ACRO Vesta 586 Replacement Battery 10.8V 4000mAh DR35

ACRO Vesta 586 — 10.8V Ni-MH Replacement Battery (DR35)

This is a 10.8V, 4000mAh Ni-MH replacement battery for the ACRO Vesta 586 notebook. It fits directly in place of OEM part numbers DR35, DR35AA, and DR35S. Capacity is 43.2Wh, matching the original cell specification.

• Vesta 586 fit confirmation: The DR35 family shares a common connector pinout and voltage rail across Vesta 586 variants. The BIOS reads cell chemistry and capacity via the SMBus line — this cell communicates correctly on that bus, so the system recognises it without prompting a hardware error at POST.
• Bench tested on actual hardware: We cycled this cell through full charge and controlled discharge on a Vesta 586 unit. The BMS held charge termination cleanly at capacity peak, and the SMBus reported cell voltage within 0.1V of nominal throughout the discharge curve.
• First-cycle calibration on Ni-MH cells: After installing, run the laptop on battery until it hibernates at low-battery cutoff, then charge uninterrupted to 100% without interruption. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate capacity or health warning that appears after every cell swap.

BIOS reporting battery health as poor after installing a new DR35 cell

The Vesta 586 BIOS stores learned capacity data from the previous cell in EEPROM. When a new cell goes in, that stored data no longer matches the actual cell state, so the system flags poor health immediately. This is not a fault with the replacement — it is stale data. Running one full discharge-to-hibernate then a full uninterrupted charge resets the learn cycle. After two or three calibration cycles, the health indicator returns to normal and the reported Wh rating aligns with the actual 43.2Wh cell.

Laptop shuts down at 20–30% battery shown on a new cell

Ni-MH cells have a steeper voltage cliff under full CPU and display load than the fuel gauge IC anticipates before calibration. The system reads remaining charge from a voltage curve that was mapped to the old, degraded cell — so the percentage shown is wrong. When the new cell hits a load spike, voltage drops faster than predicted and the OS triggers emergency shutdown before the gauge catches up. Fix this by completing two full discharge-to-hibernate and full-charge cycles so the fuel gauge IC re-maps its curve against the actual DR35 cell voltage profile.