This test instrument was specifically designed to measure the power consumed by battery operated devices, like cell phones, and to measure the associated battery and battery charger.
|1.5v 1 ma
N 50 ma
& C & D 150 ma
AAA, C, D, N
U.S. Patent 6823274 shows on the front panel.
|3.6 V Lithium-Ion
|1.5V Button Cell
|1.2 V NiMH
|1.5 V AA Lithium
|3V Lithium Button
|6 V 28 Series
|1.5 V Alkaline
|12 V Alkaline
|9 Volt Alkaline
Drop TestThe idea is to drop a AA battery with the + end up on a reasonable hard surface.
This may work for other Alkaline cells?
A good battery will make a thud sound, no bounces and may stand up.
A bad battery will sound metallic, bounce and fall over.
How To Test a AA battery, Easiest Way For Any Battery Fast, Easy!
The comment about testing with a volt meter is wrong. A no load test does not mean anything.
For a meter test to mean something the battery needs to be loaded. See the TS-183. Even load testing does not work well on modern batteries.
By measuring the current and the elapsed time the product of
them is how many coulombs (Wiki) have
flowed. Most modern rechargeable batteries use coulomb
counting to determine State of Charge and that can be translated
into remaining run time.
This is a stand alone coulomb counting circuit available on
with a title of "Capacity Tester Indicator for 0V-30V Lithium
LiPo / LiIon Battery LCD Display" for about $30.
It can be connected into either a discharge circuit to measure battery output or into a charging circuit to see how much charge in put into the battery. Note that you always put more charge into a battery than you can extract. That's to say the efficiency is always less than 100%.
This unit has no provision to turn the load on or off. It is not a load tester nor is it a charger. The Set Voff voltage is used to control when the TF01N goes into sleep mode. The idea is to build this coulomb counter into a battery pack so it's state of charge can be monitored and to minimize the power used by the TF10N. There is an internal current shunt that can be used for currents up to 3 Amps and after that an external shunt can be used up to 50 Amps.
It has no provision for an external power source, but rather runs on the battery pack it's connected to and that pack needs to have a voltage of more than 8 volts (up to 50 Volts).
QS-906 eBay title: .5v~12v Battery Capacity Meter discharge Tester 3.7v 18650 lithium lead-acid
14 Sep 2016
This unit came from the same eBay seller as the first non functional one,
but this one has a resistor marked R020
instead of a resistor marked R200 like the first (improperly assembled) unit.
See below for battery fixture.
Discharging an eneloop.
More later .. . .
2.65 AH vs. label capacity of 2.45 AH.
roughly works without calibrating.
Testing 18650 battery:
15 Ohm 5W resistor (4.1v / 15 Ohm = 273 mA) close to the 300 mA spec
for this Li-Ion battery rated at 1500 mAh,
which tests between 1450 & 1470 mAh (0.777 mAh shown)
K&J Magnetics parts to make connection to battery use 6-32 flat head screws.
0.625" dia (RA22CS-P) and 0.25" dia (R422CS-P)
This is also known as a ZB2L3 ZHIYU Battery Capacity Tester External Load Discharge Capacity Test (I have one of these on order 29 AUG 2016)
The current sense resistor can clearly be seen with matching markings on the PCB and resistor of R020.
This is a battery capacity tester that uses an external resistor as the load to drain the battery. The load resistor has nothing to do with the device calibration. Once properly calibrated the load resistor can be changed and the readings will still be correct.
Load ResistorsThe load should never exceed 20 Volts or 6 Amps because of the MOSFET switch. The MOSFETs are in parallel so the current can be higher, but I doubt as high as 12 Amps.
There may be a firmware limit of 15 Volts or 3.1 Amps.
The current through the resistor will vary from a maximum value set by the fully charged battery voltage and resistance.
For example an eneloop AA battery may start out at 1.4 Volts with a 7.5 Ohm resistor for a current of 0.187 Amps.
The power dissipated in the resistor is V * I or 1.4 V * 0.187 A = 0.261 Watts.
Since the supplied resistor is rated for 5 Watts this is no problem, but for more powerful batteries a resistor with a higher power rating may be required.
Circuit DescriptionThe tester uses a micro controller mounted under the 4-digit 7-Segment LED display.
An 8205s (pdf) Dual MOSFET each FET speced: 28 mOhms RDSon with a max rating of 20V or 6 Amps are connected in parallel and switch the load to battery positive (see Fig 2).
The battery current is sensed by R2 (0.2 Ohms) between the negative battery terminal and ground.
The battery voltage is sensed by (a guess - hidden circuit under display) a voltage divider R3 & R4.
Just above the Ah LED is a 0.1" pitch 4-hole pattern that's probably for in circuit programming of the uC.
The LM1117 (TI) Low Dropout voltage regulator is set for a nominal 3.3 Volt output (3.29 actual).
The uC is hidden so don't know make or model.
Fig 2 Input Schematic
Internal connection between R (J1-4)and +In (J1-3).
Guessing at R3, R4 Voltage divider.
R2 is the battery current sense resistor.
Q1 & Q2 in parallel to switch load to ground.
For all the parts except R2 the marking on the part
matches the nomenclature.
But for R2 the PCB is marked: R020
and the part is marked: R200
Photo here shows a resistor marked R020.
Battery and Resistor disconnected.
Step 1.Display shows: 0A0u (zero Amps and zero Volts), Q1 & Q2 are open so there is no load on the battery. The battery voltage drives the microcontroller ADC.
Battery removed and either left open or shorted. Which works best is TBD
When OK is pressed the zero calibration for both battery voltage and current is stored (but not saved)
Step 2.Display shows: 100u (10.0 Volts). Q1 & Q2 are open so no load on battery or heat in resistor.
External 10.0 Volt power supply to battery +In and -In terminals.
When OK is pressed the voltage at ADC V-In is measured and a ratio stored to get to 10 Volts.
Display shows: 200A (2.00 Amps). Q1 and Q2 are turned on. So if resistor installed it will heat because of the internal connection between R (J1-4) and+In (J1-3). But the resistor can be removed during calibration to avoid overheating it.
Connect positive source of 2.00 Amps to -In (J1-2 in Fig 2 above) and the ground to J1-1 (bottom R).
When OK is pressed the voltage drop across R2 is measured and stored.
Note the circuit impedance is a few tenths of an Ohm so the current source does not need to have a high voltage compliance, like was needed if you mistakenly try to calibrate using the battery terminals for this step.
When OK is pressed the above values are checked for reasonableness (how is a mystery) and if they seem OK they are saved in EEPROM in the uC.
Note this cal only needs to be done one time.
With the load resistor and battery connected power up the QS-906.
Press (+) or (-) to see the termination voltage and then press (+) and/or (-) to set the termination voltage.
Then press OK to start the test.
The first Ah display should be zero.
The first A display should be the battery starting voltage divided by the load resistor value.
The first V display should be the battery fully charged voltage minus a little for the effect of the load because of internal resistance.
Error CodesErr1: the battery voltage higher than 15V
Err2: the battery voltage is lower than the termination voltage setting.
Err3: the battery is unable to support the load current or of the test lead resistance is too large.
Err4: the current is too large (current is more than 3.1A.
Example (29 Aug 2016)eneloop AA cell after calibration using short in step 1 as above. Results before test finished:
Ah: 3.076 [ended at 7.761 a little more than 3X the actual value]
A: 0.665 (current still reads 4.01 x too high)
V: 1.24 (DMM: 1.277 V, implies a current of 1.277 / (7.5 + 0.2) = 0.1658 A
Still not reading correctly. Maybe because of the R2 value problem (PCB: R020, resistor R200).
A way to fix the current calibration is to change the current used for the cal and tweaking the value to get the current to read correctly.
I'd like to use this to test BB-2590 military batteries that are 4 cell Li-Ion, i.e. fully charged at 16.8 Volts, so a bit above the 15 V firmware limit.
So . . . . by cheating on the voltage calibration by say 17 V / 15 V and after finding the correct current for a normal cal change that by 15V / 17V.
This would require modifying the cutoff voltage by 17/15, but then the Ah would read correct.
Fig 3 Checking Current
Power Supply on + & - battery terminals
Note PS= 4.50 V, measure 3.94 V because
of resistance of test leads.
Fig 4 Checking Voltage
Load resistor disconnected.
PS on + and - battery terminals.
PS= 13.76 Volts (just under err1 voltage), measure= 13.98 V.
Note: err1 only happens when tester in run mode.
In startup mode I increased input to 18 Volts and the tester
displayed it without any error message.
29 Aug 2016 resolved Prior Problems - only read for background
Under $5 including shipping from Hong Kong.
It does NOT work as it should, needs updated firmware.
Fig 1 After OAOu:Short, 100u:10V, 200A:2A Cal
actual current is 1.37V/7.5Ohm = 0.182A, Display current is 0.659Amp, Why?
OperationAn external 5W 7.5 Ohm resistor is switched to the battery when the OK button is pressed and switched off when the battery voltage drops below the limit voltage indicated by Pnnnn.
After the battery is connected press + or - to change the value of P and when correct press OK to start the test.
YouTube video of QS-906 circuit running.
Maybe calibrated for Voltage (10V ref) and Current (2A ref) So the tester can calculate the current given the loaded voltage. If the test leads have too much resistance:
Err3: the battery is unable to withstand the load discharge current resistance is too large or line.
I have not yet figured out why some of the error codes appear or how to do the Calibration. If you know more contact me.
The tester has NOT been calibrated and the default cal is way off.
When testing a Panasonic eneloop pro AA battery with the 7.5 Ohm load resistor the tester shows: 1.69 A at 1.28 V equivalent to a resistance of 0.757 Ohm load. So way out of cal.
But when the same battery (fully charged) reads 1.409 V open circuit and 1.403 V with the 7.5 Ohm load applied. Actual current is V / R = 1.403 / 7.5 = 0.187 A = 187 mA
The battery internal resistance is (1.409 - 1.403) / 187 mA = 0.032 Ohms.
Short current current might be = 1.403 / 0.031 = 43 Amps (but not likely).
Tried cal (holding down all 3 buttons then connecting power. After start up displays: ---- (indicator for Calibration mode), 0.004 (maybe offset voltage) , OAOu (maybe zero Amps & zero Volts)
when OK is pressed the display changes to: 10.0u when OK pressed again display is 200A, and when OK pressed again reverts back to Ah -> A -> V -> Ah cycle. Doing the cal requires a power supply that can deliver both 10.00 Volts and 2.00 Amps.
But after trying to do the cal first with 10V and 1A and twice trying 10V and 2A the cal fails, i.e. when testing the eneloop shows 1.8 Amps, way too high.
Also tried with current in negative direction, but still get 1.8 Amps on the eneloop, not the 0.187A is should be. Maybe some factor of 10 error?
Note: with the supplied 5W 7.5Ohm resistor when the input is 10 Volts the power in the resistor is 13.3 Watts, and when 2.0 Amps are flowing the voltage drop across the resistor is 15.0 (the max rated input voltage) and the power in the resistor is 30 Watts.
This means the calibration must be done very quickly.
Maybe the Ah display is showing 10X the actual capacity. Will test an eneloop to completion to see if it comes our near 2.4 Ah X10 = 24 Ah.
The QS-906 shows 1.36 Volts and the DMM reads 1.348 Volts on the screw terminals. Shows 1.741 Amps Voltage drop across the 7.45 Ohm resistor is 1.308 for a current of 1.308 / 7.5 = 0.174 Amps
Note current is reading 10.0057 X higher than actual, so it looks like a 10x error.
Next to see how the battery capacity compares with the MH-C9000 (tested at 1.0 Amp load, but can be rerun at something closer to 0.174A.)
If 2.4 Ah capacity and 0.174A load then 13.8 Hours to discharge. About 12:30 now.
About 1:00, was not watching, the mode indicator LED is flashing for Ah, A and V instead on being on steady. Displays: 1.003 Ah, 1.692A (actually 0.1692A) and 1.31 V (cutoff set to 1.20 Volts). Do not understand whey flashing. Will let run longer to see if V display (and DMM) go down to 1.2 V. Load resistor has 1.264V voltage drop ( 0.168A) so still connected.
At about 11:00 pm the voltage was 1.24 V so not done. Next morning very fast flashing and the capacity shows at 19.71 Ah. Pressing OK twice shows the voltage as 1.26, i.e. the cell has recovered a little. Pressing OK some more times to restart testing shows: 0.000 Ah, 1.583 A & 1.23 V.
So, it looks like the reported capacity might be 10x the actual capacity. Now testing an eneloop at 200mA discharge to see what capacity it has.eneloop has 2480 mAh capacity when discharged at 200 mA, so the19.71 Ah (divided by 10 = 1.97 Ah is still way off.Tried calibration:
1. Short, 0A0u -> OK
2. 10 V, 100u -> OK
3. 2 Amps, 200A -> OK
but when fresh eneloop battery installed the displayed current is 0.669 Amps, much higher than the actual .174 Amps (384 % off).
The next day the display shows:
Ah: 7.125 (clearly much higher than 2.4 the actual capacity)
A transistor or other device can have it's resistance varied electronically and so acting as a programmable load. The mode of operation can be as simple as looking like a resistor, or a more useful mode looking like a constant current.
Amrel EL1132 Electronic Load
The quoted title of this paragraph is the same as the eBay
title for this made in China tester. eBay seller ayanhu81
(about $20). The same seller also has a "Four Wire Battery
Holder Battery Resistance Test for 18650 26650" that works with
the capacity tester. See a nicer BF-1L
4-wire battery holder below.
Note this unit has no charging capability, it's only a constant current load or capacity tester. Can also be used to test sources like wall warts, power banks, &Etc.
Technical Review -
Youku video (Mandarin): Use as Constant Current Load -
Youku video (Mandarin): Use as Battery Capacity Tester -
||Input power: 12 VDC <= 0.5 (0.1 typ)
DC power connector: 5.5 x 2.1 mm.
Power up display: 03.0u Volts & 0.21 Amps
|Fig 2 as received was in Constant Current
Load mode (Fun 1)
The top display stays fixed on Volts
Before inserting the power plug,
hold down the red button, then plug in power.
Turn knob so that Fun 2 appears, then press knob.
Now unit will come up in Battery Test (Fun 2) mode.
The other parameter that shows up after the Function is the beep mode on or off.
|Fig 3 after changing
into Fun 2: Battery Capacity mode
1.00 Amp constant current load, 14.4V cutoff
The top display rotates between: Voltage, Ah & Wh . . . .
This battery is a 4S Li-Ion BB-2590 (BT-70791BK1).
Probably 225 Wh, but we'll see.
Note the voltage displayed (16.07) matches what I read with a FLuke 87 DMM (16.07), so for a 1 Amp load and these short wires the IR loss is about zero.
|Fig 4 At end of capacity test
Note the State Of Charge bar graph on battery shows 1 bar here and in fig 3 above shows all bars.
Tester reads 6.747 Ah, 15.18V & 102.4 Wh
Test was run with 1.00 Amp load & cutoff @ 14.4V.
Watts Up Coulomb counter
Aux battery connected to allow working with voltages below 4.
With test leads shorted there's a reading ov 0.05 volts.
Org : gnd, Red:+9 drawing 5 ma Brn: Reset when grounded.
Aux cable at PowerWerx
This is fixture was laser cut from clear acrylic and the saw
tooth bed has markings for 34, 44, 49 & 65mm long
cells. It is a Kelvin fixture with separate wires for
forcing current and sensing voltage. The negative
terminals are spring loaded. Fastech BF-1L
|BF-1L battery Fixture with standard AA cell
on 44mm setting
|BF-1L battery Fixture w/o a battery
Any resistance inside a battery will generate heat during charge or discharge. It also limits the maximum current a battery can supply. Classically secondary batteries, like lead acid, are used for high current applications because of their very low internal resistance. I tried to measure the internal resistance of a Leclanché Battery with a Fluke 87 DMM and burned out the internal fuse because it could supply much more current than I expected.
This is very similar to, if not identical to, to concept of ESR (Wiki Equivalent Series Resistance) in capacitors. A high ESR means that the capacitor can not do as good a job as another capacitor with a much lower ESR.
The use of an amp meter to "Flash Amp" test No. 6 dry cells is based on looking for both charge and low internal resistance.
Table of Maximum Available Current for RC rechargeable battery packs nominally 7.2 Volts.
Internal Resistance is approximately Nominal Voltage / Flash Amps - "D" cell 1.5 V / 13A = 0.12 Ohms (but the resistance of the Flash Amp meter needs to be subtracted.)
Ryobi Tire Inflator Battery Internal Resistance - both are "18 V, 4.0 AH";
Not much different?
Black & Decker LST522 String Trimmer - these are all standard batteries, comparing 2.5 AH with 4.0 AH batteries.
PBP005 20.7 0.0451 459
SM8124 (20R) Battery Impedance Meter
I let the smoke out of my ESR-Cap meter when trying to measure the internal resistance of some 7.2 Volt RC batteries, so found this unit from eBay seller hkwisefield (eBay search for Internal Battery Resistance Tester).
The top switch is Off-Ohms-Volts and the bottom switch is 100V/200mOhms-20V/2 Ohms- 2V/20 Ohms.
There are two wires to each test probe (i.e. Kelvin connections) to cancel test lead resistance. But only a single terminal.
The test signal is about 1 kHz at more than 1 VAC.
By using an AC test signal the meter can use AC coupling for the resistance measurement keeping DC out of the test circuitry.
The AC test signal also has the advantage of not being influenced by voltages caused by thermal differences at metal junctions.
To replace the 9V battery peal the rubber case from the top side just enough to get to the battery compartment.PS this meter is also called "20R" and there is a very similar meter called SM8124 that's for measuring UVA and UVB light.
For a practical application see testing RC Car 7.2 Volt battery sticks for Maximum Current by measuring battery resistance.
SM8124A Battery Impedance MeterThe "A" version adds Kelvin connections to replace the single terminal connection used on the SM8124 version. So now each probe has two spring loaded terminals. This should improve the accuracy by eliminating the probe to DUT resistance.
Have this on order (Dec 2021, Rcvd: 2022 Jan 5) in the hope of testing the internal resistance of some tool batteries, like the Riobi and Black & Decker.
eBay title "Battery Resistance Voltmeter Internal Impedance Meter LCD Rechargeable SM8124A" from seller tangzhimin1008.
Came in a hard carry case which I like better than the soft carry case shown in the eBay ad.
Uses a single 9V battery.
Resistance test drive (measured with Fluke 87V DMM)
||% / month
||2 to 3
|Ready to Use Ni-MH
A battery analyzer has the capability to both charge and discharge a battery and make measurements of it's parameters, so is more than either a battery tester or a battery charger.
Cadex C7200 is a 2-bay battery analyzer mainly built for Ni-Cad, Ni-MH, lead-acid but also can do some Li-Ion battery stuff.
The HP 6633A can work in two quadrants and so can both charge and discharge a battery so software could be written to use it as a battery analyzer (or a battery simulator).
YouTube - 6632B battery test software - 6632 is 20 V @ 5 Amps, the 6633 is 50V @ 2 Amps. testing 1850 3 Ah cell.
Christie makes a number of battery analyzers, like TS-3997/U NSN: 6625-01-227-9615. This appears to the a relabeled CASP/2000 battery tester aimed at Lead-acid and Ni-Cad aircraft batteries. Not Li chemistries.
page created 13 Oct 2007.