The RND labs RND320-KEL103 is a programmable electronic load, specified up to 120V, 30A and 300W. Its a relabeled KORAD KEL103. The only differences are the labeling and some stickers on the outside and a lower price tag for the moment. There are multiple reviews on Youtube and at the EEVblog forum discussing the original KORAD KEL103 as well as the also relabeled Tenma 72-13210. Since I had to deal a couple of times with almost lethally constructed and wired devices of chinese origin, I´m usually taking a look inside before the first switch-on whenever possible.

That is easy with the KEL103. Four screws fix the plastic back frame and another four screws on the bottom side fixate the hood. And here´s how it looks:

The first impression is a good one. A clean structured front plate and a easy readable display.

The front connectors appear more massive than they are, and due to missing side-holes and 4mm front-holes they don´t take wire or 4mm Banana connectors. The quality of the plastic front appears to be good and that of the back frame ok. There´s a sunk-in transport handle on the left side. Fold-out feet allow for tilted placing on the bench. The back panel holds more connectors, a IEC inlet, a second set of signal connectors as well as sense inputs, a USB input, RJ45 LAN and a 9-pole DSUB RS232 connector. The software comes on a CD or may be downloaded from the websites.

Under the hood two cooling blocks with fans come into first sight, as well as the transformer.

The larger cooling block accomodates on both sides four IRFP260 MOSFETs and their associated source resistors. The smaller cooling block houses the measurement shunt.

The transformer is a incapsulated version and a hard power switch is installed.

Manufacture, PCB and solder joints look decent. All is covered by a shiny layer of laquer, which makes identification of parts tagging a bit difficult, but at least they didn´t scratch off the identifiers.

In case of a service one has clearly greater chance for success.

I could test the hard- and software only shortly. The first impression is a really ok, especially accounting for the attached price tag.

In the meantime I could perform a couple of tests, mostly of the battery mode.

The operating manuals of all three loads are unfortunately quite basic, so that its not at all easy to understand the logic of the programming. Once you got around it the RND can be programmed quite fluent. The original software makes things a bit easier also.

For battery tests a little logging program named ´TestController´ is very helpful.

http://lygte-info.dk/project/TestControllerIntro%20UK.html (Download-Link at the end of the site)

The program is discussed on eevblog  under "Program that can log from many multimeters" .

The Korad and Tenma loads are already listed in the program device list.

You can add the RND by yourself using a editor and copying the following text lines at the beginning of the file ´Korad KEL103.txt´ in the subfolder Devices.

#metadef
#idString RND 320-KEL103
#name RND KEL103
#handle KEL103
#replaceText MaxPower 300

After restarting TestController the RND should connect with the program.

The program allows for logging discharge curves of rechargeable batteries. This way one can evaluate their condition and actual capacity.

rem. besides the electronic loads many DMMs are already listet such as my Siglent SDM3065X and the Brymen 867s