IEEE 1625:2008 pdf free download – IEEE Standard for Rechargeable Batteries for Multi-Cell Mobile Computing Devices
1.1 Scope
This standard establishes criteria for design analysis for qualification，quality，and reliability ofrechargeable battery systems for multi-cell mobile computing devices.It also provides methods forquantifying the operational performance of these batteries and their associated management and controlsystems including considerations for end-user notification. This standard covers rechargeable batterysystems for mobile computing. The battery technologies covered are limited to Li-ion and Li-ion polymer,but future versions of this standard may include technologies that are not in general use at present. Alsoincluded are: battery pack electrical and mechanical construction; system, pack, and cell level charge anddischarge controls; and battery status communications. The following are addressed: qualification process;manufacturing process control; energy capacity and demand management;levels of management andcontrol in the battery systems;current and planned lithium-based battery chemistries，packagingtechnologies, and considerations for end-user notification.
4.1 General
This clause sets forth provisions for conducting design analyses for cell, pack,host devices，and poweradapters and an overal system-level design analysis of the combination of thesc,including the end user.The design analyses shall be conducted to minimize hazards (as defined in Annex F) from occurring as aresult of one or two independent faults while in intended use, depending on scenario. The analysis shallconsider two independent faults for charge and one fault for discharge and storage situations. The designanalysis shall also be conducted to minimize hazards from occurring due to reasonably foreseeable misuse.Table 1 lists several different design analysis techniques that can be used.Conditions beyond reasonablyforesecable misuse are outside the scope of this standard. While design analyses should be thorough, it isnot practical to address every conceivable scenario. Such an approach would prove onerous and unrealistic.Furthermore,cell design and manufacturing quality is fundamental to system design safety, as cell faultsthat create a hazard cannot be mitigated by external subsystems. To minimize hazards, there is no substitutefor the use of high-quality cells manufactured in accordance with Clause 5.
5.1 General
Cell manufacturers/suppliers shall provide cell specifications，incorporating a definition of an Operatingregion. See Annex E for a templatc for a Cell specification sheet with minimum content. Ceilmanufacturers shall define the Operating region of their Li-ion batteries to the pack and systemmanufacturers. The following describes limits for the Li-ion battery system design; since each chemistry isdifferent, they require varying charging profiles, per specifications. For an example, see Figure 2 for anexplanation of Operating region (charging) in which the upper limit for the charging voltage is 4.250 V forcommon lithium cobalt oxide/graphite in the Operating region for the following temperatures: 10 °C to45 ℃.
This clause includes the precautions and considerations required for design, manufacturing, and testing ofrechargeable Li-ion and Li-ion polymer cells,over their product lifetime, to minimize latent problems.Design parameters shall be of the format: limit + tolerancec 1/- tolerance 2, or max limit and min limit, asdefined by the cell manufacturer/supplier. For example, if a cell manufacturer/supplier specifies that thevoltage of a cell is 4.250 V +0.000 V/-0.100 v, the circuit design shall ensure that this maximum is notexceeded. If the measuring device has a tolerance of±0.005 V, then the circuit shall be designed to operateto 4.245V± 0.005 V, in order not to exceed the maximum.The measurement tolerance should have a4-sigma confidence.
Figure 3 depicts typical cell construction for cylindrical [part (a) of Figure 3], prismatic [part (b) of Figure 3],pouch prismatic [part (c) of Figure 3], and stacked pouch polymer cells [part (d) of Figure 3].