Maxmartt Battery Tester USB Adjustable Constant Current Electronic Load Battery Capacity Tester Module 150W 200V 20A Electronic Load Battery Tester Discharge Tester Capacity Testing Module

top quality very nice product it functions as discribed this is like my fifth one i have bought well worth the money 5 stars here thanks

I used this to check out all of my USB chargers and cables. Several cables were very poor for charging, dropping output from 5V down to under 3V with the load at 2A (still may be OK for high speed data, though). While the measurements are accurate, matching the power on a SOOPII 100W USB cable (with power display) and an Eversame USB tester, I dropped a star for the bad documentation - several errors, including having the coarse and fine adjustment knobs swapped.

Shorted out internally, would automatically trip the BMS in my battery the moment it was hooked up.

I liked that I was able to pick this up for under fifty bucks and can see what the actual capacity of a battery is without having to guesstimate. There are lots of ways to calculate power capacity, but this is pretty convenient, other than it is basically turning all power into heat, and it is limited to 185 Watts. If you want to test the capacity of a large battery, there are better tests, like cranking amp and cold-cranking amp tests. It would be nice if this came with a battery holder for testing AAA, AA, C, D, and other common small battery sizes that don't have leads.

I don't have time to write as much about this product as it deserves, but seeing that no one else has yet reviewed it, I felt compelled to say that it works very well. I can find no fault with it, whatsoever. The English language instruction sheet is a little "rough," but I found it very helpful, just the same, given how intimidated I was with my first impression after unboxing it. It's really a very cool instrument for measuring the true capacity of battery banks as well as the voltage and amperage-handling ability of AC-to-DC power adapters.

This tester allows me to do a simple test on my ebike batteries for AH capacity without having to ride them til they go flat. The time savings is worth what I paid,.Normally, I'd use a wattmeter to measure the discharge or charge cycle. That method is a bit unreliable because of the wide variation in wattmeters. Also tedious if it takes 40 miles to empty a battery. Here, all I do is hook up a battery, and come back when its done.While the current can be set from 0 - 20A, the tester can only dissipate 180 watts, so ebike batteries are limited to 2-4 amps, depending on their voltage. A capacity test of 2A -4A is close to how the internal lithium cells are tested by the manufacturer. It corresponds to a 100-180W load on your ebike, so it's on the light side. Depends on how fast you ride. I ride slow, so it's close enough for me.It does seem to hold a constant current as the battery discharges. I checked the curremt with a Extech clamp-on ammeter and it's close enough.

The unit does a great job of measuring battery capacity but the voltage readings for cut off voltage is way off. To set for 2.5v cut off I have to set meter to 1.8v!?! And it is still not exactly dead on. Was able to check some older lithium cells and it did a good job. Make sure you double check settings with a good voltage meter.

first one I received did not work, the replacement I received worked once and then burnt out, what more can I say

It worked ok at first, but after 2 battery test, the load is not working anymore ! LCD turn on, but nothing else happen.