PEMENOL DC Electronic Load Tester 35W 5A， Adjustable Constant Current Aging Tester Discharger Voltage Current Power Battery Capacity Display， LCD 18650 Battery Charger Tester

I have always been interested in things that were battery powered. I can’t tell you how many “Battery testers” I have built in my lifetime. Most of them were simply discharge/charge type units that were pretty crude! As most people know NiCad batteries have a memory effect that needs to be dealt with from time to time or they will lose their original capacity. I still use NiCad’s over NMHD a lot because of their high discharge capability. This Load Tester is great for not only testing these batteries but as a way to exercise them without damage. (You have to be careful about how far you discharge any rechargeable battery). Like a lot of people these days I have several USB type power banks for charging devices while on the go. I have always wanted to know if these things are really up to their rated capacity. This device is built for this job! I have probably put 30 to 40 hours on it testing my “Power Packs” yielding sometimes surprising results. The cool thing about this Load Tester is how easy it is to change the load. Just turn the potentiometer to change the load on the “Device Under Test” (DUT) then all of the parameters are updated using the new discharge value. Most of the time, I am just interested in the amp hour capacity of the battery. This just requires you to set the discharge rate, connect the DUT and push the start button. For these power banks I set the Low Voltage Alarm to 4.5 volts and let the test run until either the pack activates its own low voltage shut-off or the tester’s Low Voltage Alarm goes active. Then all you have to do is look at the display to see the amp hour value. By the way, the display is backlit in a pleasant blue color and is very readable even under my work bench’s bright led lights. I have only been talking about one application of this Load Tester. Just about any battery or battery pack, other than vehicular batteries, would be a candidate for use with this tester. I have many different types of rechargeable batteries and by using this Load Tester on them once in awhile I can dispose of bad ones before they cause any trouble. Of course you can load test non rechargeable cells as well. I suggest that you read the full data sheet to find out about all of the functions available in this device. There are way too many features to describe here. I plan to put this device into a 3-D printed box. Unfortunately in order to do that I will have to remove the TIP122 transistor, fan and heat sink from the board and relocate them. There are only two things that I would like to have changed on this tester: 1) Have the heat sink assembly on the bottom of the board. 2) Have more than one speed for the cooling fan. It currently only has off and on and during the discharge operation it activates about every 5 seconds. This is a GREAT little instrument that I wish I had access to years ago. I highly recommend it!

I liked that I could set it to provide a constant current load for testing small power supplies; I liked that I could use it to record battery amp-hour capacity; I liked that it can easily be powered from 5 Volt supply using micro USB cable; I liked that inputs for connecting to DUT include USB Type A connector and screw terminal strip; I didn't like that there were no instructions included on how to use it; I didn't like that when I did download instructions some were difficult to understand for some functions; I didn't like the obscure calibration procedure to correct voltage and current inaccuracy. All-in-all it will be a useful load tester if I am able to remember the intricacies of the discerned yet poorly translated instructions. All functions are not intuitive.

This is a wonderful little load tester, and I can't wait to test it's full capability. I have some old rechargable battery packs laying around and wanted to make sure that they will still perform well, I was able to test them with this to see how badly the voltage dipped when under their max load and this gave me all the information I needed. Pro's: Easy to use, very intuitive controls and easy to read display pulls power from a separate source in order to not skew the data from the load potentiometer makes it easy to adjust the load to test for different conditions shows amps, watts, amp-hours and time elapsed for all the data you could need. Up to 5 Amps or 35 watt capability, so will work for most small projects you would want to test. has a micro usb b connector for unit power or can be powered from the 5v pads Cons: Wish it had a case for the unit as the pcb and all components are exposed. At least it has feet to sit on to raise it while powered on All in all, a very good cheap unit that will find a lot of use in my shop.

I bought this to test 18650 batteries and other small loads. It worked great for a few weeks and then stopped applying a load all of a sudden. I contacted the seller and after some useless back and forth emails they stopped responding. Very disappointed with longevity and customer support. I like the flexibility and function control for different load types and cut out limits, I just wish it had lasted longer.

Found all declared functions are actually here. I was able to set load current from 0 to 2.5 A, was afraid to set more current draw from my USB AC power supply as it may accidentally kill my source. At some moment built in fan controller started to turn on/off heat sink fan, but temperature of heat sink has been kept well below specified limit of 80°C. LCD display is bright enough, can be seen without external light. Some important warnings to potential users: - Don't try to use '+' and '-' buttons to adjust LOAD current. I was lazy to read manual at first and as a result unintentionally changed current meter calibration settings. Good feature of this device that it can be restored back using external multimeter. - Use galvanically decoupled power supplies. External USB power supply is required for device to operate and it should be decoupled (no common ground) from power supply you are going to test with this electronic load. Even if you accidentally forget about this requirement nothing serious will happen, only tester readings (both voltage and current) will be wrong. Pros: Ability to measure not only load power, voltage and current but battery current capacity as well (in mAh). Extra input to connect any two-wire power source under test (not just USB). Easily adjustable load current with multi turn resistor handle. Clear and bright LCD with back lit Can be re-calibrated with external multimeter Reasonable price Cons: USB power cord could support software control by PC over USB. But I suppose it would increase price for this load tester. Heat sink fan operates either at full speed or completely stopped. Linear control would be more comfortable, but for DIY purposes it's completely fine.

You may need to measure the current drawn by the load and calibrate. Then it is accurate. I wish it could draw more than 35 watts. Takes a long time to measure a large battery. I would recommend it.

Might actually work but will never know sending it back Link Provided for instructions did not work - Norton says " BAD "

I have been using this to capacity test some 18v Makita batteries, and it has worked very nicely. The accuracy is pretty good overall, and I think excellent considering the price of the unit. One key feature that this has that some of the more expensive/high power units lack is a low voltage cut-off - some just have an alarm, but don't turn off the load. This unit cuts the load and signals an alarm which is quite nice. The user interface is a bit clunky due to having only 4 buttons, but is reasonable once you get used to. I have tested the undervoltage, over-power, and (accidentally) the reverse polarity protection. Everything works as expected. It does get pretty toasty, so I did have an extra fan blowing over it when I was running it at 30+ watts, but I don't know if that is required or not. It's a great value for the twenty dollars it cost.