[Gocamino] Tech report

[Robert Spenger]

Report on solar chargers, power cells, and tablets.
 
Warning! Totally tech talk. Pilgrimage purists please pass by present post. Egad. I seem to have assumed an awful alliteration addiction.
 
This is as report on a test of a couple of Goal Zero Solar Charger kits and the use of the GZ power pack to charge an iPad mini.
 
The Guide 10 Plus Adventure Kit uses the Nomad 7 solar charging panel. As the name suggests, this is a 7watt unit. I got it from REI for $120 and that included a flashlight that has little solar panels built into it. The flashlight was an unexpected extra that has nothing to so with the use of the main kit. I was satisfied with the operation of the kit, but decided that it is too heavy for daily backpacking use. Weights:
 
Solar panel                                                                	 441g
4 Goal Zero NiMH AA power cells, 29g each          116g
Cell holder/charging unit                                         59g
Cord with automobile type socket                                32g (no use to me on a walk)
Cord with USB outlet                                                        20g
AAA cell adapter                                                   15g (no use to me on a walk)
Cord for the cell charging unit                                              9g
Total                                                                            692g
 
Without the auto socket and the AAA adapter             645g
 
The Guide 10 Plus Mobile Kit uses the Nomad 3.5 solar charging panel and, naturally, is a 3.5watt unit. I don’t see it listed on the REI site, but according to my records, I bought it from there for $80. No bonus flashlight with it. Also it has no auto socket and no AAA adapter. The weight of this one is acceptable to me for walks and I can use the 7 watt  kit for auto trips. Weights:
 
Solar panel                                                                  222g
4 cells                                                                          116g
Cell holder                                                                     59g
USB cord                                                                      20g
Charger cord                                                                   9g
Total                                                                            426g
 
As for the weight of the iPad mini itself, plus accessories:
iPad with protective  cover  added                            319g
Padded sleeve case                                                     139g
Smart cover                                                                   66g
Charging plug for US 110V outlet                             23g (would also need a travel unit)
Cord                                                                              18g
Total                                                                            565g                                                   
 
Summary of tests:
 
The GZ cells are apparently much like the Sanyo Eneloops in that they have a far greater shelf life than the usual NiMH cells. Both types seem to behave about the same when they are charged with the Nomad panels, and they gave similar results when they were used in the holder to charge up the iPad mini. A set of 4 fully charged cells, which would show between 1.3 and 1.4 volts, would boost the iPad mini cell by 25-30%. For me that would be enough to carry me over until such time as I could get access to a regular power outlet and get a full charge.  The charge transfer time was about 1 hour. It takes about twice as long to get the same boost with a 110 volt outlet.  The AA cells ended up at just under 1.2 volts. Recharging the AA cells with the 3.5 watt solar charger took 4 or 5 hours in good sunlight, but it was not always at the best angle. I just left it out, checking once in a while to make sure it was not in the shade. I suppose that it would be more efficient to charge the iPad mini directly with the solar charger, but I would find it more convenient to do it by way of the AA cells. I would also consider carrying the second charger/holder unit and an extra set of 4 cells. With that setup, I could have one set being charged while the other set is being used to charge the iPad or any other device that has its power unit locked inside.
 
There is a lot of pack weight here, but iPad mini can store a lot of stuff that I would otherwise have to carry. That still leaves the question of whether or not I would want to have to rely on an electronic device that can go out of order at any time. Maps, guidebooks, dictionaries, and the like can get soggy in bad weather, but would still be usable. A water soaked tablet, cell phone, or whatever, might not fare so well.
 
Bob S.