Safety device for managing batteries
View Patent ↗A safety device for lithium ion cells or groups of lithium ion cells connected in parallel and in series by providing a continuously balanced state of charge while in a discharge phase, a charge phase, a quiescent phase, a storage phase, or combinations of these phases.
1. A safety device for balancing a plurality of cells or groups of cells connected in series, or in parallel and in series, comprising:
a. a controller assembly comprising an analog controller and a digital controller with the plurality of cells or groups of cells connected in series;
b. a disconnect circuit, comprising a charge switch and a discharge switch connected in series, engaging the controller assembly and the plurality of cells or groups of cells connected in series;
c. a pack sensing circuit comprising a member selected from the group consisting of a means for measuring temperature, a means for measuring current, and a means for measuring cell voltages; and wherein the pack sensing circuit connects to the controller assembly and the plurality of cells or groups of cells connected in series;
d. a balancing circuit comprising a shunt resistor connected to a by-pass switch, wherein the balancing circuit connects between the plurality of cells or groups of cells connected in series and engages the controller assembly; and
e. computer instructions for instructing the controller assembly within the safety device to control the disconnect circuit and the balancing circuit; and wherein the plurality of cells or groups of cells connected in series are balanced when operating in a charging phase, a discharging phase, a quiescent phase, and a storage phase.
2. The safety device of claim 1 , wherein the digital controller further comprises at least one configuration table.
3. The safety device of claim 1 , further comprising a reverse voltage protection diode for preventing excessive voltage from developing across the controller assembly.
4. The safety device of claim 1 , further comprising a bypass diode for balancing a plurality of cells or groups of cells by discharging the plurality of cells or groups of cells until a balance phase is achieved.
5. The safety device of claim 1 , wherein the by-pass switch comprises a member selected from the group consisting of a semiconductor switch, a variable resistor, a mini-micro switch or combinations thereof.
6. The safety device of claim 1 , wherein the means for measuring temperature is external to the controller assembly.
7. The safety device of claim 1 , wherein the means for measuring current is external to the controller assembly.
8. The safety device of claim 1 , wherein the means for measuring cell voltages between cells, between groups of cells or combinations thereof is internal to the analog controller.
9. The safety device of claim 1 , wherein the digital controller comprises an analog I/O port, a processor, memory with processing logic and computer instructions for directing the processor.
10. The safety device of claim 9 , further comprising data storage in communication with the processor for storing the computer instructions.
11. The safety device of claim 1 , wherein the computer instructions for controlling the disconnect circuit direct the processor to connect the plurality of cells or groups of cells connected in series to a charger to connect the plurality of cells or groups of cells connected in series to an application.
12. The safety device of claim 1 , wherein the plurality of cells is connected together in series forming groups of cells connected in series.
13. The safety device of claim 12 , wherein at least two groups of parallel connected cells are connected in series together.
14. The safety device of claim 1 , further comprising a voltage regulator communicating with the controller assembly.
15. The safety device of claim 14 , wherein the voltage regulator is a DC programmable voltage regulator.
16. The safety device of claim 1 , wherein the plurality of cells or groups of cells are lithium ion cells.