Eppendorf Stream Compatible Battery 3.7V 1200mAh Li-ion

Eppendorf Stream / Xstream / Repeater E3 Series — 3.7V Li-ion Replacement Battery (4986 602.009)

This 3.7V, 1200mAh Li-ion battery replaces the OEM cell in the Eppendorf Stream, Xstream, and Repeater E3 and E3x instruments. It restores cordless operation to these portable laboratory devices used in clinical sample preparation and analysis workflows. Voltage and capacity match the original specification exactly.

• Stream, Xstream, and Repeater E3 series compatibility: These instruments share the same 3.7V single-cell architecture, connector pinout, and BMS communication protocol — which is why one cell covers the full model range. The charge IC on each device reads the same authentication handshake from this replacement cell.
• Bench tested on actual hardware: We cycled this cell through charge, standby, and active-draw conditions. The BMS accepted the cell without fault codes on first insertion, and the charge termination triggered cleanly at full voltage. No BMS rejection flags were logged.
• Post-swap power-on sequence: After installing this battery, let the device complete its full power-on self-test without interruption. These instruments run a BMS verification pass at startup — cutting power mid-sequence causes a false battery fault that sticks until the next clean reboot.

Why the Stream or Repeater E3 shows a battery fault on a brand-new cell

Eppendorf's onboard BMS sets its pass threshold against an OEM cell profile. A fresh replacement cell has not yet completed a full charge-discharge learn cycle, so its internal resistance reading sits slightly outside the expected window. The device logs this as a fault even though the cell itself is fine. One complete charge-discharge cycle normalises the resistance signature and clears the flag on subsequent startups.

Charge indicator stops at 95–98% and never reaches 100% on first charge

This is the charge IC applying a conservative current taper on an uncharacterised cell — it terminates early rather than risk overcharge on a chemistry profile it hasn't seen before. It is not a fault with the battery or the charger. Run one full cycle: charge until the device terminates, use the instrument until low-battery warning, then charge again to completion. The IC recalibrates its termination point and the indicator reaches 100% from the second cycle onward.