Failure avoidance for battery packs having overcharge protection circuits
AssigneeBlack & Decker Inc.
InventorsNathan Osborne, Nicholas J. Garibaldi
Life of this patent
Estimating the term…
Abstract
A battery pack is provided for use with a power tool. The battery pack includes a housing and a plurality of battery cells connected in series within the housing, such that an inter-cell node is defined between each pair of adjacent battery cells. A plurality of terminals is at least partially exposed outside of the housing for coupling the battery cells to at least one of a power tool or a battery charger. The plurality of terminals include a positive terminal, a negative terminal and one or more inter-cell terminals, where at least one of the inter-cell terminals is electrically coupled via a positive temperature coefficient thermistor to one of the inter-cell nodes.
Claims14
A battery pack for use with a power tool, comprising:
- a housing;
- a plurality of battery cells connected in series within the housing and having an inter-cell node defined between each pair of adjacent battery cells in the plurality of battery cells;
- a plurality of terminals at least partially exposed to an outside of the housing and configured to electrically couple the battery cells to at least one of the power tool or a battery charger, where the plurality of terminals include a positive terminal, a negative terminal and one or more inter-cell terminals, where at least one of the inter-cell terminals is electrically coupled via a positive temperature coefficient thermistor to one of the inter-cell nodes;
- and
- a protection circuit configured to measure voltage across each of the battery cells during a charging operation and operates to discontinue the charging operation when voltage across a given cell exceeds a threshold.
A battery pack for use with a power tool, comprising:
- a housing;
- a plurality of battery cells connected in series within the housing, such that an inter-cell node is defined between each pair of adjacent battery cells in the plurality of battery cells;
- a plurality of terminals configured to electrically couple the battery cells to the power tool and at least partially exposed to an outside of the housing, where the plurality of terminals include a positive terminal, a negative terminal and one or more inter-cell terminals;
- and
- a protection circuit configured in the housing to measure voltage across each of the battery cells during a charging operation and operates to discontinue the charging operation when the voltage across a given cell exceeds a threshold, wherein each inter-cell terminal is electrically connected individually by a circuit path to a corresponding one of the inter-cell nodes and each circuit path is electrically connected individually to the protection circuit, such that a thermistor is disposed in each circuit path between the inter-cell terminal and the inter-cell node.
Dependencies are inferred from the claim text.