Spend some money - Dometic portable power

[ndubes]

Originally Posted by Kibo

Isn't that called a CRT-D? Or am I missing something?

Exactly, but CRTD requires a different set of components ($) and bigger size. That's all to say it's putting together a jump starter with a battery backup is completely doable they've just decided not to package them together probably for those reasons - size and cost. Someone's bound to at some point though.

[Kibo]

Ah, gotcha. I tried to figure out a way to integrate jumpstart capability into my homebrew Lithium battery setup and ultimately decided against it. It's far easier (and less expensive) to buy a Lithium jump-pack.

When I was looking at Goal Zero a year ago, one of the dealbreakers for me was not being able to charge the battery from the vehicle's 12V system. It looks like Dometic has a 12V input, but it's certainly not sized to handle much current based on the size--then again, this is only a 40Ah unit.

Edit: looks like the 12V input is 8A. Pretty sweet little unit, aside from the price!

[ndubes]

I agree, the lithium jump-packs out there have gotten pretty reasonable and are already ultra compact. Maybe having two separate units isn't a bad thing, might even be easier on storage really.

[Kibo]

Just make sure to test it ahead of when you need it. I discovered the hard way that the voltage detection safety features of the jumper clips that came with the first Li jumper I bought wouldn't let the jumper connect to a battery--even one that's fully charged! Thankfully the clips are easily replaced, but it made for an inconvenient musical-cars scenario on a wintry worknight.