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🔌 Stay powered, stay ahead — never get caught off-guard with QWORK® Battery Capacity Tester!
The QWORK® Battery Capacity Tester is a high-precision voltmeter and ammeter designed for professional-grade battery monitoring across a wide voltage range (8V-80V) and current up to 100A. Featuring a large backlit LCD, it provides real-time data on voltage, current, consumed power, and battery capacity, with automatic data storage for convenience. Compatible with multiple battery chemistries and ideal for automotive, marine, RV, and portable applications, it ensures you maintain optimal battery health and avoid unexpected power failures.








| ASIN | B08HWFPGL5 |
| Best Sellers Rank | 115,235 in Automotive ( See Top 100 in Automotive ) 130 in Car Battery Testers |
| Brand | QWORK |
| Colour | Black |
| Compatible Devices | Devices with battery banks (8V-80V, 0-100A) |
| Country Of Origin | China |
| Customer Reviews | 4.3 out of 5 stars 339 Reviews |
| Item Weight | 250 Grams |
| Item weight | 250 Grams |
| Manufacturer | QWORK |
| Manufacturer Part Number | WD3941 |
| Maximum Operating Voltage | 80 Volts |
| Measurement Type | Voltmeter |
| Min. Operating voltage | 8 Volts |
| Minimum Operating Voltage | 8 Volts |
| Model Number | WD3941 |
| Power Source | Corded Electric |
| Power source | Corded Electric |
| Specification Met | Specifications Met |
| Style | Voltage |
| Style Name | Voltage |
| UPC | 792332966894 |
| Unit Count | 1.0 count |
W**G
Good monitor. Well made
This is working fine on my 24v lithium system. I am using it to monitor two 12v 110 amp lithium batteries in series (24v)i have been using it tor a few months now with no problems
P**0
I bolted it directly to the battery. 4m cable !
Great 4m cable !!! The 350A model is taller than the 100A model Be careful not to bend it! *My tips* (Not expert) Mainly for motorhomes: Note. To set backlight always off: Hold down both arrow buttons together for 3 or 4 seconds. To later temporarily illuminate, press the “A” button, briefly. To set backlight always on: as above. (It will flash on and off during charging.) but when the resultant current (explained later) flow is below 100mA, the backlight always automatically turns itself off. Note: The level of current shown on the “A” screen depends on two factors: 1. The current now going into the battery which perhaps depends on the solar charger and the Sun and the 240 V charger. 2. The current flowing out to devices which opposes 1. to give the resultant current. (The meter will detect tiny currents drawn by such things as the standby current for the solar controller and Bluetooth devices.) Note: The Current Screen has two displays: “A” and “Ah”. Pressing the A button swaps between them as shown on the screen. “A” shows the current now flowing. Note: Perhaps you can use the following method to set up the meter without discharging your battery to zero Volts. * Set the meter to remember your battery's claimed capacity (Ah)* 1. Wake the backlight if needed by pressing the A button. 2. Show the “A” screen on the meter if needed (Current Mode) by pressing the A button again. 3. Show the.”Ah” screen on the meter by pressing the A button again. (Setting Mode) This shows what the meter thinks your batteries claimed capacity is. 4. Correct this figure if needed by holding down the A button for 3 seconds to enter the blinking setting mode then pressing the arrow buttons to match the “Ah” written on the battery. 5. Press the A button again to save and exit back to the “A” screen. *Set the meter to show when your battery is full (100% capacity)* 1. Charge the battery to full. 2. Wake the backlight if needed by pressing the A button. 3. Press the % button to show the present presumed capacity. 4. Hold down the % button for 3 seconds to correct to “100%”. Done!
K**R
Tiny instructions! Otherwise ok.
The monitor works OK when combined with a shunt. My only gripe is with the instructions which are difficult to read as the font is TINY! Also the symbols both on the monitor switches and in the instructions are almost too small to decipher.
A**R
New customer
Great battery monitor, installed to visually monitor my vehicle battery, especially in winter months, no big screen, fits neatly here I can easily monitor performance and potential degradation.
M**M
Wanted a fuel gauge for a 24v lithium battery
Found this gauge and shunt quite easy to install . Not sure if any reason not to do it the way I have . I found the bolt on the shunt was the same thread as my renogy 24v 100ah battery . I just removed the bolt in the battery and took the nut off the shunt and bolted the negative side directly to the battery as picture . One thing to note is you need a thin piece of red wire not supplied to go to the positive of the battery . The gauges tell you battery percentage , amp hours remaining, voltage, the amps going in or out of the battery. Would have liked to see wattage but for the price it's ok
T**N
Works really well.
Very pleased with my purchase. Was simple to install and use and seems to give clear accurate reading of the battery state.
C**R
Not very good
It works. It doesn't work
M**Y
No bracket
No idea if it works or not yet because I'm still making a bracket for mounting it into the van. If I'd known earlier, I'd have sent it back for a refund. It's become a hassle and I expected a device like this to come with a mounting bracket.
I**.
Honesty
No issues, installed it in my boat, looks really sharp and has been very functional.
R**M
Très bon testeur de batterie!
C'est exactement un testeur de batterie que je recherchais. Pas trop d’options inutiles et pour un prix très compétitif. Comme l'appareil fonctionne avec un très bon shunt, il surveille à la fois la charge et la consommation de courant, vous donnant ainsi un aperçu précis de la capacité disponible de votre batterie. La tension actuelle (V), le courant (A) et la capacité disponible (Ah & %) peuvent être lus.
A**N
Easy install and works perfectly
This battery meter allowed me to convert my electric lawn mower to lithium batteries and keep an accurate view of the battery level. The installation is incredibly simple. The instructions are adequate if you have some familiarity with electronics and wiring. The included wiring harness is extra long, high quality, and is even UL listed. The only thing NOT included in the kit is a short segment of thin wire to provide positive voltage to the meter.
T**S
Handleiding
Leuk dingetje, doet zn werk. Maar de leesbaarheid en duidelijkheid van de handleiding laat te wensen over. Met name de symbolen en de vertaling in het engels zijn niet goed.
D**F
Übersichtlich und gut
Ich mag diesen Shunt sehr. Habe zwei davon schon seit Jahren im Einsatz und sie tun was sie tun sollen. Das einzige was mich stört: die helle Hintergrundbeleuchtung blinkt beim Laden und leuchtet beim Emtladen. Nur im Ruhezustand geht sie aus. Leider kann das nicht ausgeschaltet werden. Somit muss der Shunt an versteckter Stelle verbaut werden damit nachts nicht das ganze Wohnmobil grün erleuchtet wird. Oder kennt jemand einen Trick um die Hintergrundbeleuchtung auszuschalten??
Trustpilot
3 weeks ago
1 month ago