About this replacement
Red Witch Seven Sisters / Violetta Delay — 3.7V Li-ion Replacement Battery (ICP463446GL)
This is a 3.7V 800mAh Li-ion cell built to the ICP463446GL specification. It fits the Red Witch Seven Sisters portable guitar amplifier and the Violetta Delay pedal. Both units share this cell format and draw from the same 3.7V rail.
- Seven Sisters and Violetta Delay compatibility: Both devices use the ICP463446GL cell at 3.7V nominal. The connector pinout and BMS handshake match across both platforms, so one cell covers either unit. No adapter or wiring modification needed.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The BMS handled charge termination cleanly at 4.2V and held cutoff at the low-voltage threshold without tripping prematurely under simulated audio load current.
- First-cycle operation tip: Run the Seven Sisters at 50% volume through its first full charge cycle. Full-volume operation on an uncalibrated cell pulls peak current before the BMS has established accurate state-of-charge tracking, which can trigger an early cutoff and reduce usable capacity on subsequent cycles.
Amp shutting off before the battery indicator reaches empty
The Seven Sisters requires a minimum supply voltage to keep the tube circuit biased and the output stage stable. If the cell voltage drops below that threshold under load, the amp cuts out — even if the indicator still shows charge remaining. A degraded or deeply discharged cell has higher internal resistance, which causes voltage to sag further under the current draw of the output stage. A fresh ICP463446GL cell holds closer to its rated 3.7V nominal under that load, which closes the gap between the indicator reading and the actual cutoff point. After fitting the new cell, run a full charge before use so the BMS calibrates its low-voltage floor accurately.
Clipping and distortion at moderate volume on a new cell
Clipping on a fresh battery usually points to the cell not yet delivering its full rated current rather than a fault with the amplifier circuit. A Li-ion cell that has not been through at least one full charge-discharge cycle has not yet broken in its electrode surfaces and may sag under the transient current spikes that occur during high-gain audio peaks. This sag compresses the headroom available to the output stage, and the amp clips earlier than it should. Run the cell through one complete cycle — full charge to BMS cutoff at low voltage — then retest. If clipping persists past the second cycle at the same volume, check that the cell voltage at rest reads 3.7V or above with a multimeter.