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Device Requirements

The necessary equipment for using NAHPU will depend on your specific field site and budget constraints. We provide a list of common devices and accessories that are typically required, tailored to various field budgets. These recommendations stem from our hands-on experience in remote tropical field sites with limited access to electricity. Please note that you may need to customize this list to better fit your unique field conditions

Table of Contents

Low-budget Option​

  • A smartphone. You can start by using your own smartphone. The NAHPU UI is designed to adapt to small screens.

  • Data Backup Solution. You can use a 16 Gb flash for data backup. It should be sufficient for multiple backups. Our four-month fieldwork experience demonstrated that a database containing 230 high-resolution images used approximately 820 Mb of storage space.

  • A power bank. Depending on the length of the fieldwork and your access to electricity, you may need a power bank to re-charge the device. Our experience using iPad Mini 6, a single charge can last at least for five days with limited camera usage and screen brightness, and was strictly used for data collection.

  • A usb-c or lightning to usb adapter. You can use this adapter to connect your flash drive to your smartphone. Some flash drives have a usb-c connector. If you are using a recent Android or iPhone, you may not need this adapter.

Medium-budget to High-budget Option​

  • A tablet. We recommend using an iPad Mini. You can also get a bigger iPad. Keep in mind that the iPad Mini tends to have smaller battery capacity than a bigger iPad, while still having the same battery life. It allows more recharge for the same power bank capacity.

  • An external wireless keyboard. It helps you to type faster and avoid touching the screen with dirty hands.

  • A usb-c flash drive. Get a high quality flash drives with USB-C connector. Some of these flash drives are waterproof.

  • A power bank. We recommend using a 20,000 to 25,000 mAH power bank. It is usually airline approved. The weight to capacity ratio is also good. It is also good to have a power bank with a USB-C connector. It often allows to fast charging the devices. It also allows you to charge the power bank faster. For example, at the Esseltyn's lab, in fieldwork in remote mountains in Indonesia, we sometimes have guides that can bring the power bank to the nearest village to charge it. A 25,000 mAH power bank with USB-C connector can be charged to full in 4 hours, while a 20,000 mAH power bank with micro-USB connector can take 8 hours or more to charge to full.

  • Multi-output wall charger. It allows you to charge multiple devices at once. We recommend at least 65W chargers. Some brands has travel compatible, featuring switchable plugs.

Power Bank Capacity and Number of Charges​

Power Bank Capacity (mAh)​

The capacity of a power bank is measured in milliampere-hours (mAh). It represents the amount of charge the power bank can store. Essentially, the higher the mAh rating, the more energy the power bank can hold.

Calculating Number of Charges​

To estimate the number of charges you can obtain from a power bank:

Identify Your Device’s Battery Capacity​

First, determine your device’s battery capacity. This information is usually specified in milliampere-hours (mAh). For example, the iPad Mini 6 has a battery capacity of 5,124 mAh.

Factor in Efficiency​

Power banks are not 100% efficient; some energy is lost during the charging process. INUI power banks, for example, recommend industry standard efficiency of 60% (check out FAQ here). Other power banks may have different efficiency ratings.

The number of charges can be calculated using the following formula:

Number of charges = (Power Bank Capacity (mAh) × Efficiency)​ ÷ Device Battery Capacity (mAh)

For example, to calculate the number of charges for a 25,000 mAh power bank with 60% efficiency charging an iPad Mini 6 with a 5,124 mAh battery:

Number of charges = (25,000 mAh × 0.6) ÷ 5,124 mAh = 2.9 charges

Learn more about power bank efficiency and how to calculate it here.

Strategies to manage devices battery life​

  • Screen Brightness: Lower the screen brightness or enable the auto-brightness feature. A dimmer screen consumes less power.

  • Airplane Mode and Low Power Mode:

    • Airplane Mode: Enable it to disable all wireless connections (Wi-Fi, cellular data, Bluetooth) when not in use.
    • Low Power Mode: Activate this mode on your device to optimize battery usage.

  • Power Off After Use:

    • Android Devices: Turning off the device completely when not in use can be beneficial for battery conservation.
    • iPhone and iPad: Apple devices are generally good at managing battery usage, you may not need to power them off.

  • Disable Unnecessary Features:

    • Bluetooth: Turn it off when not actively using external devices (e.g., keyboards).
    • Location Services: Limit other apps’ access to your location, as constant tracking drains the battery. NAHPU only uses location services when you generate a coordinate for a site using the device’s GPS.
    • Cellular Data: If your devices supports cellular data access, consider disabling it to save power.