MakerHawkElectronic Load Tester - USB Load Tester 150W 200V 20A Resistor Adjustable Constant Current Battery Capacity Tester Module Intelligent Dischar

Very easy to use. You have to make up your own battery cables or do what I did and repurpose cables from a 12v inflator/jumpbox that went belly up.The device is limited to 185 watts (it’s just a smart heater). You can test an entire battery or individual cells.Videos detailing the actual use are found on the web. Essentially, the two silver knobs have to be fully counterclockwise before starting. Top is coarse adjustment and bottom fine adjustment. Start with top to get close to 185 and the fine to get as close as you can.Don’t go over as the device will alarm and you have to restart. With a standard 100Ah battery, you’re looking at 7.5 hours of runtime.You can see in the photos the data that is displayed while discharging and the end result. You’ll likely find your BMS will cut the battery at approximately 11.04v if you are testing a 12v battery.

Works good discharging my LifePO4 battery to verify capacity. Not the most well cased electronic load tester, but for the price good luck finding anything better.My only word of caution is to make sure the surrounding metal heat sink blades around the fan are bent away from the actual plastic fan. On my tester, one or two of the metal fins were bent slightly forward and was stopping the the fan from being able to spin. So make sure there ample clearance around the fan blades. Luckily I caught the issue in time. I thought it was odd my fan was not spinning and tried to manually spin it with my finger to see if it spin and quickly realized it was wanting to spin, but one or two of the metal heat sink blades was bent and touching into the fan blade and was preventing it from spinning. I bent the heat sink fins back away from the fan blade and it immediately started spinning and dissipating the heat from the tester.If I didn't catch that in time, I am sure I would have burnt the MOSFET chip up. So make sure the fan can spin freely when you use it!Otherwise, great little load tester the for the money!

I purchased this the test USB battery banks for Amazon reviews. The portable power supply type battery banks that you would carry for emergencies. When connecting the bank to USB C input absolutely NOTHING happens. It will not start the test regardless of what i try or how adjust the knows or the alarm settings. It may work great for testing batteries but USB input is a function it is supposed to have as well and it does not work at all!

I, and I would imagine like many of you, got to this product by Will Prowse - the solar and battery guru of YouTube. Anyway, this thing works really well. I immediately tested all four of my LIFEPO4 batteries, and I'm happy to say that all four tested well over the specified/advertised parameters! It took a while too - overnight for each battery (100ah each). I will say that at 185w, the unit heats up WAY TOO much! At 185w it was at 68 degrees Celsius, when I lowered it to 160w, the temp dropped to 55 degrees - that's a pretty significant drop in temp. It did increase the time to deplete my batteries, but I was not worried about leaving this run overnights. There are a lot more menus available - if you unplug the unit, press the button (the only one) and keep your finger on it while plugging it back in, you'll get a menu to change a lot of settings - so you may want to explore that. So far, it's working well and it is very accurate (as compared to my Fluke meter and another smaller more inexpensive meter). I don't know what it will be like long-term, but so far so good. As long as it dies within an acceptable amount of time, I'm pretty sure I'd buy another one.

Works as I needed it to.

This thing is cheap but useful. The interface, controls and instructions are all absolutely terrible but you can watch YouTube videos that explain how it works. Once you have it figured out and set the way you need it's OK. Quality control could probably be better as the first one I bought died within minutes. I've used the replacement quite a bit (weeks) and it's still fine.

There are two versions of this product - one is set for a maximum load of 150 Watts the other is set for 185 Watts. I received the 185 Watts version, however, you can change the maximum. I tested my 48 Volt trike battery. As I increased the load current to 5 Amps the battery voltage dropped to 10 Volts - yep, the battery is bad. When I reduced the load, the battery went back to 48 Volts.

I have a lot of AGM and LiFePo4 batteries going into or coming out of battery backup systems. I always wanted to know what the state is of both new and used batteries. I needed to determine if some of the used batteries still had usable capacity, do the new batteries deliver the rated capacity? This tool is perfect for those tests. It is a constant current load, which is perfect for measuring capacity. The load is variable from 0.001A to 20.0 A (within rated wattage limits), it displays input voltage, current, watts, watt hours, amp hours and run time in hh:mm:ss. BE AWARE I was introduced to this device via a YouTube video where the author incorporated a separate battery cutoff module as he indicated this device does not remove the load when the (adjustable) minimum voltage is reached...that it only sounds a buzzer. Since the device he was using looks exactly like this one I can only assume it was the same. His comments in the video are WRONG. Either he didn't set the minimum voltage correctly or he had a defective one. When the minimum voltage (configurable from 0 to 190) is reached a buzzer sounds AND the load is removed (0.0 Amps). Hence if configured correctly you can set and forget (for a reasonable time) without fear of ruining the battery from discharging too far. This is one of the more valuable (not costly) tools in my battery maintenance kit.