Vision LED DayLite 7.4V Replacement Battery DVI-LEDS 3350mAh

Vision LED DayLite / LED DayLite HDi — 7.4V Li-ion Replacement Battery (DVI-LEDS / OM0046)

This is a 7.4V, 3350mAh Li-ion replacement battery for the Vision LED DayLite and LED DayLite HDi portable medical examination lights. It slots in where the original pack sits and restores full LED illumination output. Voltage and capacity match the OEM spec: 7.4V, 3350mAh (24.79Wh).

• LED DayLite and HDi compatibility: Both the standard DayLite and the HDi share the same 7.4V Li-ion cell format, connector pinout, and BMS handshake protocol — that's why one pack covers both. The HDi variant draws slightly more current at peak brightness, but sits within the same voltage rail.
• Bench tested on actual hardware: We cycled this pack under a simulated clinical load profile. The BMS held voltage within the expected window, balanced the cells correctly, and tripped protection at the right cutoff threshold — no premature shutdowns during the test run.
• Post-swap self-test protocol: After installation, let the device complete its full power-on self-test without interruption. The DayLite's BMS runs a verification sequence at startup — cutting power mid-cycle flags a false battery fault that won't clear until the next clean reboot.

Why the LED DayLite reports a battery fault after a confirmed full charge

The DayLite's charge IC applies conservative thresholds calibrated against OEM cell chemistry. A new replacement cell hasn't completed a full charge-discharge learn cycle, so the BMS may log a fault even when the pack reads full. This isn't a defective battery — it's the device's protection logic treating an uncalibrated cell with caution. Run one complete charge-to-discharge cycle before using the light in a clinical setting, and the BMS will register the new cell's actual capacity baseline.

Device not powering on after the battery sat in storage

Li-ion cells self-discharge during storage. If the pack voltage drops below approximately 2.5V per cell (5.0V at pack level), the BMS engages deep-discharge lockout and blocks normal startup. The device won't power on — it may show nothing at all. Place the pack on charge immediately and leave it for a full charge cycle without interrupting. Most BMS circuits recover cells at this level; if the charge indicator doesn't activate within 30 minutes, the cell voltage has likely dropped below the recovery floor.