Reviews > Lighting > Lanterns > Brunton Liberty Mantleless Lantern > David Sowards-Emmerd > Long Term Report

Long Term Report - Brunton Liberty Mantleless Lantern
September 6, 2005

Backpacking Background:
I began backpacking semi-frequently about four years ago, soon after moving to California. I generally take weekend (1 night) trips, and occasionally take 3-4 day trips. Most of my backpacking is at moderate altitude, 6,000'-12,000' (1,800-3,650 m), in conditions ranging from dry desert to hail/heavy snow in the mountains. In winter and spring, I split time between Southern California (SoCal) deserts and snowshoeing/skiing/snowcamping in the Sierra/Cascades. Summer and fall I tend to stick to the high country. I have reduced my packweight down to less than 50 lb (23 kg) over the past year - including food/water and a bear barrel. I'm trying to include more mountaineering, climbing and bouldering in my trips.

The Liberty Lantern arrived on March 1, 2005.

Product Description:

Manufacturer's Specifications:
"# 4'' x 2.5'' x 1.3'' (10.2 cm x 6.4 cm x 3.3 cm)
# 8.3 oz (235 g)
# Fuel: Isobutane
# Rating: Approximately 80 watts / 30 candlepower
# Burn time: Up to 6 hours at high output (one 8 oz canister)
# Platinum element instead of traditional mantles
# No fragile glass or plastic components
# Piezo electric ignition
# Built-in reflectors aim the light exactly where you need it
# Includes durable nylon case
# Limited lifetime warranty"

Specifications (as measured by me):
Weight (Lantern only): 7.1 oz / 200 g
Weight (Case): 2.1 oz / 58 g
Dimensions of Case: 5.12'' x 2.75'' x 2'' (13 cm x 7 cm x 5 cm)
Dimensions of Lantern (folded): 4.25'' x 2'' x 1.25' (10.8 cm x 5 cm x 3.2 cm)

Product Description:
The Liberty is a compact, canister-fueled lantern that produces light with a platinum catalyst (similar to a Jon-e handwarmer). For a more detailed description of the lantern, see my Initial Report

Field Testing:

For details on my first two months use of the lantern, see my Field Report.

Continued Field Testing:

Since the Field Testing period, I've used the lantern on several more backpacking and car camping trips as well as around the apartment and when on vacation.

I used the lantern briefly on a Memorial Day weekend car camping trip at Lava Beds National Monument - the lantern was all but useless next to a 2 mantle lantern a member of our group brought along, so it didn't see much use.

While visiting family and in-laws in northern Michigan (low elevation and hot) in early July, I used the lantern quite a bit. In addition to generic use and seeing how few bugs the lantern attracted, I used the lantern to help light up a late evening dinner on the patio, but the light produced by the lantern was comparable to the light produced by the three single-wick citronella candles on the table (and the lantern flared up several times). I also used the lantern to read in my Integral Designs Bug Liner (mesh bug tent) by placing the lantern outside the tent. This worked okay, but I had to hold the book at an angle since the light wasn't shining 'down' on it, but was coming from the side. Finally, I decided to try night kayaking on Lake Michigan one night, and left the lantern glowing on the shore as a beacon so I could find my way back to the correct spot on shore (see photo below showing the lantern in the distance - orange jagged line due to camera shake).

I also used the lantern around camp on three backpacking trips in and around Yosemite National Park: Smith Peak (Hetch Hetchy area), Lyell Canyon (Tuolomne area), and Gem Lake (Emigrant Wilderness in Stanislaus National Forest). These spots were all around 8,000' (2,400 m) elevation and temperatures ranged from 40-50 F (4-10 C) when I used the lantern. On the last two of these trips, the lantern supplemented campfires in lighting up other areas of camp and areas not illuminated by the fire. On all three trips, I was using my mesh bug tent, and used the lantern (and occasionally a headlamp) for setting up my sleeping arrangements and for a bit of reading in the tent. The down side is that when I'm ready to go to sleep, I have to get out of bed and reach outside the tent to turn the lantern off. For all the tasks I used the lantern for during this trip, a headlamp was much more suited to the task. Below is a photo of the lantern at my campsite on top of Smith Peak.

Variability of Light Output:
I believe I've observed differences in light output on two timescales. First, the output varies from second to second in colder weather and/or at moderate altitude, similar to the way a canister or white gas stove flickers. Second, the light seems to vary considerably from trip to trip, which is probably due to different conditions as well as different types and sizes of fuel canisters as well as the actual amount of fuel remaining.

Heat Output:
Since the lantern puts out so much heat, I figured it could easily boil water. So I tried this out. I set up a folding grill above the lantern, put a pot of water on top and turned it on. No luck on this trial, the temp only reached 155 F (68 C), which I guessed was due to the large ,~2'' (5 cm), spacing between the top of the lantern (not the element, but the actual metal top part of the lantern). Since the gap between a pot and stove is typically much smaller than this, I tried again, with about a 0.5'' (1.2 cm) gap. This time, the 8 oz (.24 l) of water came to a boil in just over three and a half minutes, showing this lantern puts out a considerable amount of heat! I should note that I also used aluminum foil as a heat shield between the lantern and the canister. Below is a photo of the setup.

Ignition:
With warmer temperatures, I have not had any more trouble igniting the lantern with just the piezo sparker.

Flare-ups:
I continued to observe flare-ups even at low elevations and warmer temperatures. These did not only occur around startup, but once occurred after the lantern had been running for 15 minutes or so.

Light Spread and Leakage:
As stated in my Field Report, the mirrors allow a bit of adjustment in the beam pattern. However, a considerable amount of light leaks out the back - between the mirrors and the central metal protector - and much more light is lost upwards. This lantern would be much more useful to me if all this lost light could be pointed forward and down, but heat production and dissipation is claimed to be a problem with this by the manufacturer. Below is a photo of the lantern from above, showing the light leakage behind the lantern, as well as the spread of the light produced by the lantern.

Bugs and the Lantern:
I haven't had much of a problem with bugs swarming around the lantern at all. I did have one mosquito land on the face of one mirror, and he was quickly toasted.

Durability:
I've dropped the lantern several times, both when attached to a canister and when trying to attach it to a canister with cold hands. Only minor damage was incurred on one occasion, and I was able to bend the mirrors back into place by hand. Minimal mirror scratching/melting occurred during the testing period.

Fuel Efficiency:
I didn't take the plunge from white gas to canister stoves until about a year ago, and the only reason I did so was convenience, as the fuel canisters are expensive and non-refillable (read: landfill friendly). If the lantern were to put out something in the ballpark of the claimed 80 watts, then I wouldn't mind paying for the canisters so much. However, I can get much more light out of a flashlight of comparable weight. Additionally, using rechargeable batteries is both cheaper and more environementally friendly than using canisters. This combined with the heat production issues (not supposed to use in tent, etc.) and claimed 6 hours runtime for a $4-5 canister mean I will probably not continue to use this lantern in the future and will opt for a flashlight or headlamp instead.

Things I like:

• It's just a really cool toy!
• Well built.
• Easy to ignite and adjust to a nice glow.
• The secondary, lower rubber gasket is a nice idea as a backup against gas leaks.
• Nice for warming up cold hands.

Things I don't like:

• The light output is very misleading as it must refer to total output, not visible light output (lumens would be much more appropriate/useful)
• Color is very yellow/orange, very similar to a campfire glow.
• It's a bit fickle in the cold (flare-ups and oscillating output - similar to canister stoves at altitude).
• A large fraction of light escapes due to incomplete mirror coverage, much of this light is lost up
• Long cool down time means it typically gets left out overnight.
• Adjustment of the gas flow is VERY sensitive. The full range from off to full power is approximately 20 degrees (a full twist would be 360 degrees), thus it is extremely sensitive.

Finally, I'd like to reiterate that my main complaint with this lantern is the very low visible light output compared with 80 watts claimed by the manufacturer. I find the output to be comparable to a 4 AAA cell ~2 watt halogen flashlight. I would definitely recommend anyone considering purchasing this lantern to try it out first to see just how much light is produced.

Suggestions for improvement:

• A larger reflector would be nice, especially one that could be detached to achieve a more uniform 360 degree lighting when desired.
• A less sensitive gas valve.
• A method to change the tilt of the lantern, so that more light can be pointed downward/towards the ground.
• Optional pot stand - why not boil water and produce light at the same time?

Future Use:

Reviews > Lighting > Lanterns > Brunton Liberty Mantleless Lantern > David Sowards-Emmerd > Long Term Report