Application Notes:
Solar Charging For Kayak & Canoe Trips The right way to stay charged while out on the water
This note is provided as a guide to kayakers who want to be able to charge batteries, digital cameras, video cameras, media storage devices, MP3 players, & other electronics while out on the water. We're using this page to highlight the best in ruggedized solar panels for marine use, along with the lightest power storage & battery charger options available.
While there are many ways to go about the task of charging batteries & electronic devices via solar power, we will focus on several solutions that have been tested & proven, and which cover the most common needs. We also recommend using PowerFilm Rollable solar panels that are the most appropriate on the market for portable marine applications and for strapping to the decks of kayaks & canoes.
Really compact solar & dynamo chargers...
Personal Power Gear Smaller hybrid solar equipment for GPS, phones, iPods, mp3's, etc.
Solar & dynamo kits
Complete power solutions with AC & DC output for larger needs.
THE SHORT ANSWER...
Here is the outline of the most common set of equipment we outfit kayakers & canoeists with...
The PowerFilm panel is waterproof, and can be strapped to the deck of a kayak using its corner grommets. It has a gasketed connector & will take a roll, but in all reality should not be submerged for long. A 12V cigarette socket outlet is provided for the panel... to directly connect 12V devices or plug in the storage battery...
The Novuscell 24 is the smallest, lightest 12V battery pack we've come across. Lithium-based, so it is the size of a deck of cards, but holds 1.5x a dSLR battery, and matches well to the output of the PowerFilm R7 panel. A 12V socket is provided, along with an Apple-friendly USB port, so you have all your iPods, smart phones, and GPS units covered. Keep it protected under the deck in a mini dry bag.
The Ansmann Vario is the very best universal battery charger available. It covers all 3.6V & 3.7V P&S camera batteries, all 7.2V & 7.4V camcorder & dSLR batteries (with the exception of the Canon LP-E6). Very easy to use, with no special adaptor plates to lose. You can charge during the day by connecting this to the battery, but most people wait until camp to do all their charging for the day.
and now... THE LONG ANSWER...
Step 1: Estimate your power needs
The first step in creating a solar power system for kayak expeditions or canoe trips is to estimate your total power needs, and choose a solar panel to match. Following is a table of the Watt-Hours needed to charge various common electronic devices. Watt-Hours is a measure of a battery's capacity.
Device
WHrs
Device
WHrs
iPods
6
Camera
6
Cell phones
4
SLR Camera
15
2x AA Batteries
8
Laptop
65
Next, decide how often you will need to charge your various devices. For example, if you want to charge your digital SLR camera while canoeing or kayaking, and you know that under typical use, you get 3 days from the battery before it needs charging, then your needs are 15 WHrs over 3 days = 5 WHrs/day
To complete this example, we'll add the need to charge two AA batteries each day for a GPS unit, and an iPod every other day. Total daily power needs: 12 WHrs
For portable applications, we like to be conservative when estimating the power production from solar panels. It is nearly impossible to get ideal exposure for a solar panel when it is simply strapped to the deck of your kayak, draped over your tent, or spread from rail to rail on your canoe. So, solar production may be only about half of what a properly engineered roof-mounted system might be.
Following are reasonable estimates for the various PowerFilm rollable panels (these are ideal for boating applications). These performance numbers are for the summer months May-August...
Panel
WHrs/Day
Spotlight...
PowerFilm
The flexible solar panels for portable marine applications. Choose from 7Watt to 28Watt sizes. Waterproof with marine-grade connectors Check them out...
Based on this table, we can see that the smallest panel (R15-300) would meet our needs, minimize costs, and minimize size & weight to carry. Remember that this is our power budget, and therefore we must live within this amount.
The other advantage of minimizing the solar as much as possible is being able to fit it to the deck of your canoe or kayak.
Step 2: Choose a power storage battery & conectors
Next is to choose a battery pack to store your solar power. It should be small & light so as to not load your canoe or kayak any more than necessary. It needs to provide the connectors you need to charge all your devices. It should also store enough power to get you through times when the sun isn't as bright as we hope. We like to estimate at least equal to your daily needs. In our example, this would mean a storage capacity of at least 12 Watt-Hours.
Want to work direct from the solar panel, and not carry a power storage battery pack?
We'll have to see if the devices you want to charge will be able to do this. Read on...
In our example from above, we will need the following connectors...
USB: for our smart phone
AC outlet: for our camera & AA battery charger
Wait! AC power is not an option in these small power systems. AC power inverters will not operate direct from solar panels, and the small lithium-based power storage battery packs are not able to power even a small inverter. What to do?
Fortunately, we carry a wide range of lithium camera battery chargers and these come equipped with 12VDC car adaptors in addition to AC adaptors. We also carry a range of AA chargers that can operate from USB or 12V sources.
So, since we can get 12VDC output direct from the solar panel, and USB via a car adaptor, at this point it appears that we could choose to charge all our devices direct from solar and not include the power storage battery pack. But, should we go solar direct?
We almost always advise using solar-direct only when the trip is short, the weather forecast is positive (& reliable), and the solar panel is really only needed to top-up your batteries when needed.
Having the power storage pack provides an important source of back-up power for times when the sun is not cooperating. It also allows your battery chargers to operate at their best rates instead of limping along at whatever the solar panel is able to get from the sun. You will also be able to capture more of the sun's energy over the course of the day.
To help you select the most appropriate power storage device for your kayaking & canoeing needs, we've put together the best matches for the PowerFilm rollables in marine applications.
Please check out POWER PACKAGES page for complete descriptions.
For our example, we would recommend the Novuscell 24 battery pack. It's capacity is slightly larger than our one-day needs, and it is very small & light. It also includes all the USB & 12V connector capability we would need.
Need a laptop? Or need to charge more or bigger electronics?...
Choose one of the larger PowerFilm rollable solar panels...
* Estimate only. Actual performance depands on weather, location, time of year, and laptop performance.
As indicated in the table above, these larger panels are best used with the Brunton Solo battery packs. The PowerFilm panels can be daisy-chained together very easily using their optional RA-6 Daisy-Chain accessory, so you can combine panels to get more power. Remember not to exceed the maximum for the battery pack (two PowerFilm 28 panels is the maximum input to the Bruntons).
While there are many ways to go about the task of charging batteries & electronic devices via solar power, we will focus on several solutions that have been tested & proven, and which cover the most common needs. We also recommend using PowerFilm Rollable solar panels that are the most appropriate on the market for portable marine applications and for strapping to the decks of kayaks & canoes.
