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865438-B21: HPE 800W Flex Slot Titanium Hot Plug Low Halogen Power Supply Kit

HPEPower suppliesHPE Flex Slot hot-plug edge connector

Also listed as: 865438-001, 866793-001, 865435-001, DPS-800AB-35 A · made by Delta Electronics

An ultra-high-efficiency 800-watt hot-pluggable power supply certified for 80 PLUS Titanium efficiency (up to 96% efficiency) in the standardized HPE Flexible Slot physical form factor. Designed for enterprise datacenters with strict power usage effectiveness (PUE) targets and high thermal density, it requires high-line AC input (200V-240V). On the secondary market, ensure the module includes official HPE digitally signed firmware so iLO reports accurate energy telemetry, and check the card-edge contacts for damage.

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Specifications

Part number865438-B21
BrandHPE
Made byDelta Electronics
TypePower supplies
Other numbers865438-001, 866793-001, 865435-001, DPS-800AB-35 A
Statuscurrent
InterfaceHPE Flex Slot hot-plug edge connector
Form factorFlex Slot
Tdp (W)800
Generation fitProLiant Gen10 / Gen10 Plus / Gen11 servers

About the 865438-B21

865438-B21 is HPE's 800W Flex Slot Titanium Hot Plug Low Halogen Power Supply Kit. Certified for 80 PLUS Titanium efficiency (achieving up to 96 percent electrical conversion efficiency), it represents HPE's highest-efficiency power supply option in the 800-watt class. Designed specifically for enterprise hyperscale datacenters, colocation facilities with aggressive Power Usage Effectiveness (PUE) mandates, and high-density virtualization nodes, it drastically reduces server waste heat and parasitic facility cooling overhead while maintaining tool-less N+1 or N+N redundancy.

Compatibility

This power supply is compatible with all HPE Flexible Slot bays across ProLiant Gen10, Gen10 Plus, and Gen11 rack and tower servers, including the DL360, DL380, DL385, DL560, and ML350 series. NOTE: Operating at Titanium efficiency requires high-line electrical input of 200V to 240V AC; it will NOT operate on standard 110V/120V low-line utility lines. It connects using a standard IEC 60320 C13 power cable. Both power supplies in a redundant server pair must share identical wattage and Titanium efficiency ratings; mixing Platinum and Titanium supplies is unsupported. The option part is 865438-B21, with spare number 866793-001 and generic number 865435-001.

How to identify a genuine unit

A genuine 865438-B21 unit carries an authentic HPE label showing option part number 865438-B21, spare number 866793-001, generic part number 865435-001, and the prominent blue-and-white 80 PLUS Titanium efficiency logo. Inside iLO 5 or iLO 6 under Power Management, the module reports as an authenticated Titanium-grade power supply with active power capping telemetry, temperature sensors, and firmware version verification. Counterfeit units or non-HPE Delta OEM supplies will report unauthenticated status in iLO.

Buying used

When evaluating second-hand Titanium power supplies, inspect the rear gold card-edge connector for scratches, pitting, or carbon scorching caused by live hot-plug arc discharge. Spin the internal high-CFM cooling fan by hand to ensure free, whisper-quiet rotation without bearing drag. Crucially, verify that your datacenter or lab environment provides 208V-240V AC PDU receptacles, as this power supply will not power on when plugged into standard 110V utility circuits.

Reference prices (last 14 days, updated 2026-10-27)

New: USD 189 (1 sighting, Oct 2026)

Refurbished: USD 76 (1 sighting, Oct 2026)

All sightings
SellerConditionPriceNoteSeen
serversupply.comrefurbishedUSD 76seller refurbished / tested2026-10-27
storagepartsdirect.comnewUSD 189brand new in box2026-10-27

Prices seen on public listings on the dates shown, before tax and shipping. Not an offer.

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FAQ

Does 865438-B21 work on 110V utility power?

No. The 800W Flex Slot Titanium power supply strictly requires high-line AC input between 200V and 240V AC. It will not power on on 110V-120V low-line circuits.

What is the efficiency advantage of Titanium over Platinum?

80 PLUS Titanium achieves up to 96% efficiency (versus 94% on Platinum) and maintains high efficiency even at low loads (10% load), saving significant power in idle and lightly loaded states.

Buying or selling 865438-B21?

New, refurbished or used. Tell us the quantity and condition and we connect you with a vetted reseller in your region, usually within one working day.

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