Problem: Our families need to charge their cell phones and tablets but have no AC power available.

Solution: Use two  Solartec Daisy-Chain XT60 panels SOLARTEC15-DAISY connected to the Half-Pint-XT Solar Power System Half-Pint-XT and add an Anker 5-port charger from Amazon.

You will find that a pair of Solartec solar panels plus the handy Half-Pint power bank make up a power system just right for charging multiple cell phones and tablets, a system that lasts for thousands of recharge cycles. If you haven’t permanently installed the Solartec panels, you can even transport the system with relative ease; it weighs about 12 pounds. If you intend to mount the panels be sure to get the Mounting Kit for Solartec 15-W Solar Panel SOLARTEC15-MOUNT and consider whether you may need longer cables.

What can I charge?

The Half-Pint battery stores 72 watthours of energy; that’s enough to charge eight to ten smartphones, or three 7-inch tablets, or two 10-inch tablets. The panels will actually put out nearly twice that much in a day, so you can charge eight phones and your Half-Pint battery at the same time. If you have several sunny days in a row, you can actually charge more than eight phones per day, if you charge while the sun is shining. If you’re not going to charge more than four phones per day, you could run with only one of the 15-W Solartec panels.

Using the system

For charging the Half-Pint power bank, you plug the solar panels directly into the power bank using the extension cable(s) attached to the panels. You don’t need any adapters for this connection. The power bank will take about three hours in full sun to fully charge with the two Solartec solar panels; you should be able to get a full charge on even partly cloudy days.

The Half-Pint power bank is more than just a battery in a box. It contains electronic elements to protect the battery from being over charged by the solar panels and to prevent you from damaging the battery by draining it completely. You can check the battery’s level of charge by pressing the button on the top of the case to see the battery’s voltage on the built-in meter.

The power bank is based on a LiFePO4 (lithium iron phosphate) battery so it will outlast “normal” lithium and lead acid batteries. This will save you money over the long run. When fully charged the battery’s 72-Wh capacity stores enough energy to charge, without any sunshine,  six to eight smartphones, like the iPhone 6, or a couple of iPads (For the sake of simplicity count each tablet as three smartphones.) But the battery is only a temporary holding tank for the power produced by your panels. The main limiting factor in what you can charge each day is the size of the solar panel(s) (in watts) and the amount of sun available.

A locking cigarette lighter jack on the side of the Half-Pint serves as the power bank’s only output, 12 V dc (nominal). Plug the Anker 5-port charger (or similar) into the cigarette lighter jack and use appropriate USB cables to connect each phone or tablet to one of the USB charging ports. You can use any “automotive” power adapter designed for your equipment; if you want to plug in more than one at a time, just use a 3-way cigarette lighter splitter like this:

Cigarette Lighter Triple Socket Adapter

just don’t exceed 6 amperes total (72 watts.)

It is important to understand that this solution does not provide any ac power, only dc. That means, for example, that you can’t use your phone’s ac adapter to charge it from the Half-Pint power bank. You can, however, charge using your phone’s car charger by plugging it into the Half-Pint cigarette lighter jack.