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VB-5125 · Rack BBU Shelf

Rack battery backup for AI-density rows.

The VB-5125 is a 19-inch 3U BBU battery backup unit built on 51.2V LFP: 5.12 kWh per shelf, 100A continuous, hot-swap service and parallel scaling to fifteen shelves — rack-level ride-through without a room-scale UPS.

VB-5125 DATASHEET
Voltage51.2V (16S)
Capacity5.12 kWh (100Ah)
Chemistry21700 LFP
Continuous100A @1C
Peak200A / 10s
Cycle life≥6,000
Operating-20~60°C
CommsCAN · RS485 · SNMP
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VB-5125 rack BBU shelf front view — 19-inch 3U, 51.2V LFP
VB-5125 shelves installed as a parallel backup bay in a data-center row

FIG.01 — VB-5125 parallel backup bay · 1536x1024

In the row

From one shelf to an 80kW-class backup bay

One VB-5125 bridges a rack. Fifteen shelves run as one group and move roughly 77 kW of backup power — the 80kW class publicly shown embedded inside in-row power shelves — while every unit stays hot-swappable from the front.

  • Hot-swap any shelf without dropping the parallel group
  • Up to 15 shelves on one supervised bus
  • 19-inch 3U chassis sized for standard data-center racks
  • CAN, RS485 and SNMP hand-off to the rack management layer
VB-5125 datasheet

Full specifications

ParameterVB-5125
Form factor19" rack shelf, 3U
Nominal voltage51.2V DC (16S series)
Capacity5.12 kWh (100Ah)
Cell platform21700 LFP cylindrical
Continuous discharge100A @ 1C
Peak discharge200A for 10 s
Cycle life≥6,000 cycles @ 25°C, 80% DOD
Charge temperature0~55°C
Discharge temperature-20~60°C
Parallel scalingUp to 15 shelves
ServiceabilityHot-swap shelf replacement
CommunicationsCAN · RS485 · SNMP
Dimensions482.6 W × 132.5 H × 470 D mm (19-in, 3U)
Weight14.8 kg incl. modules
ComplianceUN 38.3 tested · IEC 62619 designed & tested · CE (DoC)
Warranty5 years

Storage down to -40°C available on the self-heating variant

Variants

Three ways to order the shelf

VB-5125 self-heating variant with heating element visible in the pack bay
-40°C option

Self-heating variant

For unheated rooms and winterized sites: extends storage to -40°C and pre-warms the pack so charging stays inside the 0~55°C window.

Ask about this variant →

VB-5125 300Ah high-capacity variant shelf
300Ah class

High-capacity variant

The same 16S 51.2V platform at 300Ah — roughly 15.4 kWh per shelf where runtime per rack unit matters more than swap weight.

Ask about this variant →

Group of VB-5125 shelves cabled as one parallel backup bay
≤15 shelves

Parallel group & bay kit

Factory-configured grouping for up to 15 shelves with shared supervision — one bay, one runtime curve, front-service everything.

Plan a bay with us →

FAQ

VB-5125 questions engineers ask first

Q1How many VB-5125 shelves can share one bus?▾
Up to 15 shelves run as one parallel group. Grouping and addressing are pre-configured at the factory, so the bay comes up as a single supervised battery rather than fifteen separate ones.
Q2Which documents ship with an order?▾
Every shipment carries the lithium transport file chain: cells are UN 38.3 tested (Test Summary on request), plus MSDS and drop-report paperwork. CE is self-declared with a DoC, and the design is tested to IEC 62619.
Q3What is the MOQ and lead time?▾
Engineering samples start from a single shelf. Module-class production runs at a 10–50 unit MOQ, with 2–4 weeks for samples and 4–8 weeks for volume. Terms are FOB Shenzhen / Ningbo; DDP for the EU and US is negotiable.

Size the bay once. Swap shelves for years.

Tell us the rack count, bus voltage and bridge-time target — we return a VB-5125 layout with shelf count, runtime math and a sample plan within 48 hours.

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