PA5024U-1BRS 10.8V 47.5Wh Toshiba Satellite C855 L855 Series Battery — Factory-Direct Supply

Q1: PA5024U-1BRS and PA5109U-1BRS are both listed for Satellite C855 units — are these interchangeable, or does the platform require a specific one?

A1: These are two distinct part numbers covering different production generations of the same chassis family. PA5024U-1BRS is the standard 47.5Wh / 4400mAh unit fitted to the original Satellite C855 and C55-A production run. PA5109U-1BRS is a later replacement identifier associated with higher-capacity packs (typically 48–58Wh depending on cell variant) introduced for the same platform in later service documentation. The BMS pinout and connector are identical between them, so either will seat physically — but the EC capacity register differs. If your service records list the original OEM P/N as PA5024U-1BRS, this unit matches the factory-declared capacity specification and will not trigger a capacity-mismatch warning on Toshiba’s Eco Charge monitor.

Q2: The original battery label shows 10.8V but some replacement listings show 11.1V — which voltage is correct for this platform?

A2: Both designations refer to the same physical cell architecture. A 3-series 18650 Li-ion pack has a nominal voltage of 10.8V and a fully charged open-circuit voltage of approximately 12.6V; 11.1V is an alternate nominal rounding used by some OEM documentation and aftermarket suppliers for the same cell configuration. The Satellite C/L series EC accepts both labels without error. This production unit is rated and labeled at 10.8V in alignment with Toshiba’s original PA5024U-1BRS OEM specification.

Q3: Does the PA5024U-1BRS fit Dynabook Satellite B352 units sold in Japan — or only the global Satellite series?

A3: The Dynabook Satellite B352 series uses the same battery bay geometry and connector pinout as the global Toshiba Satellite C/L series from the same 2012–2013 production period. The B352 was Toshiba’s Japan-domestic commercial education model; the battery cavity and BMS communication protocol are identical to the Satellite C850/L850 platforms. PABAS260 and PABAS262 — both covered by this stock line — appear in Dynabook’s own Japanese service documentation for the B352/W2 series.

Q4: After installing a PA5024U-1BRS, the Toshiba Power Saver utility shows “Unknown Battery” — what does this indicate and how is it resolved?

A4: The “Unknown Battery” status in Toshiba Power Saver occurs when the SMBus manufacturer string stored in the BMS EEPROM does not match the string the EC expects during the initial handshake. This is a firmware-level identifier check, not a capacity or voltage issue — the battery will still charge and discharge normally. To clear the flag: shut down the laptop, disconnect AC, remove the battery, hold the power button for 15 seconds, reinsert the battery, reconnect AC, and boot. This resets the EC’s battery learning register. If the flag persists after two reset cycles, a BIOS update to the latest revision (available from Dynabook/Toshiba support) resolves the SMBus string comparison on most affected C855 and L855 units.

Q5: We run a multi-brand repair depot and want to stock PA5024U-1BRS alongside Dell and HP battery SKUs on a single order — is that possible, and what should we submit?

A5: As a factory-direct supplier, we handle mixed-brand replenishment orders within a single shipment without requiring separate purchase orders per brand. A depot stocking PA5024U-1BRS alongside Dell and HP SKUs can consolidate those lines into one order submission. There is no minimum quantity per individual SKU — the low MOQ applies to the total order, not to each line item. To receive a consolidated quote, submit your full SKU list with target quantities per line; we will return a single price sheet with lead time confirmation.

Q6: What is the PA5024U-1BRS’s compatibility boundary with the Satellite C55 sub-families — specifically C55-A versus C55-B and C55-C?

A6: The compatibility boundary falls between C55-A and C55-B. The C55-A series uses an external snap-in PA5024U-1BRS battery with exposed locking rails. Starting with C55-B and C55-C, Toshiba redesigned the chassis to an internal non-removable battery format incompatible with PA5024U-1BRS. A procurement manager sourcing for a mixed C55 fleet should verify the chassis generation before ordering: C55-A units take PA5024U-1BRS; C55-B and later require platform-specific internal packs. The physical check is whether the battery bay has an external latch on the bottom panel — if there is no external latch, the unit is a C55-B or later and this P/N will not fit.