Maynuo M9812 Programmable LED DC Electronic Load

Thursday 02 October 2014

Maynuo M9812 Programmable LED DC Electronic Load

Front Panel with case removed
Back panel
Top view with case removed
Internal resistors and fan
Front panel binding posts
On its stand
DC Load mode
Battery Testing mode

We have now purchased a Maynuo M9812 Programmable LED DC Electronic Load rated at 0-150V 0-30A 300W.

We had planned to buy a DC load for to use for testing battery drain, battery controllers and for our new solar data logger system which is slowly progressing. We looked at a very similar DC load from B&K Precision, model 8500 but this was over £1100 from UK suppliers compared to the cost of the Maynuo M9812 unit which was £304 plus import costs of £80.

After looking at the specifications and online reviews and video teardowns of both units we decided to order the cheaper model.

There is an optional TTL-USB isolated adapter available for around £80 but we have designed our own to fit into a DB9 plug on the back of the unit which will give us a USB com port to allow us to the control and logging software which Maynuo provide as shown below:

Software Screen Shot
Click to expand

The DC load has a very useful function for battery testing which allows us to set a preset current draw and the load will consume this until the battery voltage drops to a preset level.

DC Load Features

  • Six high speed operation modes: CC,CR,CV,CW,CC+CV,CR+CV
  • Over current, over voltage, over power, over heating and polarity reversal protection 
  •  High-luminance vacuum fluorescent display (VFD) screen with two line, four channel display
  • Intelligent fan system will automatically activate based on changing ambient temperatures
  • Soft-start time setting, activating the power supply in accordance with the set voltage value 
  • Battery test and short-circuit test functions
  • Capable of rising edge and falling edge dynamic testing
  • Supporting external triggeron either input or output
  • External current waveform monitor terminal output terminal
  • Supports remote voltage compensation and multi-data storage
  • Power-on-self-test, software calibration and standard rack mountable
  • LED mode for LED power driver test, steaday reading, compatable with simulating the capacitances sensitive driver
  • Edits arbitrary waveforms in list function
  • Available with RS232/RS485/USB serial interfaces.

Manufacturers web page:

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