Replacing VRLA Battery with 48V LiFePO4 for a Telecom Site
The Challenge
The operator ran 120 macro base stations on 48V VRLA battery strings rated for 4-hour backup. Failure patterns were predictable: heat-degraded VRLA cells failed at 2-3 years in the hot summer months, each site needed a truck roll for replacement, and the maintenance team could not see state-of-health remotely — battery failures were discovered only when sites went down. Annual battery-related opex exceeded expectations by 60%.
The Solution
- 48V 100Ah LiFePO4 module. Drop-in VRLA form factor (19-inch rack mount), 1/3 the weight, rated 4,000+ cycles at 80% DOD
- Smart BMS with RS485/CAN. Cell-level voltage, temperature and SOC reporting to the existing NMS; active balancing
- Same 48V bus, zero site redesign. Standard rack mount and 48V DC bus matched the existing power plant; no new cabinets
- Wide-temperature charging. Charging profile validated from -20°C to +55°C for exposed outdoor cabinets
Before & After
| Metric | Before (VRLA) | After (LiFePO4) |
|---|---|---|
| Battery weight per site | 240 kg VRLA (4x 60 kg) | 80 kg LiFePO4 (66% lighter) |
| Backup duration | 4 hours (new), degrading to ~2.5h by year 3 | 4 hours sustained, flat to 4,000+ cycles |
| Replacement interval | 2-3 years, unplanned | 10+ years planned |
| Mid-life failure visibility | None — discovered on site outage | Real-time SOC/SOH via BMS telemetry |
| Maintenance visits | 2-3 truck rolls per site per battery life | 0 planned visits |
| 10-year TCO vs VRLA baseline | Baseline (including 2 replacements + labor) | -40% total cost of ownership |
Results
- Zero battery-related site outages in the first 12 months after retrofit
- Battery weight per site cut from 240 kg to 80 kg — lower cabinet loading and freight cost
- Remote SOC/SOH monitoring eliminated 2-3 unplanned truck rolls per site per battery life
- Projected 10-year TCO reduced by ~40% versus staying on VRLA (2 replacement cycles avoided)
- Site footprint unchanged: same 48V bus, same rack positions, standard 19-inch modules
Related Product
48V Telecom Battery LiFePO4 (50-200Ah) — the module used in this retrofit.
Case Study FAQ
Does LiFePO4 need a different charger or power plant?
No. XGW telecom batteries operate on the standard 48V DC bus with nominal float voltage, so existing telecom rectifiers and power plants work without modification. The BMS handles cell balancing internally.
Is the retrofit drop-in or does it need new cabinets?
Drop-in for most sites. The modules use standard 19-inch rack mounting with the same 48V bus connections, so most sites need no cabinet changes — a major cost saving of the retrofit.
How is the battery monitored remotely?
The smart BMS reports cell voltage, temperature, SOC and SOH over RS485 or CAN to the NMS/EMS. Alerts trigger at configurable thresholds, so failures are caught before they become outages.