During this second consecutive summer of heavy canoe camping traffic, conversations at the put-in reveal a notable change. Part of the calculation on every portage is no longer distance; it is battery percentage.
Paddlers check the phone's charge, the power bank's remaining capacity and the number of days left, and consider whether the map really needs to come out the next day.
On our first trip in Algonquin, some thirty years ago, the only battery-powered item was a flashlight, with a couple of spares packed and forgotten. Today, nearly everyone on the water carries a phone for maps and photos, many carry a GPS or a satellite messenger, and some bring a camera and a headlamp that charge by USB. Paddlers no longer simply carry batteries; they need a power plan.
What is the most effective way to save battery in the backcountry?
Airplane mode. This is the first measure to adopt, before purchasing any equipment. A phone without a signal does not remain idle: it continuously searches for a tower, and that search consumes power. In the backcountry, a phone left in normal mode can drain completely in a single day without performing any useful function.
Airplane mode stops this process. On most phones, GPS continues to work in airplane mode, so offline maps still show your position. Calls and data are disabled, but they were unavailable in any case.
Several other practices also help:
- Lower the screen brightness and shorten the auto-lock delay.
- Close apps that track your location in the background.
- Consult the map at decision points, such as the start of a portage or a fork in the lake, rather than leaving it open.
- Take photos in short sessions and put the phone away, rather than keeping it out all day.
These measures are simple, and they extend autonomy by more days than a larger battery would.
What size of power bank does a canoe trip require?
For most trips of up to a week, a good power bank is sufficient. A 10,000 mAh bank typically provides a modern phone with approximately one and a half to two full charges, depending on the phone and on transfer losses. The capacity printed on the bank is not what reaches the phone; part of it is always lost during the transfer.
For longer trips, paddlers can carry two banks or one larger unit. Beyond a certain point, however, the weight becomes a burden on every portage, and this is where solar power becomes worthwhile.
Keep the power bank and cables in a dry bag. We do not recommend relying on a power bank that has been submerged.
How does cold weather affect lithium batteries?
Significantly. In July, this factor can largely be disregarded; for spring and fall paddlers, it cannot.
Lithium-ion batteries lose usable capacity in the cold. A phone showing 40 percent in the evening may drop to 15 percent by morning after a frosty night in the tent, or shut down entirely. Most of that capacity returns once the battery warms up, which is of little help at 6 a.m. when the map is needed.
Charging presents a second issue. Manufacturers generally advise against charging lithium-ion batteries below freezing, as it can damage them. We therefore recommend waiting until both the phone and the power bank have warmed up before charging on a cold morning.
How can batteries be kept warm?
Keep the phone and power bank in an inside pocket during the day. At night, place them in the sleeping bag or in a stuff sack at its foot. The practice may seem unusual at first, but it is effective.
Is a small solar panel worth bringing?
For the essentials, yes. Portable solar panels have improved considerably and become more affordable over the past few years. A foldable panel of approximately 10 to 20 watts can top up a phone or a satellite messenger over a sunny day. It cannot power a laptop and does not charge quickly, but it is sufficient for essential devices.
The amount of energy actually produced depends on the sun, not on the rating printed on the box. Natural Resources Canada provides a clear explanation on its page on solar photovoltaic energy. Panels perform best when facing the sun directly, and output drops considerably under cloud cover or partial shade.
On a canoe trip, this translates into several practical guidelines.
Strapping a panel to the top of a pack while walking a portage under the trees produces little energy. Laying it flat on the packs in the canoe on an open lake is more effective. Propping it up to face the sun at a campsite over lunch is the most effective. Charging a power bank from the panel, then charging the phone from the power bank at night, usually gives better results than connecting the phone directly, because panel output fluctuates each time a cloud passes.
A panel is a backup, not a complete plan. After three days of rain, it provides no useful power.
How much power is actually needed?
Our current approach is as follows.
Identify the essential devices. For most paddlers, these are the phone for maps and a satellite messenger for emergencies. Everything else, such as photos, music or an e-reader, is optional. Plan power for the essentials with a safety margin, and allow the optional devices to use whatever remains.
A satellite messenger with its own long-lasting battery should be protected above all else, since it is the device needed on the most difficult day of the trip. We would let the phone run out of power before allowing the messenger to do so.
We also recommend bringing a small headlamp that uses standard batteries, or at least a charged headlamp reserved for emergencies. Being left in the dark because every light source depends on the same power bank is an entirely avoidable situation.
There is a certain paradox in heading into the backcountry to get away from screens, then spending part of the evening managing their batteries. We are no exception, and our recommendation is to keep the list of devices short.
More trip-planning articles are available on the blog.