Rated Service Life
| Sensor Family | Chemistry | Typical Life | Notes |
|---|---|---|---|
| FX (external) | CR2450 Li | 5–7 years | Reduced 20% below 0°F ambient |
| LINK (internal) | Non-replaceable Li-SOCl2 | 7–10 years | Replace entire sensor at EOL |
| Legacy PPS Gen 2 | CR2032 Li | 3–4 years | Discontinued in 2023 |
Health Reporting
Every sensor transmits a battery health byte on each 60-second heartbeat. The fleet console surfaces four states:
- Healthy — > 2.85 V
- Watch — 2.65–2.85 V
- Replace — 2.50–2.65 V
- Critical — < 2.50 V
Recommended Practice
Schedule FX battery replacement during regular tire rotation once any sensor on the asset reads 'Watch'. Replacing in batches reduces truck downtime and eliminates asymmetric drift across the axle.