MakerHawkBattery Load Tester - 150W 200V 25A USB Load Tester 4-Wire System Adjustable Constant Current Voltage Discharge Lithium Battery Capacity Tester Electronic Load Tester

Plug in the 12v power supply to the back.Prepare your phone for the QR code to download the app if you want to monitor the settings remotely (you can operate the buttons from the app). I had to pair with specifically one of the two new bluetooth broadcasts. I believe one is for android, the other for iphone. The app will show some insane 600v measurement graph-- you can zoom in with finger gestures to get down to the typical 12V range.To test battery capacity:Screw down the fork leads to the front left green connector block. The black fork is closer to you- red closer to fan. Make sure you open the connector block first with flathead screwdriver otherwise you'll likely screw down the forks in reverse by a counterclockwise motion and the forks (or USB board) will dip up at an angle.Attach leads to battery (or cell). Set the cutoff voltage to your particular battery (or cell). You need to know this!!!For a 12V Lifepo4 battery capacity test above 15aH battery: make sure it is fully charged. set cutoff to 10.5V. clear data (this just clears the test metrics and gives clean slate). You'll want to use CC to test capacity. Set CC to max allowable: you will probably start at 13A and work up to the 14A range (if you're in no rush, set it lower). Keep note of the MOS temp range and don't exceed 99C. Don't even up that in the settings. You can get 14.3A+ if you prop up the tester and have a fan blowing under the heatsink and the mainboard. Try not to exceed 180W. This advice is for 75F ambient. Be more conservative with the amp settings if ambient is hotter, you'll burn up the MOSFET under the heatsink. If you trip the temp alarm too much it will stop the test. You can resume, but you need to lower the amp draw first or fix your cooling. Don't push it!You can test a 314Ah 12V battery in under 24hr with the above method.

Like everything "made in China" based on Western technology, it is made so-so and works at best at 70-80%, and also requires revision. This speaks to the level of their engineering. The PCB board design is terrible. The board is too thin. The cooling fan is not designed for it and does not have a stiffener on the back side, and as a result, the board is strongly bent, which will certainly affect its durability, the appearance of cracks, etc. The whole design looks flimsy and unreliable. After the modifications that you can see in the photo, this device begins to look like something working that can be used without risk to life and your property. The language of the documentation on the back side is Chinese. You are selling the product in the USA, where the official language of the USA is English. You are violating US laws and Amazon policies by selling goods in Chinese in the USA! We are not going to learn your Chinese. p.s. But, it works and fulfills its purpose. That is why I give three stars to that product, but not two, or one.

Value for money:The unit requires power and no power supply is included so you can't use it "out of the box". You have to supply a 12V @1 amp power supply or provide a USB C power brick. A USB cable is included but no power brick. It's a very capable unit that measures everything you can think of. Fine print on the display is hard to read under some light conditions. I ran it at 12V @ 10 amps for an extended time with no issues. I wouldn't use it with power sources over about 50 volts do to the shock hazard from exposed traces. Overall I like it and would recommend it.

It's fairly simple and easy to use. Programming the load was simple.

Works good but a little small for what I was using it for. Got the 180w instead.

bought a 2nd. doing battery run downs of a certain type of battery.I found the voltage measurements to be dead on.There are a few quirks, but minor learning curve.

I know this thing is recommended a lot online, but for my use case it didn't work. I could not get it connected to my computer either through Bluetooth or USB. Some reviews had mentioned that it was easy to kill the serial to USB adapter and I wonder if my unit was a previous return as it was missing some items in the box and the computer connection would not work. I needed that, so I returned it.

Works well providimg a dummy load of 150 watts to test battery capacity. Menus are on screen. User interface mot the best, but not hard to figure out