About this replacement
Shark V3700UK Series — 3.7V Li-ion Replacement Battery (XBAT3700 Type 1)
This is a 3.7V 2600mAh Li-ion replacement battery for the Shark Cordless Rechargeable Hard Floor Sweeper V3700UK, V3700 Type 1, and V3700UK Type 1. It slots into the original battery compartment and works with the existing charging dock. Capacity is rated at 9.62Wh — matching the original cell specification.
- V3700 series fit: The V3700, V3700UK, and V3700 Type 1 all share the same battery bay dimensions, connector pinout, and BMS handshake requirements. One battery covers all three variants without modification.
- Bench tested on actual hardware: We ran this cell through the Shark charging dock and confirmed the BMS accepted the charge cycle without fault codes. The protection circuit responded correctly to both low-voltage cutoff and over-discharge recovery.
- Dock charging habit for the V3700: Do not leave the V3700 sitting on the dock permanently. Continuous trickle charging accelerates lithium-ion cell degradation faster than charge-when-depleted cycles. Charge to full, then remove from the dock until the next use.
Suction dropping before the battery indicator shows low on the V3700UK
This happens when the motor draws more current than the cell can sustain at its present state of charge. A partially blocked filter forces the motor to work harder, pulling current beyond the cell's rated discharge rate. The BMS then reduces output voltage to protect the cell — which registers as a loss of suction, not a low-battery warning. Clear the filter first, then check that the cell voltage under load holds above 3.2V.
V3700 motor cutting out mid-use then recovering after a few seconds
This is a BMS overcurrent trip, not a failing cell. When suction is restricted — by a blocked filter or a debris jam at the intake — current spikes past the protection circuit threshold and the BMS shuts the motor off. It resets automatically once current drops, which is why the sweeper comes back on after a short pause. Fix the restriction first. If cutouts continue on a clear filter, check that the battery terminals are seating fully and that resting cell voltage is at or above 3.6V before each use.