Battery Architecture; Bms (Battery Management System) - Toro 88620 Service Manual

Battery Architecture

Cell/Power Pack
Battery Architecture
Battery Makeup

BMS (Battery Management System)

Features Managed by BMS
60v Battery Service Manual
3439-480 Rev A
See Operator's Manual for additional information.
Inside the battery pack are the cell/power pack and BMS (Battery Management
System) combined to ensure the battery in the tool works the way it's supposed
to.
The first component of the battery pack is the cell pack. Cell packs come in a
variety of formats, different shapes and sizes, for different applications. Many
factors impact what type of battery format is used in any particular product as
each format has advantages and disadvantages. Toro designs the batteries
within the context of how the battery will be used in the products and consider
everything from manufacturing costs to heat dissipation and efficient use of
space to weight concerns.
Some of the advantages of using cylindrical cell packs is that they have good
mechanical stability. Cylindrical cell packs typically have longer calendar life and
cycling ability and higher energy density.
While the battery is discharging and providing an electrical current, the anode
(-) releases lithium-ions to the cathode (+), generating a flow of electrons from
one side to the other. When plugging in the device, the lithium-ions are released
by the cathode (-) and received by the anode (+).
A battery is made up of an anode, cathode, separator, electrolyte and 2 current
collectors (positive and negative).
•
The anode and cathode store the lithium.
•
The anode releases the lithium-ions when the battery is discharging. The
cathode releases lithium-ions when the battery is charging.
•
The electrolyte carries positively charged lithium-ions from the anode to the
cathode and vice versa through the separator.
•
The movement of the lithium-ions creates free electrons in the anode which
creates a charge at the positive current collector.
•
The electrical current then flows from the positive current collector through a
device being powered to the negative current collector.
•
The separator blocks the flow of electrons inside the battery.
The second component of the battery pack is the BMS. The BMS serves as the
controller of the battery pack and communicates with the control of the tool to
ensure the tool and battery are working optimally.
Features managed by the BMS include the state-of-charge indicator lights,
monitoring of voltage and temperature, and communication between the battery,
the charger, and the tool. The BMS determines if the conditions are right to
charge or discharge and it authenticates the correct battery for the tool.
Page 4–5 Theory of Operation: Service and Repairs