Cheap Battery Capacity Tester (ZB2L3) Case

prusaprinters

<p>This is a case for so called "ZB2L3" Battery Capacity Meters / Testers.</p> <p>Please note that I did several modifications to my device.</p> <p>You can't use this case without unsoldering the buttons, the screen and LEDs - it's not hard and definitely worth it!</p> <p>The aforementioned components need to be "raised" from the PCB (I use old IDE cables to do that).</p> <p>These devices can test batteries with voltages up to 15V at a claimed maximum of 3A (this current depends on the battery voltage and the load resistor(s)).</p> <p>You can adjust the minimum voltage of the battery (+/- buttons), the discharge process stops as soon as this set value is reached.</p> <p>During the discharge process the display automatically cycles through the current Ah, A and Voltage values.</p> <p>The large switch (MTS-103) on the side of the case is used to select between one power resistor and two in parallel (and no load at all). An image shows how to connect the switch.</p> <p>This way the discharge current can be adjusted.</p> <p>Schematic: <a href="https://easyeda.com/editor#id=%7C47f460a7c80549cbaf332b60b40b7d98">https://easyeda.com/editor#id=|47f460a7c80549cbaf332b60b40b7d98</a></p> <p>To power the board, a 5V supply is used (micro USB).</p> <p>My particular device had a voltage measurement error of about +100mV, thus I decided to investigate the issue.</p> <p>I found the voltage divider and replaced the 10k resistor with a 6.8k and 10k Potentiometer soldered in series. Now I can adjust the voltage divider ratio (this isn't perfect but works very well).</p> <p>The current measurement is much more accurate (good enough).</p> <p>I have included some images that show the case and PCB from various angles and during testing.</p> <p>I bought my board from here (and paid 1.80€): <a href="https://www.aliexpress.com/item/ZB2L3-Li-ion-Lithium-Lead-acid-Battery-Capacity-Meter-Discharge-Tester-Analyzer/32962214097.html">https://www.aliexpress.com/item/ZB2L3-Li-ion-Lithium-Lead-acid-Battery-Capacity-Meter-Discharge-Tester-Analyzer/32962214097.html</a></p> <p>You can find "chinglish" instructions on how to use the device in the description:</p> <ol> <li>The first test should be fully charged battery.</li> <li>Connect the battery to be tested positive to positive input, a negative input to the negative, can not be reversed (with load reversal may damage the circuit)! Load connected to the output of the positive and negative output, to work through the tester micro USB power supply (not available desktop or laptop USB powered), then the battery voltage.</li> <li>Direct start test need only one press of the "OK" button, the tester can automatically develop an appropriate termination voltage of the battery full charge voltage, and will start flashing after the test three times. Need to develop artificial termination voltage only when the battery voltage display state by pressing "+" or "-" buttons to modify the termination voltage display beginning with P, behind the representative voltage resolution 0.1V, set up after pressing the "OK "start testing.</li> <li>After the start of the test the tester will control the load of the electronic switch is turned on, the test data shows that the process will release capacity (Ah), current discharge current (A) and battery voltage (V) between the wheel was. When the battery voltage reaches the set cut-off voltage, load control switches off the tester display data stays in capacity (Ah) and above and the corresponding indicator flashes quickly together, now displays the actual capacity of the battery is discharging capacity, about the press "OK" to terminate flashing allows stable data display, press again "OK" button to return to the power-on state can just replace the battery test the next section ......</li> </ol> <p>Error codes and their meanings:</p> <p>Err1: battery voltage is above 15V</p> <p>Err2: battery voltage is lower than the termination voltage</p> <p>Err3: Battery can not afford to load or discharge current line too much resistance</p> <p>Err4: overcurrent (current exceeds 3.1A)</p> <h3>If you build this project and want to give me something back in return, I'd be extremely happy to see a post under "Makes"! :)</h3> Category: 3D Printing