--- product_id: 318372905 title: "QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV" brand: "qwork" price: "$10.27" currency: USD in_stock: false reviews_count: 8 url: https://www.desertcart.us/products/318372905-qwork-battery-capacity-tester-battery-monitor-voltage-range-8v-80v store_origin: US region: United States of America --- # 0-100A high precision current detection 6.5ft/2m custom cable 8V-80V voltage range QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV **Brand:** qwork **Price:** $10.27 **Availability:** ❌ Out of Stock ## Summary > 🔋 Stay powered, stay ahead — never get caught off-guard! ## Quick Answers - **What is this?** QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV by qwork - **How much does it cost?** $10.27 with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/318372905-qwork-battery-capacity-tester-battery-monitor-voltage-range-8v-80v) ## Best For - qwork enthusiasts ## Why This Product - Trusted qwork brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Smart Data Retention:** Automatically saves your last test data, so you never lose track of your battery’s performance. - • **Precision Power Insight:** Monitor your battery’s voltage, current, and capacity with pinpoint accuracy for smarter energy management. - • **Versatile Compatibility:** Perfectly engineered for cars, RVs, boats, e-bikes, and caravans—one tester to rule them all. - • **User-Friendly LCD Display:** Large backlit screen delivers real-time data on voltage, amps, consumed power, and capacity—even in low light. - • **Fuel Gauge for Your Battery:** Visualize battery health like a fuel gauge—know exactly when to recharge or replace. ## Overview The QWORK® Battery Capacity Tester is a high-precision voltmeter and ammeter designed for 8V-80V batteries with up to 100A current detection. Featuring a large backlit LCD, a 6.5ft custom cable, and automatic data storage, it offers versatile compatibility across vehicles, boats, RVs, and e-bikes. This tool empowers professionals and enthusiasts alike to monitor battery health like a fuel gauge, ensuring optimal performance and peace of mind. ## Description Accurately monitor battery voltage, current, and capacity with this versatile tester. Suitable for a wide range of applications including cars, boats, and RVs. Review: 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. Review: 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! ## Features - Battery Condition - High precision Current detection. You can read the battery bank like a fuel gauge, and also clear note the battery status. - LCD displays - Large backlit LCD displays multiple battery information (voltage, current, consumed power and battery capacity) - Data storage - designed to automatically store the last testing data when the system shuts off Voltage Capacity - voltage range 8V-80V and current range 0-100A - Wide Application - It is suitable for mobile and portable equipment, balance cars, cleaning machines,e-bike, instruments, RV, Boat, Caravan etc. - 100% Satisfied Service - Sincerely hope our products could give you a good experience and some help. Within a month you purchase this product, you can enjoy a worry-free return service. And any questions feel free to contact us, we will try our best to help you. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B08HWFPGL5 | | Best Sellers Rank | 166,385 in Automotive ( See Top 100 in Automotive ) 208 in Car Battery Testers | | Brand | QWORK | | Colour | Black | | Country Of Origin | China | | Customer Reviews | 4.4 out of 5 stars 985 Reviews | | Item Weight | 250 Grams | | Item weight | 250 Grams | | Manufacturer | QWORK | | 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 | ## Product Details - **Brand:** QWORK - **Colour:** Black - **Item weight:** 250 Grams - **Power source:** Corded Electric - **Style:** Voltage ## Images ![QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV - Image 1](https://m.media-amazon.com/images/I/71drQVfQnsL.jpg) ![QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV - Image 2](https://m.media-amazon.com/images/I/61JJnrYQnbL.jpg) ![QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV - Image 3](https://m.media-amazon.com/images/I/61vvdVoaG1L.jpg) ![QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV - Image 4](https://m.media-amazon.com/images/I/71a5ThB13pL.jpg) ![QWORK® Battery Capacity Tester, Battery Monitor, Voltage Range 8V-80V and 0-100A Sampler base, with 6.5ft / 2m Custom Cable, for Auto Car Motor Boat Caravan RV - Image 5](https://m.media-amazon.com/images/I/81DpcoCDptL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Can the flashing screen be turned off when charging?** A: Long press the left and right keys at the same time. **Q: Unit appears to go to sleep mode, meaning there is no display at all with voltage applied. button press turns on the device then works ok. Fix for it?** A: When the battery is neither charging or discharging the screen turns off. When not connected to the grid, which is the usual case with me, generally the screen will go dark around sunset or sunrise when the demands from my RV equal the power produced by my solar panels. When connected to the grid and my battery disconnected from the RV, the screen will be dark half the time. It lights up when my Morningstar charger decides my battery needs a modest "topping off." It should be noted that the screen goes dark even when the charger is in float mode, the current being so modest as to be almost undectable. **Q: Does it display 1/10, 1/100 or 1/1000 of a volt?** A: 1/100. **Q: how long has anyone extended their display cable** A: I added 15ft to my original 13ft cable using CAT5 cable - just cut the existing cable in half and soldered the CAT5 in the middle. The original cable has a shield wire that connects to one of the pins; my CAT5 cable didn't have a shield but I combined the four white wires in the CAT5 and used that combined wire to connect to the shield wire. That left 4 wires in the CAT5 to connect to the remaining 4 wires of the original cable. The result worked fine. ## Customer Reviews ### ⭐⭐⭐⭐⭐ New customer *by A***R on 4 March 2026* 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. ### ⭐⭐⭐⭐⭐ I bolted it directly to the battery. 4m cable ! *by P***0 on 7 March 2025* 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! ### ⭐⭐⭐⭐ Tiny instructions! Otherwise ok. *by K***R on 15 July 2025* 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. ## Frequently Bought Together - QWORK Battery Monitor Voltmeter Ammeter, Voltage Current Range 8V-80V, 0-100A Voltage Current Meter with 6.5 ft Custom Cable - EZGO RXV&TXT Smart Charger - 48V 13A and 36V 18A Trickle Battery Charger, Delta-Q 3-Pin, Lithium, LiFePO4, Lead-Acid AGM/Gel/SLA - LiTime 12V 100Ah LiFePO4 Battery BCI Group 31 Lithium Battery Built-in 100A BMS, Up to 15000 Deep Cycles, Perfect for RV, Marine, Home Energy Storage（4 Packs） --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.us/products/318372905-qwork-battery-capacity-tester-battery-monitor-voltage-range-8v-80v](https://www.desertcart.us/products/318372905-qwork-battery-capacity-tester-battery-monitor-voltage-range-8v-80v) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-05-16*