Back in January of this year we took a sneak peek at three new Yeti Lithium Power Stations from Goal Zero, which promised a bevy of upgrades over the company’s previous line of solar generators. At the time, Goal Zero indicated that we could expect the first two models — the Yeti 400 Lithium and the Buy Now  — to begin shipping in the first quarter of the year, and true to their word both began arriving on store shelves earlier this week. How exactly do these products improve on their predecessors? Let’s take a look.

When designing this new generation of power station, Goal Zero decided to make the jump from lead-acid batteries to Lithium energy cells. This proved to be a wise move for a number of reasons, not the least of which was weight savings. The older Buy Now  model, which used lead-acid batteries, tipped the scales at a hefty 103 pounds.

In comparison, the new Yeti 1400 Lithium is a relatively svelte 45.7 pounds while at the same time incorporating a higher capacity battery. The Yeti 400 Lithium doesn’t see a dramatic improvement over its previous-generation counterpart, but it still manages to shave 12 pounds off its weight, slimming down to a very reasonable 17 pounds.

In addition to being much lighter, the lithium batteries also have a shelf life that is twice as long as lead-acid, allowing them to maintain a charge for longer periods of time when not in use. The lithium cells are also better equipped to handle devices with a higher energy draw, allowing the new Yeti Lithium Power Stations to power higher-capacity devices for much longer periods of time, including electric tools, television sets, and even a small refrigerator.

As with Goal Zero’s previous generators, the new Lithium Power Stations can be charged using AC wall outlets, DC ports in a car, or the company’s popular line of solar panels. Additionally, a new LCD display provides more information to the user as well, including current charge levels, the speed at which the generator is being depleted or recharged, and an estimate of the run time of devices that are plugged into it. The generators also come with better surge protection that allows them to dispense power more efficiently to those devices as well.

The Yeti 400 Lithium and Yeti 1400 Lithium are available now for $700 and $2,000, respectively. Visit goalzero.com for more information.