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→Comparison between the batteries
In this method, battery is charged with a constant current until voltage reaches the end-of-charge(EOC) voltage. Thereafter, charger switches to a constant voltage charging, where the charging current falls with time. The battery is said to be charged when the charging current drops to a predetermined limit. This is the preferred mode for charging Li-ion batteries.
[[File:BatCharge.png|frame|center|Constant Current Constant Voltage Mode of Charging. Image reproduced from [http://www.ti.com/lit/ds/symlink/bq2057.pdf here]]]
== Battery Discharging ==
=== Comparison between the batteries ===
{| class="wikitable"
|+ Comparison between batteries <ref name ="ieee"/>
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|'''System'''
A PTC (Positive Temperature Coefficient) switch can also be used to prevent short-circuiting by inhibiting high currents. As temperature increases above a limit, material resistance faces a large increase and being reversible they cycle back to conductive state when we have normal condition again.
CIDs (Current Interrupter Devices) can prevent further charging of a battery until internal pressure(of battery) is alleviated. These devices prevent venting of hazardous electrolytes and bursting due to buildup of high pressures.<ref name = "nasa2">https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150020899.pdf </ref> However, both PTCs and CIDs may fail when exposed to high voltages due to other failures. The use of bypass diodes is recommended to prevent these failures.<br \>
The surfaces of battery terminals that extend inside the battery case need to be insulated with potting materials to prevent unintentional contact with other conductors inside the case and also to prevent bridging by electrolyte leaks. Wires inside the battery case should be insulated, restrained from contact with cell terminals, protected against chafing and physically constrained from movement due to vibration or bumping.<ref name = "nasa"/>
Certification of the crimp is critical for ensuring that individual cells will not leak after launching.<ref name = "nasa2"/> Cell terminals need to be protected from contact with other conductive surfaces. <br \>
If you are done reading this page, you can go back to [[Electrical Subsystem]]
==References==