Battery charger with charge indicator

• US 7,843,167 B2
• Filed: 01/22/2007
• Issued: 11/30/2010
• Est. Priority Date: 01/22/2007
• Status: Active Grant

• Current Assignee: Snap-On Incorporated
• Original Assignee: Snap-On Incorporated
• Inventors: Rayner, Martin M., DeRome, Raymond D.
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): DIAO, M BAYE
• Application Number:
  US11/625,719
• Publication Number:
  US 20080174269A1
• Time in Patent Office: 1,408 Days
• Field of Search: 320/107, 320/110, 320/111, 320/112, 320/114, 320/162, 320/106, 320/113, 320/115, 320/150, 320/152, 307/150, 324/450, 429/62, 429/92, 429/123, 429/155
• US Class Current: 320/112
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition

Abstract

A battery charger having an integrated battery charge indicator that is readily visible when a battery pack is connected for charging. The battery charge indicator is on a visible outer surface of the housing of the battery charger to indicate a state of charge of the battery pack. The indicator may include a series of light emitting diodes with one LED that is illuminated when the battery pack is charging and will flash if something is wrong with the battery pack. The housing can preferably accommodate more than one configuration of battery packs with the indicator being visible when various battery packs are attached for recharging.

Claims

1. A battery pack charger comprising:

a housing including a shoe for receiving a slide on battery pack configurations and a cavity for receiving blade battery pack configurations;

a voltage divider network configured to be coupled with a battery pack engaged with at least one of the shoe and cavity;

a controller coupled with the voltage divider network and operable to detect multiple voltage levels in the voltage divider network,

wherein the controller is operable to detect a voltage level and voltage capacity of the battery pack based on the voltage divider network;

a charging circuit configured to provide a charging current to a battery pack, wherein the charging circuit is coupled with the controller;

a visual display coupled with the controller, the visual display indicating multiple levels of the state of charge of a battery pack attached thereto;

wherein the controller controls a charging current with which the charging circuit charges the battery pack; and

wherein the controller drives the visual display with a signal indicative of one of multiple levels as a percentage level of battery charge level.

2. The battery pack charger of claim 1,

wherein the controller is operable to store correlation data indicative of a battery charge level correlating to voltage levels detected in the voltage divider network and

wherein the controller is operable to determine a charge level of the battery pack by looking up a battery charge level in the correlation data corresponding to voltage levels detected in the voltage divider network.

3. The battery pack charger of claim 1,

wherein the controller is configured to determine a type of battery pack by detecting a voltage drop across terminals of the battery pack.

4. The battery pack charger of claim 3,

wherein the controller adjusts the charging current with which the charging circuit charges the battery pack based on the detected type of battery pack.

5. The battery pack charger of claim 4, further comprising

the battery pack including a positive terminal,

a negative terminal and

a battery pack detection terminal,

wherein the positive terminal and the negative terminal are configured to be coupled with the charging circuit,

wherein the battery pack detection terminal is configured to be coupled with the controller,

wherein the controller determines the type of battery pack based on a voltage level on the battery pack detection terminal.

6. The battery pack charger of claim 5, wherein the battery pack includes a battery portion coupled between the positive terminal and the negative terminal and a NTC resistor coupled between the battery pack detection terminal and the negative terminal.

7. The battery pack charger of claim 6, further comprising at least one diode coupled in parallel with the NTC resistor.