Marmot Lithium MemBrain Review

Likes

The Marmot Lithium Membrain is an improved version of the company's Lithium sleeping bag. A waterproof-breathable shell material makes it better able to resist frosty condensation, snow and ice, and also and makes it more durable. This is Marmot's best zero degree bag and one of two tested with a waterproof shell material.

The Lithium is stuffed with 28 ounces of top quality 850+ fill down. We believe it's the warmest of all the zero degree bags tested here. The cut is quite average, with 62/58/40 shoulder, hip, foot girths, and accommodates a variety of body types.

One well-designed part of this bag is the hood pull cord, which remains comfortable even fully cinched. Most other sleeping bags place the cord on the outside edge of the hood (it's easier and cheaper), but this is uncomfortable when the hood is fully cinched because the tight cord smashes up against your face. Marmot does a great job addressing this problem. Of the 30-plus sleeping bags we tested, the Lithium has the second most comfortable hood (Mountain Hardwear's Phantom takes first place).

Dislikes

While the Lithium Membrain is constructed with excellent materials, its design lacks a basic feature found on all other bags: a Velcro strip that connects the two parts of the neck baffle. Without this, the neck baffle is essentially useless. There's a drawcord, but without a closure you cannot cinch the baffle tight around your neck. This renders the baffle ineffective at trapping hot air. And, in our opinion, this is a glaring oversight. Consequently the bag is slightly less warm and considerably less comfortable.

At 46 ounces, the Lithium Membrin is the second heaviest heaviest of the cold weather bags reviewed here. There are three reasons for this: 1) 28 ounces of down; 2) a heavier and more durable shell material; and 3) a poorly designed neck baffle. The bag is 3.18 ounces heavier than the average weight of the bags tested in this class. It's also slightly warmer than the average but the difference, matched against the bad neck baffle, isn't enough to warrant a better rating.

This is a very good sleeping bag. It will keep you toasty on frigid and foul nights. But there are other sleeping bags that offer higher performance at the same or lower price.

Best Application

Mountaineering, alpine climbing, backcountry skiing.

Value