We’ve all seen the neat solar backpacks that are starting to pop up on college campuses and in office buildings everywhere. They offer their owners the option of recharging items like phones and GPS devices without being tied to an electrical outlet. When someone walks through the crowd wearing one of these, you can practically see the light bulbs above the heads of technologically savvy people with a big caption that reads “DIY solar backpack!!”
With visions of fast charging, super power capacity, and customized features running through their heads, they set out to build the perfect DIY solar backpack. Soon a little research confirms the hard truth that it is difficult to piece together a better solution than those being mass produced. Setting aside the fact that poorly wired components can burst into flame and assuming you have the skills to do a safe job of it, let’s look specifically at what makes it a tough task to build a DIY solar backpack.
The best solar backpacks on the market have panels that require 7 hours of direct sunlight to go from completely drained to fully charged. This is the first area that would-be DIYers want to change. It is easy to find solar panels that massively outperform those used in most backpack applications. The problem is that they’re both too expensive and too large to be attached to a DIY solar backpack. The panels need to be small enough to allow someone to use the backpack without getting in the way.
The second feature people generally throw into their dream DIY solar backpack is a battery with massive storage capacity. The best solar backpacks on the market today generally have the storage capacity to recharge an Iphone four or five times. To get far more storage capacity would either require massively heavy batteries or extremely expensive ones. The inexpensive, heavy batteries would also require far more space in the pack than the costly but compact NiMh batteries.
At a glance, most people don’t even consider this component when thinking about a DIY solar backpack. The solar panels will attempt to charge the battery as long as light is available. The charge controller is necessary to change the batteries’ mode from ‘charge’ to ‘store’. Also, the devices to be charged could be damaged without a good charge controller to stop charging at the proper time. Since tiny, inexpensive charge controllers are not a common component in portable DIY electronics projects, an expensive and bulky option designed for non-portable use may be the only choice.
The best solar backpacks look professionally made. Look at your average car stereo enthusiast’s vehicle and it’s clear that most people do not have what it takes to perform a clean, professional electrical installation free of hanging wires, visible electrical tape, and sloppy access holes. Creating a custom DIY solar backpack will require cutting holes for wires, attaching solar panels, and threading wires through the backpack straps. Doing this with professional looking results requires the ability to do so without fraying cloth or holding the whole contaption together with electrical tape.
If you have the electronics skills to connect the components safely, the design skills to make the package neat and professional, and don’t mind the added cost or time required to do so, you may be able to produce as perfect a DIY solar backpack as is possible today. For the rest, chances are, the best solar backpack option is to choose a professionally manufactured one.