REASONS TO BUY
Warm
Comfortable hood
Ultra light shell fabric
REASONS TO AVOID
Neck baffle integrated with zipper baffle (not a true neck baffle)
Low weather resistance
Marmot Lithium Review
An excellent choice for cold weather sleeping in dry conditions
Credit: Marmot
RELATED: Best Winter Sleeping Bags
Our Verdict
The Marmot Lithium is a bag for those who bivy less or if going lightweight is a higher priority. Overall, the Lithium is one of the warmest we tested in our Cold Weather Down Sleeping Bag Review, even without a dedicated neck baffle. It is not the most weather-resistant. We feel this bag is a great match for a backpacker who likes to use a lightweight waterproof shelter. This way you can enjoy the weight savings without worrying about getting wet.
Editor's Note: We updated this review on May 5, 2023, to share information on updates to the Lithium bag.
Compare to Similar Products
 This Product
Marmot Lithium | |||||
|---|---|---|---|---|---|
| Awards |  Best Simple Design with Weather-Resistance | Best for Fast and Light Winter Camping |  Best Bang for Your Buck | ||
| Price | $579.00 at REI Compare at 2 sellers | $600 List | $680 List $669.99 at Backcountry | $325.00 at REI Compare at 2 sellers | $315.81 at Amazon Compare at 2 sellers |
Overall Score  |
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| Star Rating | |||||
| Bottom Line | If you sleep in a tent to keep your bag dry, this is the one for you | This lightweight sleeping bag comfortably cradles you with warm, lofty down | Excellent for moving in the mountains in cold weather, this model is lightweight, packs small, and stays true to its temperature rating | This budget bag offers protection from the elements via a large draft tube and plush draft collar | For those who expect to sit out a storm and play cards or want an inexpensive throw bag for car camping, this is an economical option |
| Rating Categories | Marmot Lithium | The North Face Infe... | Mountain Hardwear P... | Mountain Hardwear B... | Marmot Never Summer 0 |
| Warmth (20%) | |||||
| Weight (20%) | |||||
| Comfort (20%) | |||||
| Packed Size (15%) | |||||
| Weather Resistance (15%) | |||||
| Features (10%) | |||||
| Specs | Marmot Lithium | The North Face Infe... | Mountain Hardwear P... | Mountain Hardwear B... | Marmot Never Summer 0 |
| Measured Weight (size Regular) | 2.90 lbs | 2.68 lbs | 2.68 lbs | 3.13 lbs | 3.19 lbs |
| Fill Weight | 27.8 oz | 29 oz | 29.6 oz | 35.0 oz | 36.2 oz |
| Type of Down Fill | Goose Down | Down RDS Certified | Goose Down RDS Cert/Fluorine Free | Down | Down |
| Fill Power | 800+ | 800 | 850 | 650 | 650 |
| Material Weight (excludes down filling) | 14.1 oz | 13.9 oz | 13.3 oz | 15.1 oz | 14.9 oz |
| Temperature Rating | 0°F | 0°F | 0°F | 0°F | 0°F |
| Yes | No | Yes | Yes | Yes | |
| Shoulder Girth | 61" | 64" | 58" | 62" | 62" |
| Hip Girth | 56" | 60" | 52" | 53" | 57" |
| Foot Girth | 42" | 44" | Not listed | Not listed | 48.5" |
| Shell Material | Pertex 20D 100% nylon ripstop | 15D recycled nylon, 30D nylon taffeta | 10D Nylon Ghost ripstop, DWR finish | 20-Denier ripstop nylon | 20-Denier ripstop nylon |
| Continuous Baffle | No | Not listed | No | Yes | Yes |
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Our Analysis and Test Results
The Lithium we tested is shown on the left, followed by the updated Lithium on the right.
Lithium Updated
Marmot updated the Lithium bag with their ExpeDry water repellent technology, which is designed to protect against moisture and decrease drying time if your bag gets wet. We're linking to the updated bag, but the remainder of our review pertains to the previous model.
Marmot updated the Lithium bag with their ExpeDry water repellent technology, which is designed to protect against moisture and decrease drying time if your bag gets wet. We're linking to the updated bag, but the remainder of our review pertains to the previous model.
This is a seriously warm bag packed with high quality 800+ fill down. It does not have a waterproof fabric or treated down. So this is a traditional style sleeping bag that belongs in a tent rather than a snow cave or bivy under a tarp during the winter months. With that said, it packs in a solid amount of warmth for being only 2lbs 9oz. This bag also packs quite small, and this is due to the lack of a few features, as well as a thought-out minimalist design from the start.
Performance Comparison
The Marmot Lithium 0F lofts extrmely quickly and is as light as a feather. If you are sleeping in a 4 season tent and do not touch the tent walls, the ultralight fabric is perfect.
Credit: Jeff Rogers
Warmth
Sleeping in the Marmot Lithium is a great experience. The bag kept each tester warm and the hood was plenty comfortable. We did notice that the zipper baffle and neck baffle were integrated into one. This is clearly a weight savings measure and did not insulate as well as two dedicated zipper and neck baffles. Another thing to note on warmth is the existence of a second left-hand side zipper. The idea behind the second zipper is to allow you to do tasks while still in the bag. However, if the secondary zipper baffle is not laid flat against it, cold will seep in. Our testers only experienced this once in a handful of nights sleeping out.
Weight
The Marmot Lithium weighs in at 2lb 9oz on our scales. This is quite the low weight for a 0F sleeping bag and is a credit to the bag's ultra-light face fabric and minimalist baffle design. In fact, when we were taking pictures of this bag on a windy summit, the bag almost flew away! Marmot includes a stuff sack that is ultralight material as well. Overall, this bag is light enough for any human-powered cold weather mountain excursion.
Here we are trying to get a side profile photo of the marmot lithium to show its loft, a slight gust of wind picks it up! You can see how truly light the fabric and materials of this bag are. Don't worry, it didn't blow completely away!
Credit: Jeff Rogers
Comfort
This is where the bag really shines. It blends a slightly tighter cut and a feature set that allows you to be more comfortable while in the tent. The second zipper can be undone, and you can sit in the bag with both of your arms out and your upper body (and even head if you want) inside the bag. This allows you to do all of the different tasks in the AM while still cocooned in fatty goose down. Brew up, pack up and then emerge from the sleeping bag ready to move. The comfort this bag provided was excellent was catching some sleep too, we just wish it had a dedicated neck baffle as well.
Packed Size
The Lithium is a very compact sleeping bag when packed. Either just stuffing it first into your pack or using a compression sack, the bag easily fits into our testers 45L ski pack for an overnight.
We compressed this bag as much as we could, and it stuffs down to a very pack-friendly size
Credit: Jeff Rogers
Features
Again, the feature set on this bag is excellent. The second zipper that allows you to stay in the bag and still do camp chores is a welcome addition. It also features a small zippered pocket for storing small items while you sleep. The hood is one of the best we tested, and easily swallowed up the smallest grapefruits and largest watermelon heads among the tester group. This allowed everyone to really maximize the warmth of the bag, and it ranks highly among our features metric because of this. What detracts from the bag is the lack of a dedicated upper neck baffle. This slightly reduced warmth as well.
Tester Marina Shirokova testing out the bag's comfortable hood.
Credit: Jeff Rogers
The Lithium can seal up very tight, one of our favorites features of this bag.
Credit: Jeff Rogers
Weather Resistance
The Lithium is not a bag you want to sleep out in the open with, especially if there is significant precipitation in the forecast. We love this bag for any time we use a dedicated winter tent or full coverage tarp system. With that said, it has a very effective DWR and works well to shed light moisture. The Pertex Quantum that makes up the shell fabric is 20d, which is a bit heavier than some ultralight bags and is indeed windproof. With such a great face seal, you can get by in windier pyramid tents and such without much hassle.
Marmot Lithium Membrain Hood
Credit: Max Neale
Value
A quality bag, the Lithium is a great value. It's ideal for winter camping and packs extremely small. If you find yourself venturing into really cold temps, there are better values out there, but in the Rockies, it provides plenty of warmth and a great feature set for the money.
Conclusion
The Marmot Lithium is an excellent bag for winter camping. It has a slightly tight cut and second zipper which allows you to stay in the bag while doing AM camp chores. The lack of a dedicated neck baffle did reduce its warmth metrics, but with such a perfectly executed hood, it still scored high marks in comfort and features. Buy this bag if you frequently camp in a tent while overnighting.
Marmot includes a nice storage sack with this bag
Credit: Jeff Rogers
—Jeff Rogers
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