Injector Pulse Width vs Battery Voltage

Today I have mostly been looking at injector pulse width against battery voltage for the OEM ECU.
It looks like the ECU uses it's 'base' pulse width when the battery voltage is above 16.5V
Below 16.5V the ECU increases the pulse width as the voltage decreases.

Here's the raw data I measured (voltage,pulse width increase in ms):

5, 3.262

6, 3.262

7, 2.912

8, 2.167

9, 1.555

10, 1.156

11, 0.779

12, 0.516

13, 0.357

14, 0.24

15, 0.132

16, 0.048

17, 0

18, 0

19, 0

I also noticed that whilst the ignition advance doesn't appear to be affected by battery voltage, the ignition dwell time is and increases at battery voltage falls.

Ignition During Cranking

Had a quick look at what happens during cranking today.
Couldn't see any affect on the injector outputs, but the ignition outputs were mildly interesting.

Here's one ignition output at 500 rpm normal running (upper trace is crank pulse, lower is ignition output):

And here it is again but with the cranking input driven high: