1.43 216.36 55.42 - 57.00 |
| 08 0.930 0.650 200 mA 1.05 1.43 195.04 48.95 - 51.32 |
| 09 1.093 0.754 200 mA 1.05 1.45 226.12 57.52 - 59.53 |
| 10 0.969 0.666 200 mA 1.05 1.46 199.56 51.00 - 51.58 |
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| Totals: |
| Avgs: 1.014 0.704 53.35 - 55.48 |
| Lowest: 0.843 0.576 44.37 - 45.47 |
| Highest: 1.158 0.800 60.95 - 63.16 |
Phil Karras / KE3FL -