What Battery Is Used for Telecom Towers?
Most telecom towers run on a -48V DC plant backed by batteries. Historically sealed lead-acid (VRLA) did the job; today 48V LiFePO4 battery packs are the standard upgrade for longer life, less weight and lower total cost.
The Short Answer
A telecom tower (BTS / base transceiver station) is powered by a -48V DC distribution plant, and the batteries sit on that bus to ride through grid outages and the gaps between generator starts. The two chemistries you will meet are:
- VRLA (valve-regulated lead-acid) — the legacy choice
- LiFePO4 (lithium iron phosphate) — the modern upgrade
Most new builds and retrofits now specify 48V LiFePO4.
Why Telecom Uses -48V, Not +48V
The -48V standard comes from old telephone-exchange practice: a positive-grounded 48V bus is safer for technicians and resists galvanic corrosion. The batteries are therefore a string of cells whose terminal voltage sits around -48V nominal. In a LiFePO4 pack that is 16 cells in series (16S): 16 × 3.2V = 51.2V at full charge, ~48V working.
VRLA vs LiFePO4 in a Cell Site
- Cycle life: VRLA ~300–500 cycles; LiFePO4 2000–6000+ cycles.
- Weight & footprint: LiFePO4 is roughly half the weight for the same energy, freeing rack space.
- Temperature: VRLA loses capacity fast above 30°C and needs equalisation; LiFePO4 tolerates a wider range behind a BMS.
- Total cost: VRLA is cheaper to buy, but LiFePO4 wins on 10-year TCO because it is replaced far less often.
See the detailed comparison in our LiFePO4 vs lead-acid for telecom guide and the broader LiFePO4 vs VRLA battery article.
How Big Is a Tower Battery?
A typical macro BTS load is 1–5 kW. At -48V that is roughly 20–100A. A common configuration is a 48V 100Ah–200Ah LiFePO4 pack (5–10 kWh) sized for 4–10 hours of backup before the generator or grid returns. Remote and off-grid sites add solar and larger banks.
What XGW Supplies
We build 16S 48V telecom LiFePO4 packs in rack-mount or outdoor cabinets, with a telecom-grade BMS (RS485 / CAN, dry-contact alarm) and UL / CE / CB where required. Read the 48V telecom battery guide or see a deployed telecom battery project.
Browse the Telecom Battery range, or request a quote for OEM sizing.
FAQ
Can a telecom tower run on grid power alone?
No. The batteries are the ride-through energy between a grid failure and generator start, and the sole backup for off-grid sites.
Is 48V LiFePO4 safe in a cabinet?
Yes. LiFePO4 is thermally stable and a BMS monitors every cell; the cabinet still needs ventilation and fire separation per local code.
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