weak battery.

[mitzi1]

My ute has a battery with a residual charge after standing overnight or even about 5 to 6 hours of 12.3 V. Could this affect the reading of the maf sensor when starting before alternator raises the charge again.
Any advice appreciated.

[DaveXT]

Probably not, but your Battery may at least need a charge if it doesn't get driven much or a new Battery at worst.

[DibbyDibbyDJ]

12.6 -12.9 is fully charged. so you are just under.

The ECU has capacitors inside which are used to power the electronics, rather than straight from battery. This is known as your system voltage, and will not be affected by 12.3 v on a cold start as these capacitors are charged up when vehicle awakes

[mitzi1]

Thanks for that mate. A really informative answer, and thanks again. Got something to go on now.