Skil 2536 AC Cordless Screwdriver Replacement Battery 3.7V

My Skil 2536 AC screwdriver feels weaker than the old battery even though the charge light went green — is something wrong?

A green charge light confirms the battery reached termination voltage, but it doesn't confirm full capacity was delivered — especially on a first cycle with a new Li-ion cell. At 3.6–3.7V and 1.3Ah original spec, this tool runs a narrow power band, and a new higher-capacity cell like this one can take two or three full discharge-recharge cycles before the internal chemistry settles and output feels consistent. Run it until the screwdriver noticeably slows, charge it fully, and repeat. If torque still feels soft after three cycles, check the contact pins on the battery compartment for oxidation — a dirty contact at this voltage drops performance faster than on higher-voltage packs.

The Twist function on my 2536 AC stopped working after I swapped the battery — the motor runs but the head won't pivot anymore.

The Twist mechanism is mechanical, not electrical, so the battery swap itself didn't cause this — but jarring the tool during the swap or reassembly can dislodge the pivot collar if it was already worn. Check that the battery is fully seated and latched, because a partially connected pack on a 3.7V tool can cause erratic torque that mimics a mechanical fault. With the tool powered off, try manually rotating the head through its range — if it resists or catches in one spot, the fault is in the collar joint, not the battery. If the head pivots freely unpowered but the motor won't drive it under load, measure the battery terminal voltage under load with a multimeter; it should hold above 3.4V.

The LED light on my 2536 AC comes on but the motor doesn't turn — new battery fully charged.

The LED draws almost nothing, so it lighting up confirms basic circuit continuity — but the motor circuit on small 3.6V screwdrivers has a separate protection path that can trip if the pack voltage looked out of range during initialization. This sometimes happens when a new Li-ion cell with a higher resting voltage (around 4.1–4.2V fresh off charge) confuses the tool's low-side cutoff logic, which was calibrated for the original 1.3Ah cell. Remove the battery, wait 60 seconds, reinstall it firmly, and trigger the motor immediately without pre-pressing the Twist button. If it still won't spin, check that both battery terminals are making clean contact — at this cell size, even a 0.1mm gap on a spring contact can break the motor circuit entirely.