878643-001 with serial 6WQXKONWYGJ5EI is another unit of the HPE 96W Smart Storage Megacell Battery (MC96) with the 145 mm cable.

This is the exact same battery model as the previous ones you asked about:

* 876850-001

* 750450-001 (Dec 2014 build)

* 881093-210

* 878643-001

Summary of This Specific Unit

* Part Number: 878643-001 (HPE spare / LOTS number)

* Description: 96W Lithium-ion Smart Storage Battery (low-halogen), 145 mm (5.7-inch) cable

* Function: Centralized backup power for Flash Backed Write Cache (FBWC) on HPE Smart Array P-class RAID controllers (Gen9 and Gen10 ProLiant servers). It can protect up to ~20–24 devices/controllers in one server and also supports NVDIMMs.

* Serial / Trace Code: 6WQXKONWYGJ5EI — This is the unique manufacturing serial number printed on the battery label (similar format to the previous 6WQXLOGB2EW3PB you mentioned).

HPE uses the 6WQX prefix for these MC96 batteries. The remaining characters encode manufacturing details (plant, date, etc.).

Age Estimate

The previous battery you listed (750450-001) was manufactured in December 2014.

This one (serial 6WQXKONWYGJ5EI) uses the same 6WQX serial family and very similar formatting, so it is almost certainly from the same 2014–2015 production period (or very close). These batteries are now 11+ years old.

HPE rates the service life of these Li-ion Smart Storage batteries at roughly 3–5 years under normal conditions. At this age, capacity is typically degraded even if it still reports “OK” in the server.

Status Recommendation

* Check the battery health immediately in HPE iLO (Integrated Lights-Out) or Smart Storage Administrator (SSA / iLO REST). Look for:

* Charge level

* Battery status (OK / Low / Failed / Replace)

* Any FBWC-related warnings

* Cache mode (Write-Back vs Write-Through)

If it shows any warning or is still in use after 11 years, replace it to avoid sudden cache protection loss, performance degradation, or data-risk scenarios during power events.