56 Days on a Single Charge: How SMART Location Strategy Extends Battery Life

The Battery Life Problem in IoT Tracking

Location tracking is fundamentally at odds with battery life. A full GNSS fix — acquiring satellites, downloading ephemeris data, computing a position — is one of the most power-intensive operations a small embedded device can perform. A typical GNSS receiver draws 30–50 mA during acquisition, and a cold start can take 30 seconds or more. For a device running on a 6,000 mAh battery, frequent GNSS fixes drain the cell in days.

This creates a painful trade-off for operations teams. High-frequency location updates provide better visibility but require frequent field visits to swap or recharge batteries. Low-frequency updates extend battery life but create gaps in tracking coverage. For remote assets — equipment on mine sites, shipping containers in transit, vehicles in rural areas — every battery swap is a logistics operation that costs time and money.

The KA1 edge device was designed to break this trade-off. Instead of choosing between accuracy and endurance, its SMART location strategy delivers both.

The Four Location Strategies

The KA1 supports four configurable location strategies, each balancing accuracy against power consumption differently. Understanding all four provides context for why SMART is the default and why it outperforms the alternatives.

FULL — Maximum Accuracy, 35 Days

Every location fix is a full GNSS acquisition. The receiver powers on, acquires satellite signals, computes a 3D position, and shuts down. This provides the highest accuracy (typically 2–5 meter CEP) but consumes the most power. With a 6,000 mAh battery and 15-minute reporting intervals, the FULL strategy delivers approximately 35 days of operation.

THIN — Cell and Wi-Fi Positioning, 70+ Days

Instead of acquiring GNSS satellites, the device scans visible cell towers and Wi-Fi access points, then sends these identifiers to a cloud positioning service. The position is computed server-side using tower and AP databases. Accuracy is lower (50–300 meters depending on tower density) but power consumption drops dramatically. A thin scan completes in under 2 seconds and draws a fraction of the current. Battery life extends to 70 or more days.

DEFER — Skip When Stationary

The device includes a motion sensor (accelerometer). When no motion is detected, location fixes are skipped entirely. The device reports its last known position and conserves power. This is useful for assets that sit idle for extended periods — construction equipment between projects, seasonal vehicles, or stored inventory.

SMART — Adaptive, 56 Days

SMART combines the best of all three approaches. Under normal operation, 90% of location fixes use the thin (cell/Wi-Fi) method. Every 10th fix is a full GNSS acquisition for calibration. When stationary, fixes are deferred entirely. The result is 56 days of battery life with location accuracy that is sufficient for operational tracking while maintaining periodic high-accuracy calibration points.

How SMART Works in Practice

The SMART algorithm continuously adapts its behavior based on device state and motion context. Here is the decision logic that runs on each reporting interval:

First, the device checks its motion state. If the accelerometer has detected no movement since the last report, the device defers — it skips the location fix entirely and reports its last known coordinates with a “stationary” flag. No radio is activated, no scan is performed. Power draw is minimal.

If motion has been detected, the device increments a fix counter and checks whether this is a calibration interval (every 10th fix). If it is, the GNSS receiver powers on for a full satellite acquisition. This periodic calibration ensures that the device's position estimate does not drift too far from reality, even if the cell tower and Wi-Fi positioning has lower accuracy in rural areas.

For all other fixes — the remaining 90% — the device performs a thin scan. It briefly activates the cellular modem and Wi-Fi radio to scan visible towers and access points, packages the scan results, and transmits them to the cloud for server-side position resolution. The entire operation completes in 1–3 seconds.

This adaptive approach means the device is never wasting power on unnecessary precision. A shipping container sitting in a yard does not need GPS-level accuracy every 15 minutes. A vehicle in transit gets calibration fixes frequently enough to maintain accurate route reconstruction.

Power Management Deep-Dive

Battery life is not just about location strategy — it requires aggressive power management at every layer of the hardware stack. The KA1 implements several power-saving techniques beyond location optimization:

• PSM (Power Saving Mode) — Between reporting intervals, the cellular modem enters Power Saving Mode. The device is unreachable during PSM but draws only microamps. It wakes on a configurable timer to check for pending downlink messages.
• eDRX (Extended Discontinuous Reception) — For deployments that require some level of reachability between reports, eDRX allows the device to negotiate extended sleep windows with the network while remaining registered. Power consumption is higher than PSM but significantly lower than idle-connected mode.
• Force Sleep — After 30 seconds of inactivity following a transmission, the device enters a passive sleep mode. All non-essential peripherals are powered down. The accelerometer remains active as a wake source, consuming only microamps.
• NPM1300 battery management — The Nordic NPM1300 PMIC (Power Management IC) provides efficient DC-DC conversion, battery charging management, and fuel gauging. Its high-efficiency buck converter minimizes conversion losses, and the integrated fuel gauge enables accurate state-of-charge reporting back to the platform.

The combination of SMART location strategy and aggressive power management at the hardware level is what enables the 56-day figure. Neither alone would be sufficient — an efficient location strategy on wasteful hardware, or efficient hardware with a naive location strategy, would both fall short.

A-GPS: Faster Fixes, Less Power

Assisted GNSS reduces time-to-first-fix from 30+ seconds to under 5 seconds, further compounding power savings. When the SMART algorithm decides to take a full GNSS fix, the device first downloads assistance data from nRF Cloud. This data includes current satellite ephemeris and almanac information, eliminating the need for the receiver to decode this data from the satellite signals directly.

A cold-start GNSS fix — without assistance data — requires the receiver to stay powered for 30 seconds or more while it acquires and decodes satellite navigation messages. With A-GPS, the receiver already knows where satellites are and what signals to expect. Fix times drop to 2–5 seconds.

At 40 mA receiver current, the difference between a 30-second fix and a 3-second fix is substantial over thousands of fixes across the battery's lifetime. A-GPS does require a brief data download over the cellular connection, but the energy cost of downloading a few kilobytes of assistance data is far less than running the GNSS receiver for an additional 25 seconds.

Real-World Impact: The Math That Matters

56 days versus 35 days is a 60% improvement in battery life. For a single device, this means fewer field visits. For a fleet, it transforms operations.

Consider a fleet of 100 trackers deployed across remote sites. With a 35-day battery life and staggered deployment dates, the operations team performs roughly 3 battery swaps per day on average. Each swap may require a vehicle dispatch, site access coordination, and technician time. With a 56-day battery life, that same fleet requires only 1.8 swaps per day — a 40% reduction in field maintenance visits.

For truly remote deployments — mining exploration sites, offshore installations, agricultural operations — the difference is even more significant. A 56-day battery life means monthly logistics runs can service every device, rather than requiring bi-weekly visits. In some cases, the battery life aligns with existing maintenance schedules, eliminating dedicated battery swap trips entirely.

The SMART strategy also reduces cellular data usage. Thin scans produce smaller payloads than full GNSS fixes, and deferred (stationary) reports are minimal. For deployments where cellular data is metered — particularly on satellite or roaming connections — this translates to lower operating costs per device per month.