Device Requirements

A device and accessories needed 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.

Devices Used in the Field

Below is a list of devices that team members have used in the field to record specimen data using NAHPU.

Field location	Site type	Days	Specimens	Type	Model	Operating system	Accesories
Java, Indonesia	Tropical mountain	33	196	Tablet	Lenovo Tab P11 Pro	Android	Logitech K380 keyboard, ProCase for Lenovo Tab P11 Pro 11.2", 2 x 25k mAH power bank
Sumatra, Indonesia	Tropical mountain	115	644	Tablet	iPad Mini 6	iPadOS	Logitech K380 keyboard, Zugu Case for iPad Mini 6, 2 x 25k mAH power bank
Sumatra, Indonesia	Tropical mountain	115	>100	Tablet	iPad Mini 6	iPadOS	Otterbox iPad Mini 6 case

Other devices using NAHPU in the field:

iPhone 13 mini used in Mexico field expeditions

Deep Dive

When Budget is a Constraint

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, and a daily project export is far smaller than a full database backup, so a season of daily copies fits comfortably. 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.

Any Budget

A tablet. We recommend using an iPad Mini or a comparable size device. You can also get a bigger iPad. 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 minimize 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 with a USB-C connector that supports fast charging. 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. 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. We recommend at least 65W chargers. Some models supports international travel, featuring switchable plugs for different countries power outlets.

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 on the Inui Amazon Page). 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 from RavPower.