Excessive current draw flattens battery

[mr_p_pkight]

I have a Pumpkin Head Unit in a VW T5 Transporter. It draws almost 500mA when OFF from the B+ connection, and has done so from new. This makes it impossible to leave it connected to the battery because it will flatten it. I've had to run it from switched power, so I lose all status information every time I turn the engine off. As you can imagine, this makes it a pretty crap product to use.
I just assumed it was really bad design, but I found someone else on the forum had a similar problem, and from about the same time. The solution for them was that the motherboard was faulty. So, is 0.5A normal for your products, or do I have a sick motherboard?
Model number on box is 13-MS0353A
Serial number is KQE20160512109

[Jammy]

Hi,
Sorry for the trouble caused.
Could you please first tell us if you used the original power cable or the one came with the unit?
Please confirm if the head unit will turn off automatically when you pull out the ignition key.
Regards

[mr_p_pkight]

Since the original cable has a quadlock connector that is what I used. I will have to check the behaviour with the key.