Eaton 5PX Battery Replacement: Which Battery Fits Your 5PX or 5PX G2?

This guide is for IT staff and facility technicians who need to replace the internal battery in an Eaton 5PX rack/tower UPS and want to order the right pack the first time. It covers the North American 120 V models of both generations, from 1000 VA to 3000 VA, and their external battery modules (EBMs). International "i" models appear only where Eaton lists them for the same pack. It does not cover the Eaton 5P or 9PX families or lithium-ion units. Every voltage, block count and Eaton part number in Tables 1 and 2 comes from Eaton's own manuals and product pages, listed under Sources; Table 3 lists our own aftermarket products.

How to tell a first-generation 5PX from a 5PX G2

Eaton sold two generations under the 5PX name. The second generation, documented in Eaton's 5PX Advanced User Guide 614-40095-00 (2021), adds "G2" to the end of every catalogue number: 5PX1500RTNG2, 5PX2000RTG2, 5PX3000RT3UNG2 and so on [2]. The first generation, documented in manual 614-03797-00 (2010), uses catalogue numbers such as 5PX1500RT, 5PX2200RT and 5PX3000RT2U with no suffix [1][3][4][5][6]. This guide calls it the first generation; Eaton does not use the term G1.

Three ways to confirm which one you have:

• The rating label on the rear or side of the unit shows the full catalogue number. If it ends in G2, use the G2 tables below.
• The front-panel display. On a first-generation unit, the Identification menu shows the UPS type and part number [1]. On a G2, Eaton states that the recommended battery replacement date and the battery reference can be read on the LCD under Measurements > Battery [2]. That reference is the most direct answer to "which battery does this unit take".
• The extended battery module, if one is fitted. First-generation EBMs are named 5PXEBM48RT or 5PXEBM72RT2U; G2 EBMs end in G2, for example 5PXEBM48RTG2 [2][6][7].

Why the 1500 VA answer changed between generations

Answers found online disagree on whether a "5PX 1500" uses 7.2 Ah or 9 Ah blocks. Both are correct, for different units. Eaton rates the first-generation 5PX1500RT at 12 V / 7.2 Ah per block [6], while the G2 guide lists the 1500 VA models at 48 V dc, four 12 V 9 Ah blocks [2]. The string voltage is the same (48 V); the block capacity and the Eaton part differ.

A simple calculation shows what that means. Nominal stored energy is voltage times ampere-hours:

• First-generation 1500: 48 V x 7.2 Ah = 345.6 Wh
• G2 1500: 48 V x 9 Ah = 432 Wh

The G2 pack holds about 25% more nominal energy (432 / 345.6 = 1.25). Real runtime at a given load does not scale exactly with that figure, so use Eaton's published runtime data or the unit's own runtime estimate for planning. What matters for ordering is that the two packs are different parts with different Eaton references (EBP-1001 versus 744-A4801) [3][8].

First-generation 5PX: battery by model

For the original 5PX, Eaton's manual lists three internal battery configurations and Eaton's product pages give the replacement pack for each size [1][3][4][5][6].

Table 1. First-generation Eaton 5PX: internal battery, Eaton replacement pack and matching EBM. Sources [1][3][4][5][6].

Models	Internal battery	Eaton pack	EBM
5PX1000 (RT, RT2U), 5PX1500RT, 5PX1500RTN, 5PX1500RTUS, 5PX1500iRT	48 V: 4 x 12 V 7.2 Ah	EBP-1001	5PXEBM48RT
5PX2200RT, 5PX2200RTN, 5PX2200RTUS, 5PX2200iRT	48 V: 4 x 12 V 9 Ah	EBP-1002	5PXEBM48RT
5PX3000RT2U, 5PX3000RT2US, 5PX3000RTN, 5PX3000iRT2U, 5PX3000iRTN	72 V: 6 x 12 V 9 Ah	EBP-1003	5PXEBM72RT2U (listed on the 5PX3000RT2U page)
5PX 3000 RT3U	72 V: 6 x 12 V 9 Ah	Not listed on the EBP-1003 page; read the unit label	"5PX EBM 72V RT3U" (manual name)

First-generation EBMs hold two strings: the 48 V module has two strings of four 12 V 9 Ah blocks, the 72 V modules two strings of six. Up to four EBMs can be added to one UPS [1].

5PX G2: battery by model

The G2 guide gives the internal battery for each power rating, and Eaton's cartridge pages list the models each replacement cartridge is "used with" [2][7][8][9][10][11].

Table 2. Eaton 5PX G2 (120 V): internal battery, Eaton replacement cartridge and matching EBM. Sources [2][7][8][9][10][11]. The 5PX2200HRTG2, 5PX3000HRTG2 and 5PX3000HRTNG2 are not in the G2 guide; their battery is given from the cartridge Eaton lists for them.

Models	Internal battery	Eaton cartridge	EBM
5PX1000RTG2, 5PX1000RTNG2	48 V: 4 x 12 V 7 Ah	Read the reference on the LCD (Measurements > Battery)	5PXEBM48RTG2
5PX1500RTG2, 5PX1500RTNG2, 5PX1500HRTG2	48 V: 4 x 12 V 9 Ah	744-A4801	5PXEBM48RTG2
5PX2000RTG2, 5PX2000RTNG2, 5PX2200HRTG2	72 V: 6 x 12 V 7 Ah	744-A4802 or 744-A4852	5PXEBM72RTG2
5PX2000RT3UNG2	72 V: 6 x 12 V 7 Ah	744-A4802	5PXEBM72RT3UAG2
5PX3000RTG2, 5PX3000RTNG2, 5PX3000HRTG2, 5PX3000HRTNG2, 5PX3000RT3UNG2	72 V: 6 x 12 V 9 Ah	744-A4803	5PXEBM72RTG2 (2U) or 5PXEBM72RT3UAG2 (3U)

Two details trip buyers. First, Eaton lists its 72 V, six-block cartridge 744-A4802 for the G2 2200 VA unit (5PX2200HRTG2), while the first-generation 5PX2200RT runs 48 V, so the two share a power class but no battery or EBM [1][2][7][9]. Second, Eaton's G2 guide lists the 1000 VA and 2000 VA blocks as 7 Ah, while the first-generation manual and our sets use 12 V 7.2 Ah blocks; we treat the two as the same block size, which is our reading rather than an Eaton statement [1][2][12]. G2 EBMs hold two strings, like the first generation: 2 x 4 x 12 V 9 Ah at 48 V, or 2 x 6 x 12 V 9 Ah at 72 V [2].

Generations are not interchangeable

Do not move a pack between generations, even inside the same VA rating, and match EBMs to the generation: Eaton lists only G2 EBMs for G2 units and first-generation EBMs for first-generation units [1][2][6][7]. The G2 guide tells you to replace batteries "with the same type and number of batteries or battery packs" [2], and the first-generation manual asks for the same type and number of elements as the original module [1]. A 48 V pack cannot serve a 72 V unit. The first-generation manual also says to use only batteries supplied by Eaton [1], so check your UPS warranty terms before fitting non-Eaton batteries. Our aftermarket sets match the original's voltage, block count and sealed lead-acid type; the one exception is the optional 9 Ah set for the first-generation 5PX1500RT, a capacity change explained under Table 3. The choice between an Eaton pack and an aftermarket set is yours, and the Eaton part numbers above let you buy either.

Replacing the battery: what Eaton's procedure requires

For G2 units, Eaton states that the batteries can be replaced without turning off the UPS or disconnecting the load, and that you must not disconnect the batteries while the UPS is in Battery mode [2]. Eaton's cartridge pages describe 744-A4801, 744-A4802, 744-A4803 and 744-A4852 as hot-swappable and as reusing the existing wiring harness [8][9][10][11]. The G2 procedure is short [2]:

1. Pull off the front panel by pressing the tabs on both sides.
2. Disconnect the battery pack by separating the connectors; never pull on the wires.
3. Remove the metal cover in front of the battery (three screws, or two on 3U models).
4. Pull the plastic tab to slide the pack out, and fit the new one.
5. Reconnect the battery connector, observing polarity (red +, black -), then refit the metal cover and the front panel (the reverse of the steps above).

Eaton warns that reversing polarity (red +, black -) when connecting the batteries destroys the unit [2]. The first-generation procedure is similar: remove the middle panel and the left part of the front panel, separate the connectors, remove the two-screw cover and pull the tab [1]. On either generation, Eaton's safety notes apply: remove watches and rings, use insulated tools, and leave the work to people who know battery hazards [1][2]. If your 5PX feeds equipment that cannot drop, a HotSwap MBP maintenance bypass module lets the whole UPS be serviced or replaced with the load on utility power [1][2].

After the swap: charge, test, reset

• Charge before you trust the runtime. The G2 internal batteries reach 90% in under 3 hours, but Eaton recommends 48 hours of charge after long storage and at least 48 hours after a full discharge to restore full backup time [2].
• Run a battery test from the front panel once charged (Control > Start battery test on the first generation) [1].
• Check the replacement reminder. The G2 shows a battery replacement reminder after a set period, 48 months by default; the setting is in the battery menu [2].
• Spare packs on the shelf need a recharge every 6 months, per both manuals; the first-generation manual says to energize the UPS for 24 hours at least once every 6 months when stored below 25 °C [1][2].

How long a 5PX battery lasts

Eaton gives the G2 batteries a minimum 3 to 5 year float service life at 25 °C (77 °F), and the UPS warns after 4 years of operation that the batteries are nearing the end of their useful life [2]. Both generations are rated for 0 to 40 °C operation [1][2]. Eaton also notes that runtime drops below 10 °C [2], which matters for units in unheated telecom rooms or warehouses during a Canadian winter. A rack in a hot closet sits at the other end of the range. The 3 to 5 year figure is stated at 25 °C; as a general rule for sealed lead-acid batteries, rather than an Eaton figure, a warmer room shortens that life, so plan the replacement earlier.

Matching our catalogue to your 5PX

Every set below is aftermarket (not made by Eaton) and new, matched to the voltage and block count in Tables 1 and 2. "Set" pages are loose blocks that reuse your harness; "assembled pack" pages arrive wired. The full range is on the Eaton 5PX battery replacements page.

Table 3. UPSPLUSBATTERY listings for common 5PX models. Contents from each product page [12].

Your UPS	Listing	What is in the box
5PX1000RT2U (1st gen)	Replacement battery set for Eaton 5PX1000RT2U (aftermarket)	4 x 12 V 7.2 Ah
5PX1500RT (1st gen)	Replacement battery set for Eaton 5PX1500RT (aftermarket)	4 x 12 V F2 blocks. Choose 7.2 Ah to match Eaton's rating; the 9 Ah option departs from it (see note below)
5PX2200RT (1st gen)	Replacement battery set for Eaton 5PX2200RT (aftermarket)	4 x 12 V 9 Ah, reuses your wiring
5PX3000RT2U (1st gen)	Replacement battery set for Eaton 5PX3000RT2U (aftermarket)	6 x 12 V 9 Ah
5PX3000RT3U (1st gen)	Replacement battery set for Eaton 5PX3000RT3U (aftermarket)	6 x 12 V 9 Ah
5PX1000RTG2, 5PX1000RTNG2	Replacement battery set for Eaton 5PX1000RTG2 (aftermarket)	4 x 12 V 7.2 Ah (48 V), reuses your wiring
5PX1500RTG2, RTNG2, HRTG2	744A4801-compatible battery (aftermarket)	4 x 12 V 9 Ah (48 V), reuses your wiring
5PX2000RTG2, RTNG2, RT3UNG2, 2200HRTG2	744A4802-compatible battery (aftermarket)	6 x 12 V 7.2 Ah (72 V), reuses your wiring
5PX3000 G2 models	744-A4803-compatible pack (aftermarket)	Pre-wired pack, 6 x 12 V 9 Ah (72 V)

A note on the 9 Ah option for the first-generation 5PX1500RT: Eaton rates that unit at 7.2 Ah per block [6], so a 9 Ah set departs from Eaton's specification and from the "same type" instruction in its manuals [1][2]. Choose 7.2 Ah to stay on the Eaton rating. Both sizes on that product page use F2 tabs [12]; our F1 vs F2 terminal guide explains the difference if you are rebuilding a harness. If you are still choosing a UPS rather than a battery, browse Eaton 5PX UPS systems or compare against the smaller Eaton 5P rackmount range.

Checklist before you order

• Full catalogue number from the rating label, including any G2 suffix.
• On a G2, the battery reference shown under Measurements > Battery [2].
• Battery voltage: 48 V or 72 V (Tables 1 and 2).
• Whether you want loose blocks that reuse your harness or a pre-wired pack.
• Any EBMs on the same UPS: they age too, and the UPS reports how many it detects [1].
• A plan for the old batteries: sealed lead-acid batteries must go to a recycling or hazardous-waste collection point, never the trash [2].

For racks of 5PX units across several sites, or when the battery is only part of the problem, an on-site UPS battery replacement service can do the swap, test the new string and check the UPS itself.

Sources

1. Eaton, 5PX 1000-3000 RT2U/RT3U and 5PX EBM Installation and user manual, North America, document 614-03797-00 (2010): battery table (4 x 12 V 7.2 Ah, 4 x 12 V 9 Ah, 6 x 12 V 9 Ah), EBM strings, up to 4 EBMs, storage recharge every 6 months, battery-module replacement steps, use Eaton-supplied batteries, 0 to 40 °C. eaton.com (PDF)
2. Eaton, 5PX G2 Advanced User Guide, document 614-40095-00 (2021): section 8.7 battery (1000 VA 48 V 4 x 12 V 7 Ah; 1500 VA 48 V 4 x 12 V 9 Ah; 2000 VA 72 V 6 x 12 V 7 Ah; 3000 VA 72 V 6 x 12 V 9 Ah; EBM strings; 3-5 year float life at 25 °C), sections 6.2 to 6.4 (storage, 48 h charge, 4-year reminder, replacement without turning off the UPS, procedure, polarity warning), section 8.2 (EBM list). eaton.com (PDF)
3. Eaton, EBP-1001 5PX battery pack, used with 5PX1000, 5PX1500RT, 5PX1500RTN, 5PX1500RTUS, 5PX1500iRT. eaton.com
4. Eaton, EBP-1002 5PX battery pack, used with 5PX2200RT, 5PX2200RTN, 5PX2200RTUS, 5PX2200iRT. eaton.com
5. Eaton, EBP-1003 5PX battery pack, used with 5PX3000RT2U, 5PX3000RT2US, 5PX3000iRT2U, 5PX3000iRTN, 5PX3000RTN. eaton.com
6. Eaton product pages for the first-generation 5PX1000RT and 5PX1500RT (battery rating 12 V / 7.2 Ah, EBM 5PXEBM48RT), 5PX2200RT (12 V / 9 Ah, EBM 5PXEBM48RT) and 5PX3000RT2U (EBM 5PXEBM72RT2U). 5PX1500RT, 5PX2200RT, 5PX3000RT2U
7. Eaton product pages for the 5PX G2 (EBM 5PXEBM48RTG2 for 1000 and 1500 VA; 5PXEBM72RTG2 for 2000, 2200 and 3000 VA; 5PXEBM72RT3UAG2 for the 3000 RT3U). 5PX1500RTNG2, 5PX2200HRTG2, 5PXEBM48RTG2
8. Eaton, 744-A4801 internal replacement battery cartridge: used with 5PX1500RTG2, 5PX1500RTNG2, 5PX1500HRTG2 and Tripp Lite SmartPro SMART1500RMXL2U, SMART1500RMXLN, SMX1500XLRT2U, SMX1500XLRT2UN; hot-swappable; reuses existing harness. tripplite.eaton.com
9. Eaton, 744-A4802 internal replacement battery cartridge: used with 5PX2000RTG2, 5PX2000RTNG2, 5PX2000RT3UNG2, 5PX2200HRTG2. tripplite.eaton.com
10. Eaton, 744-A4803 internal replacement battery cartridge: used with 5PX3000RTNG2, 5PX3000RT3UNG2, 5PX3000HRTG2, 5PX3000RTG2, 5PX3000HRTNG2. tripplite.eaton.com
11. Eaton, 744-A4852 internal replacement battery cartridge: used with 5PX2000RTG2, 5PX2000RTNG2, 5PX2200HRTG2. tripplite.eaton.com
12. UPSPLUSBATTERY product pages listed in Table 3 (contents, block size, terminals), read 14 October 2026. upsplusbattery.ca

Written by the UPSPLUSBATTERY technical team. Published 14 October 2026. Eaton, Tripp Lite, SmartPro and HotSwap are trademarks of Eaton Corporation or its affiliates. UPSPLUSBATTERY is not affiliated with or endorsed by Eaton; part numbers are given for identification. Our sets are aftermarket.