Lithium batteries for telecom sites: what changes from lead-acid
Telecom backup power has run on VRLA lead-acid for decades. Lithium iron phosphate (LiFePO4) is replacing it site by site, not because it is newer, but because three numbers on the datasheet, cycle life, footprint and weight, change the total cost of a backup string.
The datasheet numbers that actually change
FIBER OCEAN’s FO-LB LiFePO4 batteries are rated from 2,000 to 6,000 cycles depending on model, with a design life of up to 15 years, roughly three to five times a typical VRLA design life at the same depth of discharge.
Round-trip efficiency runs 92% or higher, rising to 95% on the FO-LB48205R, against the 80 to 85% typical of VRLA. Over years of daily float and discharge cycles at a solar or hybrid site, that efficiency gap compounds.
What the battery management system actually protects against
A lithium battery is only as good as the BMS watching it. Cell imbalance, over-discharge and thermal excursions are exactly what lead-acid never had to manage, and what LiFePO4 depends on managing well.
Cell balancing
Active balancing keeps every cell in the string within its safe voltage window, so the whole module ages evenly instead of being limited by its weakest cell.
Monitoring over RS485, CAN or Bluetooth
Rack and outdoor modules communicate over RS485, RS232 or CAN into the site’s DC plant or NMS; the standalone 12.8 V block (FO-LB12200) adds a Bluetooth BMS for direct app monitoring.
Protection thresholds
Over-voltage, under-voltage, over-current and over-temperature cutoffs, backed by IEC 62133 and UN38.3 compliance across the range.
Indoor rack, outdoor IP65, or standalone block
The right format depends on where the battery lives, not just how much energy it needs to hold.
| Model | Voltage | Capacity | Energy | Format |
|---|---|---|---|---|
| FO-LB48100 | 48 V | 100 Ah | 4,800 Wh | 3U 19″ rack module |
| FO-LB48150 | 48 V | 150 Ah | 7,200 Wh | 3U 19″ rack module |
| FO-LB48205R | 48 V | 205 Ah | 9,840 Wh | 4U 19″ rack module |
| FO-LB48050-O | 51.2 V | 50 Ah | 2,560 Wh | Outdoor IP65 cabinet |
| FO-LB48020-O | 51.2 V | 20 Ah | 1,024 Wh | Outdoor IP65 cabinet |
| FO-LB12200 | 12.8 V | 200 Ah | 2,560 Wh | Standalone block, Bluetooth BMS |
Indoor 48 V modules are also offered in 50, 150, 200 and 300 Ah, with 24 V in 100–200 Ah and 12 V in 100–400 Ah. The outdoor IP65 cabinets are rated −40 to +55 °C, against −20 to +55 °C indoors, the range that matters most for unconditioned TowerCo and access-site cabinets.
Four numbers that decide total cost
Cycle life
Rated at a stated depth of discharge, usually 80% for the rack and outdoor formats here. Compare cycle counts at the same DoD, not headline numbers.
Depth of discharge
80% DoD on most FO-LB models, 100% on the FO-LB12200 block, meaning more of the rated capacity is usable energy.
Round-trip efficiency
≥92% across the range, ≥95% on the FO-LB48205R, the energy actually returned per cycle of charge and discharge.
Operating temperature
−20 to +55 °C indoor, −40 to +55 °C outdoor IP65, the range that decides whether the site needs active thermal management at all.
From TowerCo cabinets to UPS energy stores
FO-LB batteries back the same DC buses and UPS frames covered in the rectifier and modular UPS guides, and pair with FIBER OCEAN’s telecom and 5G solutions across access, edge and core sites.
Lithium (LiFePO4) Batteries
Rack modules, outdoor IP65 cabinets and 12.8 V blocks with integrated BMS.
Explore Lithium BatteriesAll Batteries
LiFePO4 lithium and VRLA battery lines side by side.
See all BatteriesTelecom & 5G / TowerCo
Power, cooling and battery solutions built for telecom sites.
Explore Telecom SolutionsRelated guides
Telecom rectifier systems
The DC bus this battery string charges from and backs up.
Read the guideModular UPS
FO-LB batteries pair with modular UPS frames on shared or per-frame banks.
Read the guideAll Insights guides
Explainers on rectifier systems, UPS, cooling, batteries and micro data centers.
Browse InsightsFrequently asked questions
How long do FIBER OCEAN’s lithium batteries last?
FO-LB LiFePO4 batteries are rated from 2,000 to 6,000 cycles depending on model, with a design life of up to 15 years.
What is the difference between the indoor and outdoor lithium battery formats?
Indoor 48 V rack modules (100–205 Ah) are rated −20 to +55 °C at IP20; outdoor IP65 cabinets (FO-LB48050-O, FO-LB48020-O) are rated −40 to +55 °C for unconditioned TowerCo and access-site cabinets.
Do FIBER OCEAN lithium batteries have app monitoring?
The standalone 12.8 V block (FO-LB12200) has a Bluetooth BMS for direct app monitoring. Rack and outdoor modules communicate over RS485, RS232 or CAN into the site’s DC plant or NMS instead.
What certifications do the lithium batteries carry?
IEC 62133, UN38.3, CE and RoHS across the range.
What round-trip efficiency do the batteries achieve?
92% or higher across the FO-LB range, rising to 95% on the FO-LB48205R.
Scope your battery string
Share your site’s backup time target and environment, and our engineers will confirm the right format and capacity.