One big problem not yet mentioned is STABILITY of the power source. Most '12 VDC' ham expect to see 11.5 to 15 volts and will reset their innards if the voltage ever drops below 11, such as when you key the transmitter each time.
Like many others, I have migrated to LiFePO4 technology. OK, they aren’t cheap, but these batteries are much better than lead acid. I run a 100 Watt transceiver and a 15.6” laptop for logging. With a 68 Ah battery I can easily operate for 6 hours in contests.
I boost the Voltage to a rock solid 13.8 using an MFJ 4416C, which was originally bought to use with an AGM (lead acid) battery. The laptop is run from the battery via a 12 Volt to 19 Volt “car” adapter, even though the laptop can run around 8 hours from it’s own internal battery.
Beware, a laptop can draw quite a lot of current, around 5 Amps, while charging the internal battery.
73 Dave