Phantom,
Interesting find. While it would be possible to charge from this product, it would only get you about a 25% charge at best. It's a 12V / 60Ah Sealed Lead Acid battery => 12V x 60Ah = 720 Wh (Watt-hours). The Enertia's battery is 3,100 Wh (Watt-hours) or 3.1 kWh.
So... you'd need five of them to get a full charge! You'd basically be shuffling energy from one battery pack to another, so probably not so efficient. Good thought though... and maybe still enough to go on a AAA "rescue" truck to get you enough charge to get to an outlet if you're stranded.