Method and system for battery protection

Abstract

A system and method for battery protection. In some aspects, a method of conducting an operation including a battery pack, includes the acts of monitoring a first battery pack condition at a first monitoring rate, determining when a second battery pack condition reaches a threshold, after the second battery pack condition reaches the threshold, monitoring the first battery pack condition at a second monitoring rate, the second monitoring rate being different than the first monitoring rate. In some aspects, a method of conducting an operation including a battery, the battery including a cell having a voltage, power being transferable between the cell and the electrical device, a controller operable to control a function of the battery pack, the controller being operable with a voltage at least one of equal to and greater than an operating voltage threshold, the cell being operable to selectively supply voltage to the controller, includes the act of enabling the controller to operate when the voltage supplied by the cell is below the operating voltage threshold.

Description

FIELD OF THE INVENTION The present invention generally relates to a method and system for battery protection and, more particularly, to a method and system for power tool battery protection. BACKGROUND OF THE INVENTION Cordless power tools are typically powered by portable battery packs. These battery packs range in battery chemistry and nominal voltage and can be used to power numerous tools and electrical devices. Typically, the battery chemistry of a power tool battery is either Nickel-cadmium (“NiCd”), Nickel-Metal Hydride (“NiMH”) or lead-acid. Such chemistries are known to be robust and durable. SUMMARY OF THE INVENTION Some battery chemistries (such as, for example, Lithium (“Li”), Lithium-ion (“Li-ion”) and other Li-based chemistries) require precise charging schemes and charging operations with controlled discharge. Insufficient charging schemes and uncontrolled discharging schemes may produce excessive heat build-up, excessive overcharged conditions and / or excessive ove...

AI Technical Summary

Benefits of technology

Some battery chemistries (such as, for example, Lithium (“Li”), Lithium-ion (“Li-ion”) and other Li-based chemistries) require precise charging schemes and charging operations with controlled discharge. Insufficient charging schemes and uncontrolled discharging schemes may produce excessive heat build-up, excessive overcharged conditions and / or excessive overdischarged conditions. These conditions and build-ups can cause irreversible damage to the batteries and can severely impact the battery's capacity. Various factors, such as, for example, excessive heat, can cause one or more cells within the battery pack to become imbalanced, that is, to have a present state of charge that is substantially lower than the remaining cells in the pack. Imbalanced cells can severely impact the performance of the battery pack (e.g., run-time and / or voltage output) and can shorten the life of the battery pack.

Problems solved by technology

Insufficient charging schemes and uncontrolled discharging schemes may produce excessive heat build-up, excessive overcharged conditions and / or excessive overdischarged conditions.

These conditions and build-ups can cause irreversible damage to the batteries and can severely impact the battery's capacity.

Various factors, such as, for example, excessive heat, can cause one or more cells within the battery pack to become imbalanced, that is, to have a present state of charge that is substantially lower than the remaining cells in the pack.

Imbalanced cells can severely impact the performance of the battery pack (e.g., run-time and / or voltage output) and can shorten the life of the battery pack.

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