That's fairly simple. Example: my Note 3 battery is rated 7.4 Wh, so a 7W panel I have (Goal Zero Nomad 7, 9"x6.5" folded) should charge it in a bit over an hour under perfect conditions. In reality, I cannot draw 7W out of its USB port, as it's rated for 5 Watt only. Plus, unavoidable loses due to various voltage conversions in the phone, not ideal atmospheric conditions, etc, so I would double or even triple that time. But 3 Hours is not that bad at all, especially if you have a battery buffer, such as the Guide 10 (11Wh) to accumulate the solar power all day (in fact, 3-4 hours, so a second batch of 4 AAs can be charged). By the way, I plan to make an adapter, fitting the Nomad 7's pocket to charge my phone's spare battery on the go.

Hmm, some sort of a glitch with that post happened, a part of it is marked as Censored in the original post and in the quoted text, replaced ebay URLs with shorturls.

For the OP's question, define your INCH event.

To me, an INCH event is where things are really messed up and quite possible that supporting infrastructure is already gone or in bad shape. Meaning, would there still be a need to charge a cell phone? Carrying a few extra batteries for a flashlight is doable depending on supposed INCH event.

Depending on cellphone, carrying extra batteries which are lightweight would be my preference. 4-5 batteries ($50.00 and 8 oz total weight) for my phone would give about 16,000 mAh of battery time and could last months with careful usage. Again, depending on the INCH event, having a 12 volt to USB cable will give a lot of charging options from many sources such as car batteries etc. The 12 volt end of the cable can easily have a cigarette type connector added to it also. I have a similar cable but it has 2x USB connectors and has come in handy and mostly recently during a 32 hour power outage here at home which was caused by a windstorm.

Although the foldable type of solar panel products are decent (there is some real garbage though), they are really not suited for on the go unless you plan to stop for to allow the charger to have enough sun time to charge the batteries. Also what happens if it rains and there are clouds for days on end? Solar charge time may stretch into 10's of hours, if not more.

As for SLA type batteries, they can hold plenty of power but are heavy and not really suited for on the go travel. A better solution especially if you have a phone such the Apple iPhone in which they don't have a replaceable battery, might be the Anker 26800mAh charger Anker is a very reliable brand and makes quality products. One or two of these chargers in a backpack will give plenty of charging capability.

It´s not that simple. If the battery has some sort of lithium based technology it wont be very forgiving when you violate the loading specs. It might catch fire or explode.

Are you talking about the Solar charger for the spare Note 3 battery? Most likely, I will just pick a cheap official USB charger for that battery with proper connector and 3D print a different casing for the circuit, so it fits better in the Nomad's pocket. Most of the chargers I see are quite bulky looking and/or seems insecure for charging on the go (slot type) when Nomad is hanging from the backpack unfolded.

Some lithium technologies are more tolerant than others. Paraphrased from http://www.candlepowerforums.com/vb/showthread.php?317698-Lithium-IMR-vs-ICR-vs-IFR:

ICR == LiCoO2 == What most people think of when they say "Lithium Ion batteries" == can be prone to "venting with flame" when violating the loading specs. Be sure to use high-quality, protected cells.

IMR == LiMn == Good for high-drain use but has less capacity == Can overload but significantly less likely to go into thermal runaway and also less likely to hurt you or your equipment if it does. Always use high-quality cells, nobody makes them with PCB protection as far as I can tell (because you don't need it).

IFR == LiFePO4 == Longer cycle life, better power density and safer than ICR, needs a LiFePO4-aware charger in order to charge safely. Be sure to use high-quality, protected cells.


Most of my rechargeables are NiMH or ICR, but I do have some IMR cells for specific applications. I also only buy high-quality cells and use a high-quality charger.

Cell Choice is important and pretty dependent on the application.

For example if you need to see in the dark then a torch might be required. If you want to see quite a distance in the dark then a high Lumen torch is required with a large high drain cell such as a 26650 Lithium Ion Cell. Flashlights with powers exceeding 10W may allow you to see a few hundred yards and last around 2 hours.

You can take a different approach and use an Image intensifier tube.

An Image intensifier tube may use around 0.2W and a single 26650 Lithium cell would last 100 Hours.

The power requirement is 50 times less. The charging requirement is 50 times less. The size and weight of the flashlight and Intensifier tube may well be similar.

Rechargeable Alkaline Cells could then even be competitive against rechargeable lithium ion cells with their better low self discharge rates of 4% per year compared to 40-60% for the Lithium ion.

It is also about the charge time calculation. The charge time calculation needs to take in account that your permissible charging current is limited. With an official charger for the battery you should be on the save side.

There are a ton of great "Battery Banks" on the market that give you the ability to carry several days of charge.

Beyond that, Solar (150w) in a fold up pack that can be mounted to a backpack that charges a "Battery Bank" while on the go would probably be my next choice.

I have also seen some "Fuel Cell" options out there, that look good, still have the limitation that once you run out of "cells", your stuck. The energy density is better than batteries, but your still capacity limited.

A lot of brands have already been mentioned here, but I have fondness for Anker. They are price competitive, and have a wide array of Banks/Panels and Chargers for every need.

I personally own several of their products, and have never been disappointed.

Rod

INCH event = Current conficts in North Africa, Middle East, and the Ukraine that is resulting in mass exodus of refugees to Europe. Refugees, once they're out of the conflict zone, will have access to mobile networks with the purchase of a local SIM card.

From what I have seen in the news pictures, the refugees are carrying any combination of casual backpacks, medium size conventional suitcases, and/or large cloth-bound bundles (I'm assuming regional carry technique).



Entry level, brand name, "International" smart phones can be had relatively cheap. I paid $60 for a previous generation LG (non-international). It lacks the bells and whistles of the more expensive phones, but I can call, text, navigate, and access the web on it. The only things I don't have, but wish I did is OTG capabilities

Image intensifier tube = night vision goggles? Expensive option for anything newer then a Gen1 and about the weight of a 3D or 4D maglite. Unless you want to use it to bribe someone, there are better INCH options.