Power Banks for Portable Power

When living off grid, there is still often a need – or at least a desire – to use electricity. One notable purpose is for charging a cell phone, which may be the only communication available for some who live off-grid.

While many devices are becoming more efficient in power usage, it is still likely that most need to be charged daily, or at least every other day. This can be challenging when living without an electrical connection. Having one or two power banks can make it easier, as the device and the power bricks can be charged from a generator or solar panel, while the banks will allow the device to be recharged without needing to run the generator.

What is a Power Bank?

A power bank is a portable power source, which contains one or more rechargeable batteries and has input and output ports. They are generally small enough to fit into a pocket, and the weight usually varies by the capacity – or should. If a power bank claims a high capacity but a very low weight, one of the numbers is likely incorrect.

This is because a power bank is powered by battery cells, similar to the AA batteries that are inserted into flashlights or other electronic devices. These rechargeable batteries are connected in parallel to increase the overall capacity. If the capacity is high, it requires more batteries to achieve that number. If there are fewer batteries (for less weight), then the capacity is necessarily lower.

Because of the way the batteries are connected, and because of the type of batteries they are (lithium ion or lithium polymer), these batteries could overheat. Manufacturers make it so the charge circuit manages the voltage, but cells could be damaged or faulty and result in an explosion. This means that choosing power banks that are good quality is very important.

What to Look For

Power banks vary in capacity, size, and quality. It can be difficult to determine quality, but this is inextricably linked to the capacity. If the power bank claims a high capacity but weighs very little, it is likely to be of low quality. If it claims a high capacity and has a very low cost, remember that one generally gets what one pays for – therefore a low-cost power bank will probably be low quality.

A brand name power bank is often a better choice, as a brand usually has some incentive to maintain better quality control and are usually careful to make products that will not cause people to be negative about the company.

When preparing to purchase a power bank, look at reviews. Those written by people who have actually used the power banks will give some idea of what to expect, both from capacity and quality.

Lithium polymer batteries are generally safer than Lithium ion. For further safety, choose a power bank that has a capacity that is close to that of the device being charged. Recharging the power bank between charges is not usually much trouble, and, despite the label, a 10,000 mAh battery is unlikely to recharge a 2500 mAh phone four times. This is due to differences in wattage, as well as energy conversion.

Looks for consumer safety certification; this means that the batteries have been examined and approved.

Some power banks are made with solar panels built in, allowing the bank to be charged without a generator or electrical connection. These do often take longer to charge but can also be charged with a cable if needed. However, when living completely away from the electrical grid, these may be a wise choice.

Probably the most important thing is to be sure that the power bank has ports that work with the devices that will be charged. In most cases, a standard USB port will serve this purpose, as cables that are used to charge devices are often USB to micro-USB or USB-C. However, if there is a specialized device that will need to be charged, make sure that the power bank will work with it to prevent disappointment.

Charging Dangers and Considerations

USB ports usually charge at 5 volts and .5 amps. When the voltage does not change but the amperage increases, the potential flow of energy also increases. This results in a faster charge for the device and equally a faster discharge for the power bank, as long as the device supports it. Because devices pull current rather than pushing it, there is no problem in plugging in a device that uses less amperage than the port can support.

However, when the power bank discharges faster, it increases the heat in the battery. Hotter batteries are less efficient and may result in less charge overall.

For best results, when charging, turn the phone or other device off. Charging on a faster port is usually best, but especially if it becomes necessary to charge the device while using it; otherwise, it is likely to continue to drain despite the added power.

Choosing a power bank that supports pass-through charging is good when it is often necessary to charge a device at the same time one is charging the power bank; both items can charge with one power source with this type of battery.

Resources

Product
Visual
Where to Buy
4000 mAh Power Bank
PowerCore 10000 mAh Compact Power Bank
Solar Power Bank

1. 4000 mAh Power Bank

Supporting a 2.1A fast charge, this charger has LED indicator lights to aid in knowing when to recharge the charger’s lithium-ion batteries. It is compatible with virtually any device.

2. PowerCore 10000 mAh Compact Power Bank

Lithium polymer batteries power this charger which is compatible with most devices. It will recharge an iPhone 8 more than three times and a Galaxy S8 more than twice, at high speeds with the 2.4-amp capability. It has 11 safety features to charge safely and efficiently.

3. Solar Power Bank

Recharge your mobile phones outdoor using solar power with this high-capacity solar power bank.  Its OKOO 22W folding solar panel makes the charging of your phone really fast and it also has features that prevent overheating, overcharging, and even overloading the charger. Each USB charging port has up to 2.4A max, 5V DC  capacity. It works in almost all brands of mobile phones.