IHD accuracy when showing Usage Now

IHD accuracy

I purchased this MR16, 12W LED bulb on eBay to replace my 50W haloggen and verify how bright it is and whether its light is going to flicker.

Why? As my hallogen driver is 12V, 20-60W I hear that bulbs should be in that range of driver’s wattage. I have tried 7.8W LED and indeed they do flicker a bit.

So this 12W LED arrived, but there is no marking on it saying it is 12W. It does not flicker, but its brightness is like those 7.8W, I would say.

Now, when I plug this supposedly 12W LED to its socket (the driver is already on), IHD display is increasing current usage reading by 2W only.

What is wrong in here?

You are expecting too much granularity in the the display. Its averaging over time, and there will be other devices in your house switching on and off or varying. A cheap bulb on Ebay is also very unlikely to actually be what it says / you ordered. 7W LED would be really quite bright for a little MR16.

I made sure other devices are not working, or if they are, I can see my stsrting reference point, as ex. 120W. When the LED is ON for more than 10 min and IHD is showing 122W I then OFF LED, and IHD goes down to 120W.

If you refit the 50W halogen and switch it on/off, do the readings differ by 50W ? Faulty meter is very very unlikely.

To check individual loads something like one of these is best.


Many brands to pick from.

I also recently for my aunt replaced some 12v halogen with LEDs and they worked terrible until we replaced the driver units with new LED Drivers designed just for LED’s the lamps were then worked fine.

When I play with hallogen it is jumping from 313W to 368W, hence showing 55W difference. The hallogen bulb marking is 50W.

in summary then, you bought shite from eBay sadly.