DollaTek Digital Display Battery Capacity Internal Resistance Tester 18650 Lithium Battery Power Detector Module 4 Channes

I was a little hesitant at first to purchase this product as it is cheaper than a lot of the other options, and claimed to offer 4 cell testing at a price most others offer 2 cell.I have to say I'm pleasantly surprised as this get many things right that other chargers do not.UsabilityIn terms of setup, everything is ready to go out of the box. All of the battery holders seems to be isolated from one another, so no issue if your cells are mixed voltages, you can get right to testing.You have a couple of options to power the device, you can either use USB-C or the terminal connectors on the board. You can power either one or both of the type C ports, even running them off of power banks with no issue. All together a very painless experience.In terms of testing batteries, it would have been nice for some instructions on how to use the device, but the buttons are labelled on the PCB and there aren't too many options, so it's quite intuitive to use, so the lack of instruction was not a big problem for me.DownsidesThere are a few downsides to the product, but these are mentioned clearly in the description.It is not possible to set the charge or discharge current, these are both fixed at 1 Amp. You are able to adjust the discharge cutoff voltage, but not the charging cutoff (this would have been useful to allow the use of other battery types such as LiFePo4 cells). No deduction of stars as these were disclosed, but these extra features would have been very nice to have.The only other thing to mention is the fan is a little bit loud, but is easy to swap if you want to as it's on a micro JST connector, but this is more personal preference.ConclusionIn summary, I highly recommend this product. It is well built and easy to setup and use. The product page has lots of useful information and is accurate. You get good value for your money, as you get a 4 way charger for the price of a 2 way

Charger seems very effective.Provided me what seem to be accurate capacity and internal resistance numbers.Could do with instructions, but is easy enough to work out if you have even a small amount of knowledge or a little google magic. Shown here with an only Macbook Cell and a modern Lipo attached and testing at the same time.Biggest thing I would like to see it a change to the USB-C input, does not appear to have the resisters setup to make it work from smart USB-C chargers. Find from a USB-A to USB-C cable or a simple battery pack but won't run from a smart USB-C output. Would be great if the manufacturers took note of this and spent the extra 5 cents and some design time/retooling on making it more functional.

Was able to figure out how to use it quite quickly without instructions. I like its bare bones look. Works realiably