| While there are many ways to go about the task of | | | | chargers come equipped with 12VDC car adaptors in |
| charging batteries & electronic devices via solar | | | | addition to AC adaptors. There are also AA chargers |
| power, we will focus on several solutions that have | | | | that can operate from USB or 12VDC car sockets. So, |
| been tested & proven, and which cover the most | | | | since we can get 12VDC output direct from the solar |
| common needs. We also recommend using PowerFilm | | | | panel, and USB via a car adaptor, at this point it |
| Rollable solar panels that are the most appropriate on | | | | appears that we could choose to charge all our |
| the market for portable marine applications and for | | | | devices direct from solar and not include the power |
| strapping to the decks of kayaks & canoes. | | | | storage battery pack. But, should we go solar direct? |
| Step 1: Estimate your power needs | | | | We almost always advise using solar-direct only when |
| The first step in creating a solar power system for | | | | the trip is short, the weather forecast is positive |
| kayak expeditions or canoe trips is to estimate your | | | | (& reliable), and the solar panel is really only |
| total power needs, and choose a solar panel to match. | | | | needed to top-up your batteries when needed. Having |
| Watt-Hours is a measure of a battery's capacity. For | | | | the power storage pack provides an important source |
| example, most digital cameras require 5-10 | | | | of back-up power for times when the sun is not |
| Watt-Hours, mp3 players require 5, laptops require up | | | | cooperating. It also allows your battery chargers to |
| to 65. | | | | operate at their best rates instead of limping along at |
| Next, decide how often you will need to charge your | | | | whatever the solar panel is able to get from the sun. |
| various devices. For example, if you want to charge | | | | You will also be able to capture more of the sun's |
| your digital SLR camera while canoeing or kayaking, | | | | energy over the course of the day. |
| and you know that under typical use, you get 3 days | | | | For our example, we would recommend the Voltaic |
| from the camera battery before it needs charging, | | | | Pack. It's capacity is slightly larger than our one-day |
| then your needs are 15 WHrs over 3 days = 5 WHrs | | | | needs, and it is very small & light. It also includes all |
| day | | | | the USB & 12V connector capability we would |
| To complete this example, we'll add the need to | | | | need. Although the Voltaic Pack will not support a |
| charge two AA batteries each day for a GPS unit, | | | | Targus camera charger for 7.4V battery packs, this |
| and an iPod every other day. Total daily power needs: | | | | function can be obtained by connecting the camera |
| 12 WHrs | | | | charger direct to the panel. If the power storage pack |
| For portable applications, we like to be conservative | | | | is needed to drive the Targus charger for 7.4v battery |
| when estimating the power production from solar | | | | packs, then the best option would be to choose the |
| panels. It is nearly impossible to get ideal exposure for | | | | Voltaic "Generator" battery unit. |
| a solar panel when it is simply strapped to the deck of | | | | What About AA Batteries? |
| your kayak, draped over your tent, or spread from rail | | | | For most canoe & kayak expeditions, one of the |
| to rail on your canoe. So, solar production may be only | | | | most common needs we hear about is AA battery |
| about half of what a properly engineered | | | | charging for things like GPS receivers & radios. |
| roof-mounted system might be. Based on this | | | | We advise customers to consider two scenarios... 1. |
| assumption, we can calculate that a 5Watt panel | | | | Direct solar charging of AA batteries 2. Using an |
| would meet our needs, minimize costs, and minimize | | | | intermediate power storage battery |
| size & weight to carry. Remember that this is our | | | | In the first option... The solar panel is connected directly |
| power budget, and therefore we must live within this | | | | to a DC-input AA battery charger. We recommend |
| amount. The other advantage of minimizing the solar | | | | the following equipment pair... PowerFilm R15-300 or |
| as much as possible is being able to fit it to the deck | | | | PowerFilm R-7 Targus Mini 12V DC AA Charger |
| of your canoe or kayak. PowerFilm Solar produces a | | | | The charger will operate any time the daylight gets |
| range of flexible solar panels designed for use on | | | | bright enough, and will charge at the maximum rate of |
| boats. They are designed to take the splashes | | | | the solar panel in the light conditions. For example, this 5 |
| associated with marine applications, and come | | | | Watt solar panel will charge 2 batteries per day from |
| equipped with the best connectors we have seen on | | | | late spring through early fall. Most people will create a |
| a portable solar panel. The R-7 7Watt rollable panel is | | | | "battery rotation" whereby pairs of batteries are in the |
| the smallest in this marine-grade line, so that is the | | | | charger, charged & ready, in the device, & |
| panel we would choose for our example system. | | | | waiting to be charged. Every day, the batteries are |
| Step 2: Choose a power storage battery & | | | | changed & moved up the rotation. This way, |
| conectors | | | | charged batteries are never mixed with partially |
| Next is to choose a battery pack to store your solar | | | | charged batteries in your device. If you want faster |
| power. It should be small & light so as to not load | | | | performance, and more batteries per day, upgrade to |
| your canoe or kayak any more than necessary. It | | | | the 10W or 14W PowerFilm panel. These will charge |
| needs to provide the connectors you need to charge | | | | as many as 8 AA batteries in a summer day. |
| all your devices. It should also store enough power to | | | | The second option... This power system allows you to |
| get you through times when the sun isn't as bright as | | | | store solar power during the day, and draw power |
| we would hope. We like to make an estimate that is | | | | when you need it, even at night. Besides having |
| at least equal to your daily needs. In our example, this | | | | access to power anytime, an important advantage of |
| would mean a storage capacity of at least 12 | | | | using an intermediate battey is being able to operate |
| Watt-Hours. | | | | the battery chargers at their peak rate, and not just at |
| Want to work direct from the solar panel, and not | | | | the present rate of the solar panel. We recommend |
| carry a power storage battery pack? We'll have to | | | | the following equipment... PowerFilm R15-300 or |
| see if the devices you want to charge will be able to | | | | PowerFilm R-7 ZAP! R07-PL2 Battery Pack Targus |
| do this. Read on... | | | | USB AA Battery Charger |
| In our example from above, we will need the following | | | | Or, for more power, combine the 10W or 14W panels |
| connectors... USB: for our smart phone AC outlet: for | | | | with the Voltaic Battery Pack and the Targus USB |
| our camera & AA battery charger. Wait! AC | | | | AA Battery Charger. |
| power is not an option in these small power systems. | | | | NOTE: It is imperative that all batteries have ample |
| AC power inverters will not operate direct from solar | | | | airspace and be vented somewhat while they are |
| panels, and the small lithium-based power storage | | | | being charged. If using a dry bag, be sure to leave an |
| battery packs are not able to power even a small | | | | airspace, and preferably do not completely seal the |
| inverter. What to do? | | | | bag. That's It... You are Ready to Start Paddling with |
| Fortunately, many after-market lithium camera battery | | | | Power! |