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Using 18650 Batteries as a Lightweight Power Bank for Backpacking

18650 batteries as a power bank

As I talk about in my post about the best ultralight power banks for backpacking, one interesting solution is to bring 18650 batteries and use them as a power bank.   You just then need a charger which also has discharging capabilities so you can charge your phone and other USB devices with the 18650 batteries.  Here is how it works.


What Are 18650 Batteries?

Technically called cells and not batteries, 18650 batteries are rechargeable lithium-ion batteries.   They get their name because they measure 18mm x 65mm. Some newer 18650 batteries are actually a bit larger than this though.

Compared to standard rechargeable (NiMH-LSD) batteries, 18650 cells are much more power dense and thus lighter-weight. They also are also more efficient: in real-world situations, you are going to get more capacity with a 18650 than a NiMH-LSD battery.


18650 Batteries vs. Power Bank

Most power banks actually contain 18650 battery cells or other li-ion cells inside their casing. Thus, 18650 cells and power banks have a lot of similarities when it comes to performance.  However, there are some important differences when it comes to backpacking.

Here’s how the pros/cons break down.


Pros of 18650 Batteries for Backpacking

Modular Solution

This is by far the biggest benefit of using 18650 batteries backpacking.  The entire setup is very flexible. On weekend trips, you probably just need one 18650 cell.  On long thru-hikes or situations where you have high power needs, bring as many cells as you need.



Power banks have gotten incredibly lightweight.  The Anker 313, for example, has 10,000mAh of power at 7.52oz – which is 1,330mAh per ounce.

But it is still hard to beat the weight of a 18650 cell for ultralight backpacking.

A NiteCore 18650 3,500mAh cell weighs approximately 1.8oz.  Their LC10 charger weighs just under 1 oz.  There are other chargers with discharging capabilities, but the LC10 is the lightest I’ve seen.

Here’s how the weight breaks down:

  • 1 cell + charger (3,500mAh )= 2.8oz = 1,250mAh per oz
  • 2 cells + charger (7,000mAh) = 4.6oz = 1,521mAh per oz
  • 3 cells + charger (10,500mAh) = 6.4oz = 1,640mAh per oz
  • 4 cells + charger (14,000mAh) = 8.2oz = 1,707mAh per oz
  • 5 cells + charger (17,500mAh) = 10oz = 1,750mAh per oz
  • 6 cells + charger (21,000mAh) =11.8oz = 1,779mAh per oz

True, you do have to add in the weight of cables and a carrying case for the 18650 setup.  However, you can use silicone sleeves for the cells (which weigh almost nothing) and you’d have to bring cables for a power bank too.

*Note that this definitely isn’t the lightest setup when it comes to mAh per oz.  The NiteCore NB1000 Ultra Slim has 10,000mAh and weighs just 5.5oz – which is 1,887mAh per ounce.  But that powerbank doesn’t have the same flexibility as using 18650 cells.

nitecore lc10 charger

Shown: The LC10 charger/power bank by Nitecore. The charger weighs just 1oz.


Cells Are Replaceable

All types of batteries – including 18650 cells and power banks – will eventually lose storage capacity over time. However, with 18650 cells, you have the ability to replace them as it happens. You can just bring a new 18650 battery on your trip.

This isn’t possible with power banks.  The cells are soldered inside the pack.  Unless you know how to hack the power bank, you won’t be able to easily remove the cells.


Device Compatibility

If you switch your lighting to 18650 cells, you will only have to worry about one type of battery.   Yes, you could use a power bank to charge a USB headlamp – but you lose power when converting between different types of batteries.  In this sense, using 18650 cells as your power bank and lighting battery is the most efficient solution.


Downsides of Using 18650 Batteries for Backpacking

Charging Time

The biggest downside of using 18650 cells when backpacking is the recharging time.  They generally can only be charged at 0.5 to 1 amp input. By comparison, most good power banks recharge at 2.4 amps.  They also recharge all the cells in the power bank at the same time.  Unless you have a multi-slot charger (which will weigh more), you will have to charge each 18650 cell individually.

You generally need 3 to 6 hours to recharge one 3,500mAh 18650 cell.  By comparison, the Anker 6,7000 power bank will recharge in 3 hours.

This isn’t really a big deal when going on weekend backpacking trips.  But it is big drawback for thru-hikers who will you waste a lot of time sitting next to wall chargers in town.  Keep in mind that it is often difficult to even find an available wall outlet on popular hiking trails.



It is a lot easier to just bring a power bank with you when backpacking.  With 18650 cells, you’ll need to keep track of which cells are discharged, charging  times, and so forth.  There can also be a lot more parts with a 18650 setup, such as cables, cases and adapters.



18650 cells are pretty pricy.  Expect to pay $10 to $25 per cell depending on the capacity and features (some are high-performance, rated for cold-weather, etc.).  You’ll also need the charger, which is another $10-$30. By comparison, you can get an ultralight power bank for $20 to$60.


Learning Curve

The final drawback of 18650 batteries for backpacking is the learning curve.  It’s confusing as hell for newbies to figure out which type of 18650 cells to use, how to optimize the setup, how to daisy chain your flashlight and devices to charge them all at once…    It might not be worth researching all of this just to save an ounce or two from  your power setup.


Best 18650 Batteries and Charger/Power Banks

18650 batteries are expensive.  So, it’s no surprise that there are a lot of fake 18650 batteries out there.  These may work but have significantly reduced power capacity (you can tell because they will weigh less than real 18650 cells). Cheap 18650 cells also might not be protected and thus could spontaneously catch on fire (remember those Galaxy phones?).

The bottom line?  Don’t waste money on cheap knockoffs.   The same advice also applies to all types of batteries and power banks though.

Right now the best 18650 cells are made by NiteCore and Fenix. The 3,500mAh cells weigh approximately 1.76oz (50 grams).   Both brands make chargers with input/output, allowing them to work as power banks.

These are good 18650 chargers which also have output so they work as power banks:

*Use code RMN10 to get 10% off sitewide at the Fenix store*

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About the author /

Diane Vukovic grew up camping and backpacking in upstate New York. Now, she takes her own daughters on wilderness adventures so they can connect with nature and learn resiliency. With dozens of trips under her belt, Diane is an expert in minimalist camping, going lightweight, planning, and keeping her kids entertained without screens.

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  1. John Schmidt

    I have been using 18650 for longer backcountry trips to recharge my phone (for GPS navigation) as well as lighting. My problem is finding the right charging device.
    The Fenix ARE-X11 left too much energy in the battery
    The Nitecore F1 showed not functional (dead on arrival) and cost me the return postage and lots of hassle. (It also took my many months to get a warranty issue addressed on a Nitecore HC60 headlamp.)
    The Nitecore LR60 acts as a charger, battery bank, and a lantern but it also leaves too much charge in the battery (compared to the Xtar).
    The Nitecore F21i looks intriguing but I am hessitant to buy more Nitecore products.
    Ideally, I would like an 18650 headlamp that doubles as a battery bank. I bought a handheld like for low cost on Amazon with a discharging feature but it does not work that well and I do not want to depend on it.
    I use a XTAR-PB2S which works well but is a little heavy.

    Any updates or advice would be useful.

  2. Bill

    Why not use 21700 or even larger batteries for longer journeys?

    • Diane

      Those would also work. For me, 18650 are the ideal capacity and they seem to be most popular with other backpackers too. Plus, the smaller size means you can more precisely add more capacity. There’s no reason you couldn’t bring 21700s and 18650s, or some other mix and matching.

  3. Roger

    I carry 18650’s when hiking. The Nitecore F1 is my favorite powerbank using 18650’s as a source, but it is not longer produced, and I’m looking for a backup because these units seem fragile. I am settled on 18650s because they also drive my outstanding zebralight headlamp. The Fenix ARE-X11 is nice, but it charges my phone nearly twice as fast the F1 resulting in a lot of heat production, which may explain why the ARE-X11 only charges my phone a little more than half the percent as the F1.

    Apparently nitecore replaced the F1 with the UL1, BUT according to what I read the UL1 can NOT be used as a battery bank.

    The LC10 looks interesting and I just ordered it, but I expect that it will have a serious issue. When using as a battery bank on the trail, it will likely require my contriving some sort of way to ensure that the LC10 remains connected securely to the battery while in a pocket or backpack. This type of magnetic connector has not shown in my experience to be reliable when jostled around in a pocket.

    When using a battery bank, I prefer individual batteries like 18650 as opposed to a dedicated battery bank. Batteries can fail, so with multiple individual batteries there can be a significant increase in reliability, at least this has proven true with things like ski boot heater batteries.

    I just ordered a the klarus option, however, my old one failed.

    More research required….

    • Diane

      Thanks for the comment. I didn’t think about the failure aspect of power banks. That’s definitely another reason to go with multiple individual batteries… until the charger/device which turns them into a power bank fails!

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