About this replacement
Samsung SGH-i607 / SGH-i600 BlackJack — 3.7V Li-ion Replacement Battery (AB653450CABSTD)
This is a 3.7V Li-ion cell rated at 1200mAh (4.44Wh), built to the same electrical spec as the original AB653450CABSTD. It fits the Samsung SGH-i607 and SGH-i600 BlackJack series smartphones. The physical dimensions are 51.43 × 37.11 × 6.62mm — check these against your battery bay before ordering.
- SGH-i607 / SGH-i600 / BlackJack compatibility: These models share the same battery bay dimensions, 3.7V nominal voltage rail, and connector pinout. All part numbers listed — AB653450CAB, AB653450CE, AB663450CEC, AB663450CA, AB663450CU — cross-reference to the same cell spec and fit the same chassis variants.
- Bench tested on actual hardware: We cycled this cell through a full discharge-charge sequence and verified BMS handshake at the connector. The protection circuit tripped correctly at the low-voltage cutoff threshold and recovered normally on reconnection to a 5V charge source.
- Fuel gauge recalibration on first install: On first use after installation, disable any fast-charging accessory for one complete discharge-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging is applied to an uncalibrated cell.
Why the SGH-i607 reports wrong battery percentage after a cell swap
The SGH-i607 uses a fuel gauge IC that builds its charge estimate from the previous cell's discharge curve stored in memory. When you swap in a new cell, that stored curve no longer matches the actual cell chemistry. The gauge reads voltage and translates it to a percentage using old reference data, so the number on screen drifts from reality. One full discharge down to auto-shutoff followed by a full uninterrupted charge resets the reference and brings the percentage back into alignment.
Sudden shutdown at 20–30% on the replacement cell
This happens when the modem or display pulls a high current burst and the cell voltage drops sharply below the BMS cutoff threshold — even though the gauge still shows charge remaining. The fuel gauge IC has not yet learned the new cell's voltage sag curve under load, so it doesn't anticipate the drop. The BMS sees the instantaneous voltage dip as a fault and cuts power before the gauge registers zero. Run one full discharge-to-shutoff cycle, then charge to 100% without interruption — after that single cycle the gauge IC recalibrates and the shutoffs stop.