CyberPower RB1280X2B teardown

Inside
2 x 12 V 9 Ah
Wiring
24 V series
List price
$127
Cell size
151 x 65 x 94 mm
Terminal
F2
Evidence on cell count
verified

What is inside the RB1280X2B?

RB1280X2B holds two 12 V blocks wired in series rated 9 Ah, giving a 24 V bus. CyberPower publishes the cell count. Both blocks carry the same current and should be replaced together. Check the label on your old blocks before ordering a replacement.

FRONT ELEVATION: 2 x 12 V, 24 V DC BUSCELL 1tabs F2+−CELL 2tabs F2+−RED TO UPS (+)BLACK TO UPS (−)each cell 151 x 65 x 94 mmPLAN VIEW, TO SCALE: CASE FORMATS151 mm65Standard 7-9 Ah (this page)CSB HR1234WF2, 94 mm case height151 mm51Slim 6 AhCSB HR1224WF2F1, 94 mm case height90 mm705 Ah cubeCSB HR1221WF2, 102 mm case heightFASTON TAB WIDTH, ENLARGEDF1 4.75 mm / 0.187"F2 6.35 mm / 0.250"
Every ledger row for RB1280X2B
FieldValueQuoteSource
cells2Battery Quantity | 2T1 cyberpowersystems.com
cell ah9contains two 12V/9AH batteriesT1 cyberpowersystems.com
envelope mm202 x 64 x 151(mm) | 202 x 64 x 151 (mm)T1 cyberpowersystems.com
msrp usd127MSRP | $127T1 cyberpowersystems.com
cell ah conflict8RB1280X2B 12V/8AH (qtyT2 partssource.com
terminalF2SigmasTek SP12-7.5(T2) SLA Battery Replacement Set of 2 for CyberPower RB1280X2BT2 ebay.com
cells refurbups2Consists (2) Brand New High Rate Discharge 12V9A SLA BatteriesT2 refurbups.com
cell format osi5.94 x 2.56 x 3.70 in, .250 fastonCyberPower RB1280X2B Requires 2 batteries per unit | .250" faston | 5.94 x 2.56 x 3.70T2 osibatteries.com
cell ah osi7Nominal Capacity: 7AhT2 osibatteries.com

Which UPS models use the RB1280X2B?

Of the 35 models we track, RB1280X2B fits CP1500PFCLCD. That list comes from the manufacturer's pages, and they sometimes disagree with reseller listings. Where a model splits by serial number, its UPS page shows which prefix takes this cartridge, so check your label before you order.

Models on this site that use RB1280X2B
UPSRatingSerial condition
CP1500PFCLCD1500 VA / 1000 WSerial starts CR9, CXF or CQC

Which bare cells replace the RB1280X2B?

Replace RB1280X2B with two 12V 9 Ah F2 cells and reuse the factory harness. CyberPower lists 202 x 64 x 151 mm for the pack. A reseller confirms the terminal type, so no guesswork is needed. Keep the old harness, because bare cells ship without leads.

2 x Mighty Max ML9-12 12V 9Ah F2
Standard AGM, F2. The like-for-like choice.
Check Prime Price & Stock on Amazon →
2 x CSB HR1234WF2 12V 9Ah High Rate (the high-rate option)
High-rate AGM, F2. Holds up best at UPS discharge rates.
Check Prime Price & Stock on Amazon →

Can LiFePO4 replace the RB1280X2B?

A 12.8 V LiFePO4 pack fits the RB1280X2B bay, but its BMS sets the limit. A 12 A BMS allows about 236 W on this 24 V bus. Series packs add volts rather than amps, and they can drift apart on the charger. Measure your real load before you buy.

2 x 12.8V 10Ah LiFePO4, F1 terminal
Listing claims a 20 A BMS and doesn't say whether that is continuous.
Check Prime Price & Stock on Amazon →
2 x F1 to F2 terminal adapters, pair (4 adapters needed)
One pair covers one cell.
Check Prime Price & Stock on Amazon →

At the listing's 20 A claim the ceiling is 394 W, and at 12 A it is 236 W. Why that matters.

How much does the RB1280X2B cost against bare cells?

RB1280X2B lists at $127. Two bare cells cost about $69.88 at a non-Amazon single-unit reference price, a saving of roughly 45%. The reference is a CSB block at one store, and it is not an Amazon price. Reusing the harness is what makes this work.

Official RB1280X2B MSRP: $127. Typical Commodity Bare-Cell Band (Non-Amazon Reference): about $69.88 for 2 x CSB HR1234WF2. Reuse your factory wire harness to save about 45% against the OEM cartridge MSRP.