Test/review of TenaVolts AA 2775mW (Black-blue)

HKJ

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[size=+3]TenaVolts AA 2775mW (Black-blue)[/size]

DSC_9122.jpg


Official specifications:
  • Product model: NF-LB1
  • Battery size: AA
  • Charge capacity: 750mAh
  • Energy capacity: 2775mWh
  • Output voltage: 1.5V
  • Battery weight: 18g
  • Cycle times: >1000
  • Operating temp.: 32-104°F

TenaVolts%20AA%202775mW%20(Black-blue)-info.png


This is 1.5V LiIon AA batteries with build in voltage conversion for LiIon voltage to 1.5V.



I got the batteries in a nice box with specification for both the batteries and the charger.

DSC_9119.jpg


The box contained four batteries, a charger, a USB cable and a instruction sheet for the charger.

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The ring on the bottom of the cell is transparent and will emit blue light while charging, but there is only one led making the light very uneven.

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These batteries maintain 1.5V until they are empty.

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There is no significant difference in capacity at low currents, this means the self discharge is very low.

TenaVolts%20AA%202775mW%20(Black-blue)-CapacityTime.png


TenaVolts%20AA%202775mW%20(Black-blue)-CapacityTimeHours.png


TenaVolts%20AA%202775mW%20(Black-blue)-Energy.png


TenaVolts%20AA%202775mW%20%28Black-blue%29%20load%20sweep.png


The batteries do not have a hard current limit, but voltage will drop when the load is too high.

TenaVolts%20AA%202775mW%20%28Black-blue%29-Pulse-1.0A-10-10-0.7V-Pulse-1.0A-10-10-0.7V-IR.png


The internal resistance looks smooth for a electronic regulated battery.

LoadTest1A.png


The output will change little when load is applied or removed.

Spectrum1Aload.png


It looks like the buck regulator runs at about 1.4MHz. The noise is less than 30mVpp, but I cannot measure lower with the current setup.



[size=+3]Charger TS-C1[/size]

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The charger is a box with a semitransparent lid.

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Power is connected to the micro USB input.

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Behind the lightning symbol is a green led to show the charger is powered.



It has specifications on the bottom.

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The slots are standard 2 level slots for AA/AAA batteries.

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The TenaVolt are AA batteries.

TenaVolts%20TS-C1%20%28TenaVolts%29%20%231.png


The battery is charged with about 4.6V to 5V and uses an internal charge regulator, it will terminate the LiIon charge at around 50mA.

TenaVolts%20TS-C1%20%28TenaVolts%29%20%232.png

TenaVolts%20TS-C1%20%28TenaVolts%29%20%233.png

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Not much difference with the other slots (The voltage varies slightly).

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With four batteries the voltage is lower, this means slightly longer charge time.

Voltage%20sweep%20%231.png

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But what happens if a Alkaline or NiMH battery is put into the charger? It looks like it has a PTC that will limit the current. Initially it may draw all the current the USB output can deliver but after a few seconds the current will be limited. This means a NiMH will be charged continuous with around 130mA. Alkaline will be charged with higher current!


[size=+3]Charger Tear-down[/size]



I could break the charger open with a spudger.



There is two small circuit boards inside the charger and no electronic on this side.






On this side is 5 resistors and one LED, as the test shows above four of the resistors (R2..R5) are PTC's and the last resistor (R1: 10kOhm) is for the LED.





[size=+3]Conclusion[/size]

These batteries has less capacity than normal NiMH, but run at a higher voltage, making the energy about the same. This makes them ideal for most equipment that has trouble with NiMH batteries. They also weight considerable less than NiMH, this can be significant in some circumstances. There is one disadvantage: Battery meters do not work with them.
The requirement to use a special charger is a disadvantage, but if it is damaged or disappears it is possible to modify any AA USB charger for this purpose (Requires soldering skills).



[size=+3]Notes and links[/size]

Batteries and charger was supplied by TenaVolt for review.

How is the test done and how to read the charts
Compare to other AA/AAA batteries: Alkaline/NiMH/Lithium
 

HakanC

Newly Enlightened
Joined
Dec 19, 2006
Messages
97
Location
Sweden
Thankyou for the test, very interesting

Is this the most powerful 1.5V LiIon AA batteries that You have tested so far?

With a current draw of max 0,5A it can deliver more energy then the white Eneloop
TenaVolts%20AA%202775mW%20(Black-blue)-Energy.png


Eneloop%20AA%20BK-3MCCE%201900mAh%20(White)%202019-Energy.png



 

ampdude

Flashlight Enthusiast
Joined
Apr 7, 2007
Messages
4,622
Location
USA
I ran all 4 in a four AA cell incan light with a 4.8V/750mA bulb and after over and hour it showed no sign of dimming. I'm running them in a couple of specialized 2AA incan applications now.
 

Infarouge

Newly Enlightened
Joined
Oct 29, 2013
Messages
3
Great review, thanks!
Do you know if LI-ion capable chargers like the Nightcore D2 can charge LI-ion 1.5v AAs to capacity?
 

ampdude

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Apr 7, 2007
Messages
4,622
Location
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Great review, thanks!
Do you know if LI-ion capable chargers like the Nightcore D2 can charge LI-ion 1.5v AAs to capacity?

You only want to use the charger it was designed to be used with. Most li-ion chargers will try and charge the cell to 4.2V. That would be VERY VERY BAD, most likely ending in explosion with 1,000F vented flame of poisonous chemicals! Only use the charger that came with the cells.
 

HKJ

Flashaholic
Joined
Mar 26, 2008
Messages
9,715
Location
Copenhagen, Denmark
Do you know if LI-ion capable chargers like the Nightcore D2 can charge LI-ion 1.5v AAs to capacity?

It cannot, the battery has a build in charger chip and using a external LiIon charger would mean you have two chargers after each other. It would not be able to reach full voltage.
 

xxo

Flashlight Enthusiast
Joined
Apr 30, 2015
Messages
3,016
Needed to charge a couple Tenavolt cells but couldn't find my Tenavolt charger, so I tried using a SV2 Xtar charger set to .25 Amps/3.8 Volts (~4.35V output). The blue charging indicator lights on the Tenavolts lit right up and they charged no problem, might have taken a little longer, don't know as I was not keeping track of the time (thought it might take a really long time but it didn't).
 

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