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Big Agnes Sentinel 30 Double Review

A mid-range double bag for weight-conscious and comfort-seeking adventure pairs
Big Agnes Sentinel 30 Double
Photo: Big Agnes
Best Buy Award
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Price:  $400 List | $399.95 at Backcountry
Compare prices at 2 resellers
Pros:  Spacious, decent warmth-to-weight ratio, reasonable price
Cons:  Bulky, ineffective hood closure, limited versatility
Manufacturer:   Big Agnes
By Jack Cramer ⋅ Review Editor  ⋅  Apr 30, 2021
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63
OVERALL
SCORE


RANKED
#17 of 21
  • Warmth - 20% 5
  • Weight - 20% 7
  • Comfort - 20% 7
  • Packed Size - 15% 8
  • Versatility - 15% 4
  • Features & Design - 10% 7

Our Verdict

Humans have been sharing body heat on cold nights for thousands of years. Ordinary one-person sleeping bags interfere with this classic method of conserving energy. Enter two-person sleeping bags, and specifically, the Big Agnes Sentinel. With this affordable model, you can stay light and fast on the trail while enjoying a roomier sleeping space at night that's more reminiscent of sleeping with a simple blanket like most people are used to. Although this isn't the lightest or most packable two-person sleep system, it stacks up well compared to other options at the same price point. Its biggest drawback might be its mediocre versatility. This bag requires two willing sleeping partners and also a pair of sleeping pads because the underside is uninsulated. Our testers were also frustrated with the functionality of the hood which was reluctant to stay snapped in place. However, we still think this bag is a great choice for long-term adventure partners and an affordable way to trim a few ounces from the group's overnight load.

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Price $399.95 at Backcountry
Compare at 2 sellers
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Pros Spacious, decent warmth-to-weight ratio, reasonable priceSpacious dimensions, super comfortable, great loft, lightweight, made in the USASuper lightweight, incredible loft, snag-proof zipper, cozy hoodBest-in-class warmth, legit draft collar, light weight, exceptional loftBest-in-class zipper, best-in-class hood, awesome loft, great warmth-to-weight ratio
Cons Bulky, ineffective hood closure, limited versatilityExpensive, awkward hood, good but not great zipperUncomfortably narrow dimensions, bare-bones design, noisy fabricReally pricey, kind of bulky, awkward hood closureNarrow leg dimensions, no draft collar, heavier and bulkier than some 3-season options
Bottom Line A comfortable, reasonably priced, two-person sleeping bagIf we could only have one bag for the rest of our lives, this would be itThe ideal bag when you need the warmth, but ounces matter tooThe best bag for the coldest shoulder season nightsExceptional warm and loft along with our favorite hood and zipper
Rating Categories Big Agnes Sentinel 30 Double MegaLite Hummingbird UL 30 UltraLite Swallow 20 YF
Warmth (20%)
5
8
8
10
9
Weight (20%)
7
8
9
7
7
Comfort (20%)
7
9
7
7
7
Packed Size (15%)
8
8
8
6
7
Versatility (15%)
4
7
8
8
8
Features & Design (10%)
7
7
7
7
7
Specs Big Agnes Sentinel... MegaLite Hummingbird UL 30 UltraLite Swallow 20 YF
Insulation 650 FP Down 850+ FP Down 950+ FP Down 850+ FP Down 900+ FP Down
Compressed Volume (L) 11.2 L 7.2 L 7.3 L 8.7 L 8.5 L
Measured Bag Weight (Size Long) 3.25 lbs (size regular) 1.62 lbs 1.45 lbs 1.86 lbs 1.94 lbs
Manufacturer claimed weight of size Regular (lbs) 3.5 lbs 1.5 lbs 1.33 lbs 1.81 lbs 1.79 lbs
Compression/Stuff Sack Weight (oz) 1.4 oz 1.6 oz 0.8 oz 1.6 oz 1.0 oz
Hydrophobic down Yes No No No No
Manufacturer Temp Rating (F) 30 F 30 F 30 F 20 F 20 F
EN Temp Rating (Lower Limit, F) Not rated Not rated Not rated Not rated Not rated
Fill Weight (oz) 19.5 oz 13 oz 12 oz 17 oz 17.5 oz
Compression or stuff sack included? Stuff sack Stuff Stuff Stuff Stuff
Shell material Polyester ripstop Extremelite (12D) Pertex Endurance (10D) Extremelite (12D) Pertex YFuse (20D)
DWR? Yes No Yes No No
Liner material Polyester taffeta n/a n/a n/a Pertex 20 denier nylon taffeta
Neck Baffle Yes No No Yes No
Small Organization Pocket No No No No No
Zipper Dual 3/4-length Full-length / Side Full-length / Side Full-length / Side Full-length / Side
Shoulder Girth (in) 105 64 58 59 60
Hip Girth (in) 105 Not stated 52 Not stated 56
Foot Girth (in) 84 39 38 38 38

Our Analysis and Test Results

There are plenty of budget double sleeping bags that are ideal for car camp or short trips near the trailhead. It's much harder to find an affordable two-person bag that's suitable for backpacking. The Sentinel is our favorite model that fills this niche. Higher-end double sleeping bags are certainly available, but this one is our top choice for any seeking a bargain for snuggle-filled, backcountry overnights.

Performance Comparison


Double sleeping bags come the closest of any zippered sleeping bags...
Double sleeping bags come the closest of any zippered sleeping bags to approximating the feel of snoozing with an ordinary blanket.
Photo: Jack Cramer

Warmth


When it comes to temperature ratings for two-person sleeping bags, you usually have to take the manufacturer at their word. The Sentinel does not receive a standardized EN temp rating but Big Agnes assigns it their own 30F rating. This seemed to be overly optimistic in our tests. The 19.5 oz of 650FP feels like it's plenty lofty to achieve this rating, but the design has other issues that compromise its warmth. These start with an unreliable hood closure and meager neck baffle that are fairly ineffective at sealing heat inside. The underside of the bag is also uninsulated so our testers observed highly variable levels of warmth depending on the sleeping pads that they used. The system to attach pads to this underside was also frustrating.


We think experienced backpackers may be able to employ enough tricks to enjoy this bag down to its advertised temp rating, but beginners or anyone who seeks a bag that easily meets its temp rating should temper their expectations with the Sentinel.

The underside of the Big Agnes Sentinel is uninsulated so its...
The underside of the Big Agnes Sentinel is uninsulated so its necessary to use a pair of good sleeping pads.
Photo: Jack Cramer

Weight


The Sentinel 30 might not set any records for low weight. On our scale, a size Regular weighed in at 3.25 lbs. In hand, that even makes it feel like a hefty package. But its overall weight equates to just 1.63 lbs per sleeper, which is lighter than even some premium single-person sleeping bags. It's also considerably lighter than comparable two-person sleeping systems at the Sentinel's lower price point. Among budget double sleeping bags, it's the lightest option that we're aware of.


Two-person sleeping bags often provide impressive roominess, as seen...
Two-person sleeping bags often provide impressive roominess, as seen here with these two sets of feet and substantial space between them in the Big Agnes Sentinel.
Photo: Jack Cramer

Comfort


One of the biggest benefits of a two-person sleeping bag is that it supplies roomier interior dimensions to both sleepers. With 105" of shoulder and waist girth, this bag should provide ample space for everyone inside, even if one of them happens to be a bed hog.


The experience of a double-wide sleeping bag is also much more akin to using an ordinary blanket than a restrictive mummy sleeping bag. This can be a welcomed difference among only occasional backpackers. Our testers also raved about the polyester taffeta lining fabric. It proved to be soft and cozy without any of the annoying crinkling sounds that can sometimes accompany ultralight fabrics.

The simple drawstring stuff sack that's included with the Sentinel...
The simple drawstring stuff sack that's included with the Sentinel 30 is pretty ineffective at compressing the bag fully.
Photo: Jack Cramer

Packed Size


All double bags will show certain drawbacks in the packed size department. In a third-party compression sack, we measured this behemoth at 11.2 liters. Although that equates to a respectable 5.6 liters per person, it can be difficult for one person to fit the combined volume of the whole bag into their backpack. With proper coordination and sharing some of the other group gear, it's simple enough to mitigate this issue. However, one person should be prepared to have a substantial portion of their pack occupied by this sleeping bag.


Another issue is that this bag only comes with a simple drawstring stuff sack that proved to be ineffective at compressing the bag. It was even worse than most stuff sacks, with a substantial section of excess fabric leftover with the bag stuffed inside. To pack this sleeping bag as small as possible, we suggest investing in a sturdy after-market compression sack.

One of the few versatility advantages of a two-person sleeping bag...
One of the few versatility advantages of a two-person sleeping bag is that they're easier to share on a cold morning.
Photo: Jack Cramer

Versatility


The Achilles heel of a two-person sleeping bag is probably their limited versatility. They're too heavy and bulky for single-person use, so they're only viable when you have two willing sleeping partners. This can be an issue if you don't have a regular adventure partner, or if your plans blow up and someone must cancel last minute. Most folks will want a single-person bag in addition to having a double bag.


The Sentinel 30 also specifically suffers from an ineffective hood closure that invites drafts on cold nights. This shrinks the usable temperature range of a bag whose insulation might otherwise allow it to stay functional down to considerably lower temps. The underside of the Sentinel is uninsulated so it must be paired with good sleeping pads if you hope to be warm down to its manufacturer 30F temp rating. Collectively all of these issues leave the Sentinel with a disappointing level of versatility.

We're big fans of the Y-shaped zipper slide on this bag because it...
We're big fans of the Y-shaped zipper slide on this bag because it helps reduce snags.
Photo: Jack Cramer

Features & Design


Big Agnes includes an impressive feature set on the Sentinel 30. This bag is fitted with separate sleeves for securing your sleeping pad and camp pillow. Some of our seasoned testers believed that these features were unnecessary, but others acknowledged that they helped the Sentinel achieve a closer feeling to sleeping at home with an ordinary blanket. The neck baffle is even sewn closed at the corner of the bag to create a shallow pocket that accepts a hand and lets you nestle in even deeper.


This bag is fitted with two-way, 3/4-length zippers on either side. This allows both sleepers to adjust their venting and stay comfortable in a variety of conditions. The Y-shaped zipper slide also proved to be effective at reducing snags. Unfortunately, the Sentinel doesn't include any organizational pockets for storing a headlamp or smartphone, but this is pretty much the only feature it doesn't have.

In addition to some straps to attach your sleeping pad, there is...
In addition to some straps to attach your sleeping pad, there is also a sleeve to secure a camp pillow.
Photo: Jack Cramer

Value


The inclusion of the Sentinel 30 in our budget backpacking sleeping bag category might raise some eyebrows because it retails for twice as much as many of the other bags in the review. The total cost might be hard to stomach, but we still think it's affordable if you go by the adjusted cost per person. With this adjustment, this bag offers one of the lightest two-person sleeping systems at a budget price point. In fact, the cost to achieve similar warmth and weight with two separate single-person bags would be substantially higher. That's why we consider the Sentinel to be an awesome value and an option that should be on any budget-conscious shopper's radar.

Conclusion


Two-person sleeping bags will always come with some versatility disadvantages. However, if you have a reliable backcountry partner who is willing to share a bag, double sleeping bags can offer considerable advantages in terms of weight savings and roominess. The Big Agnes Sentinel 30 supplies these benefits at a reasonable price. That's why it's over favorite bargain sleeping bag for pairs of backcountry travelers.

Jack Cramer