AI Server BBU Market Size, Share & Forecast to 2035

The AI Server BBU Market is valued at USD 1.11 billion in 2026 and is projected to reach USD 4.36 billion by 2035, up from USD 830.40 million in 2025, a CAGR of 18.05% from 2025 to 2035 (DC Market Insights estimate). The money in this market follows one design choice: whether a hyperscaler puts lithium-ion battery backup units (BBUs) inside the AI rack instead of relying on a room-level uninterruptible power supply (UPS). Meta made that choice for its Catalina rack, a 140 kilowatt (kW) Open Rack V3 (ORv3) high-power rack that lists a battery backup unit among its parts (Meta Engineering, October 2024). Advanced Energy Solution Holding (AES-KY), a Taiwanese maker of these modules, grew 2025 revenue 59.4% to NT$16.00 billion, and one unnamed customer went from 4% to 37% of its sales (AES-KY audited 2025 financial statements, March 2026). DC Market Insights builds the 2025 figure from 4.20 gigawatts (GW) of new AI rack capacity, 48% of it shipped with in-rack BBUs, at USD 400 per kW of rack load backed. 800 V direct current (DC) rack and sidecar BBUs grow from zero to USD 1.27 billion by 2035, and the Middle East and Africa is the fastest region at 21.98% a year as Saudi Arabia and the United Arab Emirates (UAE) fill new AI campuses.

Key Market Statistics: How Big Is the AI Server BBU Market in 2026?

DC Market Insights values the AI Server BBU Market at USD 1.11 billion in 2026, 34.19% above 2025, because new AI rack capacity with in-rack backup rises from 2.02 GW to 2.84 GW in one year.

• Market size 2025: USD 830.40 million; 2026: USD 1.11 billion; 2030: USD 2.96 billion; 2035: USD 4.36 billion.
• CAGR 2025-2035: 18.05% in the base case; the 2035 range runs from USD 3.23 billion (low, 14.55%) to USD 5.41 billion (high, 20.62%).
• Price: about USD 400 per kW of rack load backed in 2025, falling to USD 215 by 2035 as backup time shortens (DC Market Insights estimate).
• Largest cell chemistry: high-rate nickel manganese cobalt (NMC) and nickel cobalt aluminium (NCA) lithium-ion cells, USD 697.54 million or 84.0% of 2025 value.
• Fastest chemistry: sodium-ion and lithium titanate cells, 41.22% a year; lithium iron phosphate (LFP) reaches USD 1.18 billion by 2035.
• 800 V DC rack and sidecar BBUs: zero in 2025, USD 1.27 billion by 2035, 29.0% of the market.
• BBU module replacement grows from USD 24.00 million in 2025 to USD 1.76 billion by 2035 as the first large AI fleets reach their battery refresh.
• Leading region: North America, USD 493.26 million (59.4%) in 2025; fastest region: Middle East and Africa, 21.98% a year.
• Largest country: United States, USD 455.06 million in 2025; fastest large country: India, 25.80% a year.
• Market leaders: AES-KY, Lite-On Technology and Delta Electronics hold about 70% of 2025 value together (DC Market Insights estimate).

Executive Summary: How Fast Is Spending on AI Server Battery Backup Units Growing?

The Global AI Server BBU Market size was valued at USD 31.20 million in 2020, reached USD 830.40 million in 2025, and is anticipated to reach USD 4.36 billion by 2035, at a CAGR of 18.05% during the forecast period.

Attribute	Value
Historical period	2020-2024
Base year	2025
Forecast period	2026-2035
Market size 2025	USD 830.40 million
Market size 2026	USD 1.11 billion
CAGR 2025-2035	18.05%
Market size 2035	USD 4.36 billion

Spending grew 92.76% a year from 2020 to 2025 from a small base: new AI rack capacity rose from 0.30 GW to 4.20 GW, and the share shipped with in-rack batteries rose from 20% to 48% as ORv3 racks spread beyond Meta. Growth slows to 18.05% a year to 2035 for two reasons in the DC Market Insights model: the price per kW falls from USD 400 to USD 215 because designs move from 240 seconds of backup to 45-90 seconds, and capacitor shelves take over the sub-second smoothing job. Replacement keeps the curve rising after 2030, when racks installed in 2025-2030 need new modules.

What Is an AI Server BBU and What Does the Market Include?

AI server BBUs were a USD 830.40 million market in 2025, counting only battery backup sold into racks that hold AI accelerators.

The AI server BBU market covers rack-level battery backup units: battery modules, the shelves and chargers that hold them, and their battery management electronics, bought for racks with graphics processing units (GPUs) or custom AI accelerators, valued at the BBU maker’s selling price.

Included: ORv3 48 V to 54 V BBU modules and shelves; higher-power 50 V shelves such as 33 kW designs; 800 V DC BBU shelves in power racks and sidecars; capacitor backup units sold in BBU slots; replacement modules for installed AI racks.

Excluded: room-level UPS batteries and battery cabinets, covered in the Data Center Battery Market; campus battery energy storage systems (BESS), flywheels and grid-scale storage, covered in the Data Center Energy Storage Market; power supply units and power shelves; BBUs in racks of general-purpose servers without accelerators.

How the segments fit together: every dollar sits once in each dimension: cell chemistry, rack power architecture, deployment (new racks or replacement) and end user. Regions and countries follow where the AI racks are installed, using the same deployment shares as the DC Market Insights accelerator model.

Why Do AI Server BBU Market Estimates Differ?

AI server BBU estimates differ by boundary; DC Market Insights puts the market at USD 1.11 billion in 2026.

Broader definitions add BBUs in every Open Rack, including storage and general compute racks, the lithium-ion cells sold to BBU makers counted a second time, UPS battery cabinets in AI halls, or campus battery energy storage, and they come out several times larger. DC Market Insights counts one sale per BBU, at the module and shelf level, only where the rack holds AI accelerators; the cell value is inside that price. All rack BBU spending in data centers, AI and non-AI, was about USD 2.33 billion in 2025 in the DC Market Insights Data Center Battery Market model, so AI racks were about 36% of rack BBU spending. Buyers in scope range from hyperscale cloud providers to GPU cloud providers, colocation tenants and enterprises with small AI clusters.

Element	In this estimate	Why
BBU modules and shelves in AI racks (48 V to 54 V)	Yes, USD 830.40 million in 2025	Core product of the market
800 V DC rack and sidecar BBU	Yes, USD 1.27 billion by 2035	Same backup role in the next power design
Capacitor backup units in BBU slots	Yes, USD 24.91 million in 2025	Bought instead of a BBU for short holdup
BBUs in non-AI server racks	No	No AI accelerator in the rack
Room UPS batteries and campus BESS	No	Facility storage, covered in separate reports
Cells sold to BBU makers	No (inside module price)	Counting them again would double count

Market Drivers: Why Are Hyperscalers Putting Batteries Inside AI Racks?

AI server BBU spending rises 34.19% in 2026 because three forces push batteries into the rack at once.

Meta’s 140 kW Catalina Rack Ships with an ORv3 Battery Backup Unit

Meta’s Catalina design for NVIDIA GB200 systems uses the ORv3 high-power rack at up to 140 kW and lists a battery backup unit as part of the rack, according to Meta Engineering (October 2024). An ORv3 BBU module delivers 3 kW for 4 minutes, and a shelf of six modules runs 15 kW for more than 240 seconds with one spare module, according to the Open Rack V3 specifications written by Meta and Delta Electronics (OCP Open Rack V3 48V BBU Module Rev 1.4, September 2023). At 120 kW per NVL72-class rack, that is eight shelves and about USD 48,000 of BBU per rack at the 2025 price in the DC Market Insights model.

AES-KY Sales Up 59.4% as One Customer Reaches 37% of Revenue

AES-KY reported 2025 revenue of NT$16.00 billion, against NT$10.04 billion in 2024, with lithium-ion battery modules at 99.7% of sales; its largest customer rose from NT$408.03 million (4%) to NT$6.00 billion (37%), and Asia revenue nearly tripled to NT$9.26 billion, according to AES-KY’s audited 2025 statements (March 2026). The company names data centers as the main source of growth in backup power demand in its 2024 annual report. Monthly filings show January to September 2026 revenue of NT$14.57 billion, up 26.27% on 2025.

Alphabet, Amazon and Meta Plan USD 130-205 Billion Each of 2026 Capital Spending

Alphabet raised its 2026 capital expenditure guide to USD 195-205 billion in July 2026, Amazon plans about USD 200 billion and Meta guides USD 130-145 billion, against USD 91.4 billion, USD 131.8 billion and USD 72.2 billion in 2025, according to the companies’ earnings releases. NVIDIA reported data center revenue of USD 89.0 billion in the quarter to July 2026, up 117%, on the Blackwell Ultra ramp (NVIDIA filing, August 2026). DC Market Insights ties BBU demand to the 5.60 GW of AI capacity commissioned in 2026, not to chip revenue directly.

Market Trends: How Is AI Rack Battery Backup Design Changing?

Three design shifts move AI server BBU value, with 800 V products reaching USD 1.27 billion by 2035.

Backup Time Falls from 240 Seconds to 45-90 Seconds

The 2022 ORv3 shelf specification asked for more than 240 seconds at 15 kW; the Mt. Diablo disaggregated power rack specification from Microsoft, Meta and Google, published by the Open Compute Project (OCP) on 8 October 2026, asks for 45 to 90 seconds at full load when a BBU is used. Lite-On Technology’s newest 50 V shelf holds 12 kW for 45 seconds. Shorter holdup cuts energy per kW by a factor of three to five, which is why DC Market Insights lowers the price from USD 400 to USD 290 per kW by 2030.

800 V BBU Shelves from Lite-On, Delta and Flex

Lite-On shows a 22 kW 3U shelf at 800 V with 60 seconds of full-power backup (Lite-On analyst meeting, July 2026); Delta Electronics showed 800 V in-row power racks of 660 kW carrying 480 kW of BBU at NVIDIA GTC in March 2026; Flex offers BBUs and capacitor backup units as options on its 800 VDC power rack for NVIDIA Vera Rubin (Flex, March 2026). DC Market Insights models 800 V rack and sidecar BBUs at 29.0% of 2035 value.

Capacitors Take the Sub-Second Job: 65 J per GPU in GB300 Power Shelves

NVIDIA filled part of the GB300 NVL72 power supply volume with 65 joules of capacitor storage per GPU, built with Lite-On, cutting peak grid demand by 30% (NVIDIA technical blog, July 2025), and its 800 VDC white paper puts capacitors below 100 milliseconds and batteries beyond about 10 seconds. Capacitor backup units in BBU slots grow from USD 24.91 million in 2025 to USD 305.54 million by 2035 in the DC Market Insights model.

Market Challenges and Restraints: What Holds Back AI Server BBU Spending?

Two restraints cap AI server BBU growth at 18.05% a year, well below the 92.76% of 2020-2025.

25% Section 301 Duty on Chinese Non-EV Lithium-Ion Batteries from 2026

The Office of the United States Trade Representative (USTR) raised the Section 301 tariff on Chinese lithium-ion non-electric-vehicle batteries (tariff line 8507.60.0020) to 25% in 2026 (Federal Register 89 FR 76581, September 2024), and opened a second four-year review in May 2026. In the United States, a USD 455.06 million market in 2025, Chinese-made modules lose their price advantage, so BBU lines sit in Taiwan, Thailand, Mexico and the United States; Lite-On said in July 2026 that its BBU lines run at full capacity (Lite-On second-quarter 2026 call, July 2026).

Room UPS Still Wins Half of AI Racks: In-Rack Attach at 48% in 2025

NVIDIA’s own GB200 NVL72 user guide describes a 120 kW rack with eight power shelves and no BBU, and NVIDIA’s 800 VDC white paper calls backup an optional role for rack storage. DC Market Insights puts the share of new AI rack kW shipped with in-rack BBUs at 48% in 2025, rising only to 68% by 2035, because colocation operators keep central UPS and battery rooms. Fire codes add cost: UL 9540A, the battery fire test method, moved to a sixth edition in March 2026, effective 1 January 2027.

Market Opportunities: Where Will New AI Server BBU Revenue Come From?

Two pools add USD 3.03 billion of 2035 value that barely existed in 2025.

800 V DC Rack and Sidecar BBU: USD 1.27 billion by 2035

Racks above 200 kW cannot stay on 54 V busbars, NVIDIA says, and 800 V power racks such as Mt. Diablo hold BBUs at 800 kW to 1.1 MW per power rack. DC Market Insights expects 800 V products to start in 2027 and reach USD 1.27 billion by 2035; a 1.1 MW power rack at 90 seconds needs about 27.5 kilowatt-hours (kWh) of delivered energy.

BBU Module Replacement: USD 1.76 billion by 2035

The ORv3 module specification sets an eight-year life, and Delta rates its shelf for 240 seconds after six years; AI racks are refreshed sooner, so DC Market Insights models a five-year module replacement cycle. Replacement grows from USD 24.00 million in 2025 to USD 1.76 billion by 2035, 53.65% a year, as the 8.18 GW of BBU-backed AI racks added in 2030 reach their refresh.

Pricing Analysis: How Much Does an AI Server BBU Cost per kW?

An AI server BBU cost about USD 400 per kW of rack load backed in 2025, or about USD 48,000 for a 120 kW rack at 240 seconds (DC Market Insights estimate).

Year	USD per kW backed	Per 3 kW ORv3 module	Per 120 kW AI rack	Typical design backup time
2020	USD 520	USD 1,560	USD 62,400	240 s
2025	USD 400	USD 1,200	USD 48,000	240 s
2026	USD 378	USD 1,134	USD 45,360	180 s
2030	USD 290	USD 870	USD 34,800	90 s
2035	USD 215	USD 645	USD 25,800	60 s

Public price anchors are thin because suppliers do not disclose BBU prices. AES-KY’s gross margin of 37.61% in the first half of 2025, from its July 2025 investor presentation, shows a product priced well above its cell cost: an ORv3 module holds 66 cells of the 18650 size in an 11-series, 6-parallel pack, about 22 cells per kW. Lite-On said in April 2026 that whole power racks sell for about USD 100,000-200,000 each, a level above power supply units and BBUs. DC Market Insights keeps the same USD 400 per kW 2025 anchor as its Data Center Battery Market model, so the two estimates reconcile.

Which Specifications, Safety Tests and Battery Laws Apply to AI Server BBUs?

Seven documents shape an AI server BBU sold in 2026, starting with the OCP specifications behind the USD 830.40 million of 48 V to 54 V shelves sold in 2025.

• OCP Open Rack V3 BBU Shelf Rev 1.1 (September 2022) and BBU Module Rev 1.4 (September 2023): 3 kW modules, six per shelf with 5+1 redundancy, 240 seconds at 15 kW, eight-year life; the shelf list requires UL 1973, IEC 62133, IEC 62368-1, UL 9540 and UL 9540A reports.
• OCP Mt. Diablo Disaggregated Power Rack v1.0.0 (October 2026): BBU or capacitor bank storage in the power rack, 45-90 seconds at 100% load.
• UL 9540A sixth edition (March 2026): the cell-to-installation fire propagation test, effective 1 January 2027; NFPA 855, the National Fire Protection Association standard for energy storage, names it as the test method in its 2026 edition.
• IEC 62619:2022: safety of industrial lithium cells and batteries, including UPS use; added to the ORv3 module specification.
• UN 38.3 (UN Manual of Tests and Criteria, Rev. 8, Amendment 1, September 2025): transport tests for each module shipped.
• EU Battery Regulation (EU) 2023/1542: a battery passport from 18 February 2027 for industrial batteries above 2 kWh. A single ORv3 module holds about 0.36 kWh and sits below the line, but 800 V sidecar packs of tens of kWh do not.
• US Section 301 tariffs: 25% on Chinese non-EV lithium-ion batteries from 2026, under review since May 2026.

Market Segmentation: Which AI Server BBU Types Take the Most Spend?

High-rate NMC and NCA lithium-ion BBUs took 84.0% of 2025 spending, USD 697.54 million of USD 830.40 million.

By Cell Chemistry

High-rate cylindrical cells hold the market because a BBU must discharge at 15-20 times its capacity for a few minutes; Molicel says its S Series cells give over 1.5 minutes of backup with a six-year retention period. LFP gains share to 27.0% by 2035 as cell makers move high-power cylindrical lines toward BBU.

Cell chemistry	2025 (USD million)	Share 2025	2035 (USD million)	CAGR 2025-2035
High-Rate NMC and NCA Lithium-Ion	USD 697.54 million	84.0%	USD 2,618.90 million	14.14%
Lithium Iron Phosphate	USD 99.65 million	12.0%	USD 1,178.51 million	28.02%
Sodium-Ion and Lithium Titanate	USD 8.30 million	1.0%	USD 261.89 million	41.22%
Supercapacitor and Hybrid Capacitor Modules	USD 24.91 million	3.0%	USD 305.54 million	28.49%

By Rack Power Architecture

All 2025 value sat in 48 V to 54 V shelves; 800 V products start in 2027 and reach 29.0% of value by 2035.

Rack power architecture	2025 (USD million)	Share 2025	2035 (USD million)	CAGR 2025-2035
48 V to 54 V In-Rack BBU Shelves	USD 830.40 million	100.0%	USD 3,099.04 million	14.08%
800 V DC Rack and Sidecar BBU	USD 0.00 million	0.0%	USD 1,265.80 million	new from 2027

By Deployment

New AI rack installations were 97.1% of 2025 value; replacement reaches 40.3% by 2035.

Deployment	2025 (USD million)	Share 2025	2035 (USD million)	CAGR 2025-2035
New AI Rack Installations	USD 806.40 million	97.1%	USD 2,605.28 million	12.44%
BBU Module Replacement	USD 24.00 million	2.9%	USD 1,759.56 million	53.65%

By End User

Hyperscale cloud providers bought 68.0% of 2025 value; GPU cloud and neocloud providers grow 21.13% a year as they adopt ORv3-style racks.

End user	2025 (USD million)	Share 2025	2035 (USD million)	CAGR 2025-2035
Hyperscale Cloud Providers	USD 564.67 million	68.0%	USD 2,487.96 million	15.99%
GPU Cloud and Neocloud Providers	USD 141.17 million	17.0%	USD 960.26 million	21.13%
Colocation and Enterprise AI Deployments	USD 83.04 million	10.0%	USD 611.08 million	22.09%
Sovereign and Research AI Facilities	USD 41.52 million	5.0%	USD 305.54 million	22.09%

DC Exclusive: AI Rack Backup Teardown, from 1 kWh per Shelf to 27.5 kWh per Power Rack

DC Market Insights built this teardown from seven published BBU designs, converting each into energy, cell count and 2025 value: a 120 kW AI rack on ORv3 shelves holds about 8 kWh and USD 48,000 of BBU.

Design	Backup power	Backup time	Energy delivered	18650-class cells at 22 per kW	Value at USD 400 per kW
OCP Open Rack V3 BBU module (Meta spec Rev 1.4, 2023)	3 kW	240 s	0.20 kWh	66	USD 1,200
OCP Open Rack V3 BBU shelf, 6 modules, 5+1 (Rev 1.1, 2022)	15 kW	240 s	1.00 kWh	330	USD 6,000
Delta 33 kW BBU shelf, 50 V, 6 x 5.5 kW	33 kW	90 s	0.82 kWh	726	USD 13,200
Lite-On 12 kW 2U BBU shelf, 50 V	12 kW	45 s	0.15 kWh	264	USD 4,800
Lite-On 22 kW 3U BBU shelf, 800 V	22 kW	60 s	0.37 kWh	484	USD 8,800
120 kW NVL72-class rack on ORv3 shelves (8 shelves)	120 kW	240 s	8.00 kWh	2,640	USD 48,000
Mt. Diablo power rack, 1.1 MW at 90 s (OCP v1.0.0, 2026)	1,100 kW	90 s	27.50 kWh	24,200	USD 440,000

The teardown shows why value per kW falls even as racks grow. At 240 seconds a kW of backup needs 0.067 kWh delivered; at 45 seconds it needs 0.0125 kWh. Cell count per kW stays near 22 only because suppliers move to higher-power cells, so cost per kW falls more slowly than energy per kW. Energy and cell columns are DC Market Insights calculations from the published power and time ratings; the value column uses the 2025 model price for every design, including the 800 V power rack.

Regional Insights: Where Are AI Server BBUs Installed?

North America led with USD 493.26 million, 59.4% of 2025 value, and the Middle East and Africa grows fastest at 21.98% a year.

North America

North America grows from USD 493.26 million in 2025 to USD 2.40 billion by 2035, 17.15% a year. Meta, Microsoft and Google wrote the ORv3 and Mt. Diablo specifications, and Amazon alone plans about USD 200 billion of 2026 capital spending.

Asia Pacific

Asia Pacific grows from USD 204.28 million to USD 1.12 billion, 18.52% a year. It is also the supply base: AES-KY’s Asia revenue rose from NT$3.25 billion in 2024 to NT$9.26 billion in 2025, and Panasonic expects data center sales to rise from JPY 322 billion in the year to March 2026 to JPY 550 billion in the year to March 2027 (Panasonic, May 2026).

Europe

Europe grows from USD 76.40 million to USD 436.48 million, 19.04% a year. From 18 February 2027 the EU Battery Regulation adds a QR code to every battery and a passport to packs above 2 kWh.

Middle East and Africa

The Middle East and Africa grows from USD 40.69 million to USD 296.81 million, 21.98% a year, the fastest rate, as Saudi Arabia (22.47%) and the UAE (22.41%) fill new AI campuses.

Latin America

Latin America grows from USD 15.78 million to USD 113.49 million, 21.81% a year, from AI clusters in Brazil, Mexico and Chile.

Which Countries Spend Most on AI Server BBUs?

The United States spent USD 455.06 million on AI server BBUs in 2025, 54.8% of the market; India is the fastest large country at 25.80% a year.

Rank	Country	Region	2025 (USD million)	2035 (USD million)	CAGR 2025-2035
1	United States	North America	USD 455.06 million	USD 2,199.88 million	17.07%
2	China	Asia Pacific	USD 92.17 million	USD 392.84 million	15.60%
3	Canada	North America	USD 38.20 million	USD 200.78 million	18.05%
4	Japan	Asia Pacific	USD 29.06 million	USD 148.40 million	17.71%
5	South Korea	Asia Pacific	USD 19.10 million	USD 109.12 million	19.04%
6	United Kingdom	Europe	USD 19.10 million	USD 100.39 million	18.05%
7	India	Asia Pacific	USD 14.95 million	USD 148.40 million	25.80%
8	Saudi Arabia	Middle East and Africa	USD 14.95 million	USD 113.49 million	22.47%
9	Germany	Europe	USD 14.95 million	USD 82.93 million	18.69%
10	United Arab Emirates	Middle East and Africa	USD 13.29 million	USD 100.39 million	22.41%
11	Australia	Asia Pacific	USD 12.46 million	USD 69.84 million	18.81%
12	France	Europe	USD 10.80 million	USD 65.47 million	19.75%

China ranks second with USD 92.17 million in 2025 but grows a slower 15.60% a year because export controls limit its access to the newest accelerator racks.

Forecast Scenarios: How Large Could the AI Server BBU Market Be by 2035?

The 2035 AI server BBU market ranges from USD 3.23 billion to USD 5.41 billion around a base of USD 4.36 billion.

Scenario	2035 (USD million)	CAGR 2025-2035	Assumption
Low	USD 3,229.98 million	14.55%	In-rack attach stays near 50% and capacitor units replace batteries for holdup under 30 seconds
Base	USD 4,364.84 million	18.05%	Attach rises to 68%, USD 215 per kW in 2035, five-year replacement
High	USD 5,412.40 million	20.62%	800 V power racks standardise battery backup and diesel reduction programmes lengthen holdup

Who Are the Leading AI Server BBU Makers?

AES-KY, Lite-On Technology and Delta Electronics held about 70% of the USD 830.40 million 2025 market together (DC Market Insights estimate, based on AES-KY’s reported revenue and Lite-On’s stated BBU share).

• Advanced Energy Solution Holding (AES-KY)
• Lite-On Technology
• Delta Electronics
• Dynapack International Technology
• Simplo Technology
• Panasonic Energy
• LG Energy Solution
• Samsung SDI
• E-One Moli Energy (Molicel)
• Flex
• Infineon Technologies
• Murata Manufacturing
• EVE Energy

AES-KY’s 2025 revenue of NT$16.00 billion, about USD 500.03 million at NT$32 per US dollar, is almost all lithium-ion battery modules, and DC Market Insights attributes about USD 330 million of it to AI rack BBUs, about 40% of the market. Lite-On said BBUs will be close to 20% of its cloud segment in 2026 while the segment grows about 70%. Delta sells a 33 kW 50 V BBU shelf that runs 24 kW for 240 seconds after six years, plus a supercapacitor power capacitance shelf rated 20 kW for 15 seconds. Cell makers supply the modules: LG Energy Solution plans full-scale production of high-power tabless 2170 cells for BBU in the second half of 2026, and Samsung SDI credited BBUs and UPS batteries for AI data centers in its second-quarter 2026 results. Infineon Technologies publishes a 12 kW BBU reference design built from 3 kW power boards.

What Has Changed Recently for AI Server BBUs?

Seven dated events since March 2026 point to higher-power and 800 V BBUs in a market worth USD 1.11 billion in 2026.

• In October 2026, OCP published the Mt. Diablo Disaggregated Power Rack Specification v1.0.0 with BBU holdup of 45-90 seconds at full load (Source: Open Compute Project).
• In October 2026, Microsoft described Mt. Diablo sidecars with optional energy storage and open requirements for backup with less diesel (Source: Microsoft Azure).
• In July 2026, Lite-On said BBUs would be close to 20% of its cloud segment in 2026 and that two new cloud customers take mostly BBU shipments (Source: Lite-On Technology).
• In July 2026, LG Energy Solution set full-scale production of high-power tabless 2170 cells for BBU in the second half of 2026 (Source: LG Energy Solution).
• In May 2026, Panasonic raised its data center sales plan to JPY 550 billion for the year to March 2027 and JPY 950 billion for the year to March 2029 (Source: Panasonic Holdings).
• In March 2026, Delta Electronics showed 660 kW 800 V in-row power racks with 480 kW of BBU at NVIDIA GTC (Source: Delta Electronics).
• In March 2026, UL published the sixth edition of UL 9540A, effective 1 January 2027 (Source: UL Standards and Engagement).

Key Takeaways

Four AI server BBU findings matter most, starting from a USD 1.11 billion market in 2026.

• 2026 market size: USD 1.11 billion, up 34.19%, because BBU-backed AI rack capacity rises from 2.02 GW to 2.84 GW.
• 800 V DC Rack and Sidecar BBU reaches USD 1.27 billion by 2035, because racks above 200 kW leave 54 V busbars.
• BBU Module Replacement reaches USD 1.76 billion by 2035, because the AI fleets of 2025-2030 reach their battery refresh.
• Price per kW falls 46% to USD 215 by 2035, because backup time falls from 240 seconds to 45-90 seconds.

Research Methodology: How Did DC Market Insights Size the AI Server BBU Market?

DC Market Insights sized AI server BBUs bottom-up at USD 830.40 million for 2025.

The receipt: 12.0 GW of new IT capacity worldwide in 2025 x 35% AI share = 4.20 GW of AI racks; x 48% shipped with in-rack BBUs = 2.02 GW; x USD 400 per kW = USD 806.40 million; plus replacement of the 0.06 GW of BBU-backed AI racks installed in 2020 at the 2025 price = USD 24.00 million; total USD 830.40 million. The capacity, AI-share and price inputs are the same as in other DC Market Insights models, including the Data Center Battery Market and the AI Server Market; the Data Center Power Supply Unit Market covers the power shelves beside the BBUs.

Three bound checks hold. First ceiling: USD 830.40 million is 0.43% of NVIDIA’s USD 193.7 billion data center revenue for fiscal 2026. Second ceiling: it is 36% of the USD 2.33 billion of all rack BBU spending in the DC Market Insights Data Center Battery Market model, consistent with a 35% AI share of new capacity and a higher attach rate in AI racks. Floor: AES-KY’s 2025 battery module revenue of NT$15.95 billion, about USD 498 million, is mostly data center backup, and with Lite-On, Delta and Dynapack added the market cannot be under about USD 0.6 billion. Full method notes are on the research methodology page.