Hi,

I have a new Erisin android6, 2-din, 7" head unit. Pretty generic.... Flattened the battery in a few days.
The options for power-down time after ignition off are something like:

none
10 min
30min
60min

BUT a nasty flaw: "None" blanks the screen but does NOT power down, ever...
It takes about 700mA, which will not be good for your battery. Ensure this (default) setting is altered.
This may be the cause of the flurry of complaints about flat batteries.

Luckily the "10min" setting cuts the power drain to 300mA for 10 mins then cuts the power completely. Its what I use now.
I imagine the 30&60min settings do much the same.

Note that the "ignition/switched" (red) +12V supply only takes 30mA and is clearly just a sensing line and almost all the power goes via the "unswitched" yellow lead.

I hope some people find this useful.

Also when fitting I found it easier and neater to buy some new plugs, cut off the existing ones making it trivial to thread through holes and then remake the plugs when in the back of the fascia.
https://www.ebay.co.uk/itm/10Pcs-Connector-SMA-Male-Plug-Crimp-RG174-RG316-LMR100-Cable-Straight/252158507404?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

I found putting the GPS antenna externally was better rather than using the magnet to attach it to the top of the radio case, although this does work quite well.

The supplied flat wifi aerial does not work well stuck to the top of the radio, it works much better stuck to the dash (remake connector for this).

I hope someone finds this useful.