Apple iPod Video 5th Gen TF424090 Replacement Battery 3.8V

Apple iPod Video 5th / 5.5 Gen — 3.8V Li-Polymer Replacement Battery (TF424090)

This 3.8V, 3000mAh Li-Polymer cell replaces the original battery in the Apple iPod Video 5th and 5.5 Gen 60GB and 80GB iFlash. It fits the slim chassis without modification and connects to the same flex-ribbon connector used across the iPod Video line. Capacity is rated at 11.4Wh — above the stock cell Apple shipped in most 5th Gen units.

• 60GB and 80GB iFlash coverage: Both variants share the same battery bay dimensions and connector pinout. The 80GB iFlash model was a common upgrade target, and this cell fits the modified chassis without repositioning.
• Bench tested on actual hardware: We ran this cell on a 5.5 Gen board. The BMS initialised cleanly on first connection, accepted charge current within seconds, and the fuel gauge updated without a recalibration cycle.
• First-charge behaviour after cell swap: After installing, charge fully before using the device. iPod Video units can enter deep-discharge protection if the new cell voltage sits below the controller's wake threshold — a slow trickle through the dock connector clears that state before normal charge current is accepted.

Battery percentage jumping after a cell swap on iPod Video

The iPod Video uses a voltage-threshold fuel gauge — it reads cell voltage and maps it to a percentage using a fixed curve calibrated to the original battery's discharge profile. After a cell swap, that curve no longer matches the new cell's actual voltage behaviour, so percentage readings jump or stall at unexpected points. The gauge corrects itself after one or two full charge-and-discharge cycles. Run the battery from 100% down to automatic shutdown, then charge fully — the curve recalibrates from those endpoint voltages.

Playback cutting out before the battery reads empty

The audio amplifier in the iPod Video draws a short current spike during playback that can sag cell voltage below the BMS cutoff threshold — even when the indicator still shows a partial charge. This happens more often at the tail end of discharge, where internal cell resistance rises and voltage sag widens. The fix is to avoid running the device down to the single-digit percentage range. Charge when the indicator reaches 15% and voltage sag-related shutoffs stop occurring.