Elle on Wheels wrote:

---

It's sounds as if it would be a good idea to have a 2nd house battery to run computers and phones and other appliances so that the main battery can be reserved for the lights and essentials....

---

 I'd suggest a "wait and see" on this one. check the comments about charging a laptop from the car while on the move, also your phone, but phones don't draw down much anyway.

Be economic with your use of 12v power, don't leave lights on when you don't need them. (LED lights are very economical in the use of power.)  Don't leave a TV going when you're not watching it. Avoid using an inverter if there is another way, If using an inverter for any reason make sure that the inverter itself is switched off when not being used.

I have a "1900 amp" jumpstarter that I use as a backup for my house or aux battery (Techie types please note my use of quotes around the term "1900 amp" before hijacking the thread into the area of the real capacity of these jumpstarters) I have also used it to power a TV when camping away from ground power but at the time my house battery was "on its last legs"