I've had relatively limited experience with different vehicles in this regard, so thought I'd reach out to you all.
On my car, my mom's XC70, and my dad's old S40, all noncritical electrical items (lights, climate control, aux 12V sockets, etc) are shut down while the engine cranks. This makes sense as these systems can use in excess of 40 amps, and turning them off makes that much more cranking current available to the starter. Downside is anything running on accessory power will shut down and restart after the engine cranks. Dashcam works fine with internal battery, but my custom gauge with data logger needed a hefty capacitor bank and regulator to stay on when starting.
However, on my dad's Subaru Crosstrek, essentially all loads remain energized. That combined with a smaller battery means the little 2L boxer cranks over much slower with noticeable strain in the cold compared to the larger Volvo engines despite the Crosstrek using 0w-20 oil and the Volvos using 5w- or 10w-30.
Do your vehicles automatically shut off accessories while cranking, or leave them on and rely on the battery to deal with the extra load? Do you manually turn off items before cranking on very cold days or when you suspect a weak battery to squeeze out some more CCA?
On my car, my mom's XC70, and my dad's old S40, all noncritical electrical items (lights, climate control, aux 12V sockets, etc) are shut down while the engine cranks. This makes sense as these systems can use in excess of 40 amps, and turning them off makes that much more cranking current available to the starter. Downside is anything running on accessory power will shut down and restart after the engine cranks. Dashcam works fine with internal battery, but my custom gauge with data logger needed a hefty capacitor bank and regulator to stay on when starting.
However, on my dad's Subaru Crosstrek, essentially all loads remain energized. That combined with a smaller battery means the little 2L boxer cranks over much slower with noticeable strain in the cold compared to the larger Volvo engines despite the Crosstrek using 0w-20 oil and the Volvos using 5w- or 10w-30.
Do your vehicles automatically shut off accessories while cranking, or leave them on and rely on the battery to deal with the extra load? Do you manually turn off items before cranking on very cold days or when you suspect a weak battery to squeeze out some more CCA?