CyberPower RB1290X3L teardown

Inside
3 x 12 V 9 Ah
Wiring
36 V series
List price
$220
Cell size
151 x 65 x 94 mm
Terminal
F2
Evidence on cell count
verified

What is inside the RB1290X3L?

RB1290X3L holds three 12 V blocks wired in series rated 9 Ah, giving a 36 V bus. CyberPower publishes the cell count. All the blocks carry the same current and should be replaced together. Check the label on your old blocks before ordering a replacement.

FRONT ELEVATION: 3 x 12 V, 36 V DC BUSCELL 1tabs F2+−CELL 2tabs F2+−CELL 3tabs 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 RB1290X3L
FieldValueQuoteSource
cells3Battery Quantity | 3T1 cyberpowersystems.com
cell ah9Battery Size | 12 V / 9 AhT1 cyberpowersystems.com
envelope mm333 x 193 x 81(mm) | 333 x 193 x 81 (mm)T1 cyberpowersystems.com
msrp usd220RB1290X3L | $ 220.00T1 cyberpowersystems.com
bus v36BP36V60ART2UT1 cyberpowersystems.com
terminalF2OL1500RTXL2U 12V 9Ah UPS Battery; Voltage: 12V (12 Volts); Capacity: 9Ah; Terminals: F2T2 amazon.ca

Which UPS models use the RB1290X3L?

Of the 43 models we track, RB1290X3L fits OL1500RTXL2U. 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 RB1290X3L
UPSRatingSerial condition
OL1500RTXL2U1500 VA / 1350 Wall serials

Which bare cells replace the RB1290X3L?

Replace RB1290X3L with three 12V 9 Ah F2 cells and reuse the factory harness. CyberPower lists 333 x 193 x 81 mm for the pack. The terminal comes from a retailer cross-reference or inference, so check your old cell first. Keep the old harness, because bare cells ship without leads.

3 x Mighty Max ML9-12 12V 9Ah F2
Standard AGM, F2. The like-for-like choice.
Check Prime Price & Stock on Amazon →
3 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 RB1290X3L?

We can't recommend LiFePO4 for RB1290X3L. Three independent BMS boards in one 36 V series string multiply the balance risk on this online double-conversion UPS. Showing a link would mean guessing about fit. Buy the lead-acid cell or a factory LiFePO4 UPS instead, and see our method page for how we test fit.

How much does the RB1290X3L cost against bare cells?

RB1290X3L lists at $220. Three bare cells cost about $104.82 at a non-Amazon single-unit reference price, a saving of roughly 52%. The reference is a premium CSB block at one store, and it is not an Amazon price. Reusing the harness is what makes this work.

Official RB1290X3L MSRP: $220. Typical Commodity Bare-Cell Band (Non-Amazon Reference): about $104.82 for 3 x CSB HR1234WF2. Reuse your factory wire harness to save about 52% against the OEM cartridge MSRP.