NAHPU runs natively on mobile and desktop operating systems, and each platform carries its own limitations and trade-offs. We recommend a mobile device for fieldwork. It is portable and has a dedicated camera to quickly capture an interesting finding on a specimen and to support data sharing using a QR code. More and more mobile devices are now rated IP67 or IP68, which means they resist dust and water.
If your budget allows, a tablet with a protective case, a wireless keyboard, and two 25,000 mAh power banks is a good starting point. If you limit camera and GPS use on the device, that package is sufficient for at least three weeks of fieldwork without access to electricity.
- A small tablet is the better tablet. It holds a smaller battery than a full-size one while returning comparable runtime, so a given power bank yields more recharges.
- Bring a keyboard. It speeds entry and keeps dirty hands off the screen. Many NAHPU forms move between data fields with the tab key.
- Keep your phone as the emergency plan, in case the tablet breaks in the field. Regularly send a project export to the phone. If the tablet fails, you can continue collecting records on the phone.
- Install and test before you leave. Both the tablet and the phone should carry the latest version of NAHPU, tested.
For the devices that team members have taken into the field, with days and specimen counts, see Device Requirements.
Power bank size and storage
Section titled “Power bank size and storage”Storage is driven by media, not by records. A NAHPU database uses only a few megabytes for a thousand records. What grows is the number and resolution of the images, video, and audio attached to them. As an example, a NAHPU database holding 230 high-resolution images taken with an iPhone and a dedicated 16 MP camera, and no video, takes approximately 820 MB. A 16 GB flash drive therefore carries many full backups of a season at that scale, and you always have the option to delete old backups.
Measure battery life with a realistic session. An iPad Mini 6 and a comparable Android tablet, used strictly for data collection with reduced screen brightness and limited camera use, lasted at least five days on one charge. Photography, location capture, and exports all shorten that, so run a representative NAHPU session that includes them before setting a charging schedule.
Estimate recharges from usable capacity, not from the number printed on the power bank. Power banks lose energy as heat during transfer; 60% is a commonly quoted industry-standard efficiency, and manufacturers publish their own figures.
We recommend a power bank with a USB-C connector. A 25,000 mAh unit with USB-C reaches full in about 4 hours, while a 20,000 mAh unit with micro-USB can take 8 hours or more. Carry a multi-output charger of at least 65 W, ideally one with switchable plugs for international fieldwork.
Protect batteries and equipment from heat and cold
Section titled “Protect batteries and equipment from heat and cold”Keep devices and power banks in an ideal temperature range. Apple and Samsung both rate their phones and tablets for ambient temperatures between 0 °C and 35 °C (32–95 °F), and Apple gives a storage range of −20 °C to 45 °C (−4–113 °F). Lithium-ion cells should only be charged above freezing. Carry batteries inside the pack, charge in shade, and let a hot device cool before charging it. A power bank strapped to the outside of a pack in full sun or in a steaming tent is losing capacity you will want in week two.
Cold drains capacity too, and charging a freezing battery can damage it. At a high-elevation camp or on a cold night, keep the device and power banks insulated inside the pack rather than exposed, and let them warm up before charging. A battery that looks dead in the cold often recovers once it is warm, so warm it first before concluding that it failed.
Warm batteries away from your body. A damaged or swollen lithium cell can vent or catch fire, so do not sleep with a power bank in your sleeping bag and do not keep one against your skin. Use an insulated pouch, or an outer pocket while you are awake and can notice a problem. Inspect cells for swelling, dents, or damaged cables before each trip, and retire any that look damaged.
Use protection matched to the weather, handling, and transport you expect in your fieldwork. Inspect charging ports and cables before use, and protect backup media separately.
Test offline operation
Section titled “Test offline operation”Load required taxa, presets, fonts, and reference files before departure. Rehearse without internet and check which maps or external resources are actually available. A visible map during preparation does not establish that all needed areas will be available offline.
Grant the required permissions and review location readings at the collecting position. Restore connectivity when needed for manual transfers or backup uploads. NAHPU does not automatically synchronize project edits between devices, so confirm the receiving copy before considering a transfer complete.
References
Section titled “References”Apple. If your iPhone or iPad gets too hot or too cold. Operating and storage temperature ranges for iPhone and iPad.
Samsung. Keep your Galaxy device at its normal operating temperature. Normal operating range for Galaxy phones and tablets.
Follow the current device-specific guidance: Apple cleaning instructions and Samsung cleaning instructions. For preparation and recovery, see App Setup; for choosing a device against the workflow you will run, see Device Requirements.