Topic
Nice chart for backpacking device power consumption
Forum Posting
A Membership is required to post in the forums. Login or become a member to post in the member forums!
Home › Forums › General Forums › General Lightweight Backpacking Discussion › Nice chart for backpacking device power consumption
- This topic has 8 replies, 8 voices, and was last updated 3 years, 8 months ago by Jerry Adams.
-
AuthorPosts
-
Jul 17, 2020 at 7:39 pm #3665016
nice chart from Backpacker Magazine on power consumption to help you determine what mah you’ll need via battery or solar. Source below:
Backpacker Magazine Apple News App: How to Power Your Electronic Devices in the Backcountry Ryan Wichelns
July 16, 2020; accessed 7/17/20Jul 17, 2020 at 10:06 pm #3665034What are the headings for the columns, or at least the heading for the last column, I’m not sure I understand what they’re saying in that last column.
Jul 17, 2020 at 10:42 pm #3665037I often double-check technical information published in Backpacker because I’ve found too many hiccups in the past. The pattern continues.
The third column in that chart seems to be an example of energy use / recharging patterns, not any kind of “average.” The author even states up front: “Consider how often your devices run out of juice with normal use.” The article doesn’t make that very clear for the chart.
I spot checked a few of the Wh (watt-hour) numbers in the chart against manufacturer specs and found some discrepancies. The article claims that most small batteries run at 3.7-3.8 volts, then goes on to use 3.6 volts across many devices. Bad assumption.
The Sony camera battery at full charge supplies 8.4 volts, which translates to 8.6 Wh stored – about 18% more than the 7.3 Wh shown, which seems to be based on 7.2 volts.
And all batteries require more energy to recharge than they store, due to inefficiencies like resistance in the wires and battery during charging. This lost energy varies from device to device.
For example, the Petzl headlamp battery needs 7.5 Wh (vs 4.5 Wh in the chart) to recharge via USB.
And the article recommends solar panels if a battery bank is insufficient. But many PCT thru-hikers mail solar panels home early in their trip. Most rely on battery banks with 37 Wh (“10,000 mAh”) to 74 Wh (“20,000 mAh”) of capacity and recharge those in town. Solar panels probably work best in base camps.
Yet the story describes a pretty good process for estimating battery recharge needs while hiking. Just confirm the numbers before you rely on them – preferably with actual measurements.
— Rex
Jul 18, 2020 at 5:18 am #3665048wow. Thank you. That’s really unfortunate that a chart can be published and yet be that far off. I wouldn’t have even thought to need to vet the data.
Jul 18, 2020 at 7:18 am #3665052There is something quite charming about this thread running concurrently with the thread about technology ruining the wilderness experience…grin
Jul 18, 2020 at 12:30 pm #3665090Yeah, it also coincides with my post for “Old Timers” on items we carry now that we did not carry ‘back in the day’ – like ’60s through the ’80s.
Lots of “really keen” tech stuff we now carry. But hey, I’m grateful for my SPOT beacon. It’s insurance whenI hike and hunt solo.
Jul 19, 2020 at 10:20 am #3665247Third column may be expected use per day (so charge needed per day).
https://www.backpacker.com/gear/how-to-power-your-electronic-devices-in-the-backcountry
see Rex already said same thing.
Jul 28, 2020 at 8:22 pm #3667141I gotta say, your phone should be in airplane mode while backpacking, and thus, use way less than 50% battery per day.
Jul 28, 2020 at 9:04 pm #3667148Last column, for example “charge 50% every day”, for 3110 mah device would require 1555 mah per day.
The only problem with this approach is it assumes I can figure what the percent charge required. Especially a phone can be variable.
Another approach would be to start out with a 10,000 mah battery and try it on a number of trips. If I frequently get close to using all the battery, then get a bigger one. If I never use even half the battery, get a smaller one.
I originally got a 10,000, then a 20,000, finally a 13,000 which is what i now use. I keep the others in the car. I often camp at the car so I can make sure and start backpack with everything fully charged. 13,000 is enough to last 5 nights.
Yeah, put it in airplane mode. Also, close all apps. Normally, apps in the background dont use battery but sometimes they do.
I listen to podcasts with bluetooth earbuds. That takes some more power. If I’m running low on battery, I’ll turn that off.
-
AuthorPosts
- You must be logged in to reply to this topic.
Forum Posting
A Membership is required to post in the forums. Login or become a member to post in the member forums!
Our Community Posts are Moderated
Backpacking Light community posts are moderated and here to foster helpful and positive discussions about lightweight backpacking. Please be mindful of our values and boundaries and review our Community Guidelines prior to posting.
Get the Newsletter
Gear Research & Discovery Tools
- Browse our curated Gear Shop
- See the latest Gear Deals and Sales
- Our Recommendations
- Search for Gear on Sale with the Gear Finder
- Used Gear Swap
- Member Gear Reviews and BPL Gear Review Articles
- Browse by Gear Type or Brand.