background preloader

Charging Lithium-Ion Batteries – Battery University

Charging Lithium-Ion Batteries – Battery University
Find out how to prolong battery life by using correct charge methods. Charging and discharging batteries is a chemical reaction, but Li-ion is claimed to be the exception. Battery scientists talk about energies flowing in and out of the battery as part of ion movement between anode and cathode. This claim carries merits but if the scientists were totally right, then the battery would live forever. They blame capacity fade on ions getting trapped, but as with all battery systems, internal corrosion and other degenerative effects also known as parasitic reactions on the electrolyte and electrodes till play a role. The Li ion charger is a voltage-limiting device that has similarities to the lead acid system. Charging Cobalt-blended Li-ion Li-ion with the traditional cathode materials of cobalt, nickel, manganese and aluminum typically charge to 4.20V/cell. Figure 1 shows the voltage and current signature as lithium-ion passes through the stages for constant current and topping charge. Related:  batteryenergy ,nutrition, battery management of all thisCharging Batteries

batteries - Use a lithium ion battery from a laptop, for a small project? Measuring State-of-charge - Battery University Comments On September 21, 2011 at 12:51pm Joe Accetta wrote: There is yet another and quite accurate means of measuring SOC in open port lead acid batterieis through the use of refractometry. The index of refraction of the electrolyte is directlly proportional to the SG. JSA Photonics has developed an in-cell immersion refractometer that yields accurate 24/7 SOC information along with cell temperature for monitoroing and temp correction and in some instances electrolyte level. On October 13, 2011 at 4:02am Josep wrote: I’m investigating about, and I read that the most common, easy, and accurate way of measuring OSC is Ampere Hour Counting. On November 29, 2011 at 7:15am Qaisar Azeemi wrote: Its really nice information about SOC is given here. On January 20, 2012 at 5:05am kishore kumar wrote: Its good to know about soc. On January 25, 2012 at 1:34pm Diego wrote: Kumar wrote: Regards!

Charging Batteries at High and Low Temperatures Learn how to extend battery life by moderating ambient temperatures. Rechargeable batteries operate in a wide temperature range but this does not give license to charge them at extreme temperatures. Extreme cold and high heat reduce charge acceptance, and the battery must be brought into moderate temperature conditions before charging. Older battery technologies, such as lead acid and NiCd, have higher charging tolerances than newer systems and can be charged below freezing at a reduced 0.1C rate. This is not possible with most NiMH and lithium-ion systems. Table 1 summarizes the permissible charge and discharge temperatures of common lead acid, NiCd, NiMH and Li ion. Table 1: Permissible temperature limits for various batteries. Low-temperature Charge Fast charging of most batteries is limited to a temperature of 5 to 45°C (41 to 113°F); for best results consider narrowing the temperature bandwidth to between 10°C and 30°C (50°F and 86°F). Do not freeze a lead acid battery.

How to Repair a Laptop Battery – Battery University Most laptop batteries are smart. This means that the pack consists of two parts: the chemical cells and the digital circuit. If the cells are weak, cell replacement makes economic sense. A laptop battery may have only one weak cell, and the success rate of replacing the affected cell depends on the matching with the others. The typical SMBus battery has five or more battery connections consisting of positive and negative battery terminals, thermistor, clock and data. Some batteries are equipped with a solid-state switch that is normally in the “off” position and no voltage is present on the battery terminals; connecting the switch terminal to ground often turns the battery on. How can you find the correct terminals? Establishing the connection to the battery terminals should now enable charging. Some battery manufacturers add an end-of-battery-life switch that turns the battery off when reaching a certain age or cycle count.

电池能源管理电路bq2040工作原理及其应用,电池能源管理,SM总线接口,内存映射配置,bq2040-中电网 1 概况 笔记本电池内有电池控制板。它控制电池的充放电,还要承担电池状况的分析记录,并在电池温度过高或者电流过大时切断电路.起到保护电池的作用。控制电路位于电芯和笔记本电脑主板之间,主要分为保护电路和电池能源管理电路(进行电池组与主机通讯及电池使用情况的管理)两部分。 bq2040电池能源管理集成电路可以用来精确记录独立电池组或安装状态电池的电量,它支持镍镉(NiCd)电池、镍氢(NiMH)电池、锂离子(Li-ion)电池的容量测量,bq2040采用电源系统管理Vei1.0(SMBus)协议,支持智能电池数据管理命令(SBData)和智能电池充电控制(SBData)功能,通过串行接口可以测试电池充电状态、剩余电量、放电剩余时间、电池材料等信息。 电池状态可用4位LED形象地来表示,通过内部计数器和温度传感器估算自放电程度,也通过放电周期来校准和更新电池实际容量,外接EEPROM内写有初始化程序,控制电池的管理工作。 2 引脚定义 bq2040引脚排列如图1所示,引脚功能如下: Vcc:供电输入。 ESCL:串行存储器时钟端,用来在bq2040和外部非易失存储器间锁定数据传输。 ESDA:串行存储器数据和地址I/O端,双向传输,用来在bq2040和外部非易失存储器间传输数据和地址。 LED1~LFD4:LED显示输出端,每个输出都可以接一个LED,指示电池的状态。 VSS:接地端。 SR:检测电阻输入端,接检测电阻和电池负极,用SR引脚和VSS地间的电压降(VSR)说明电池的充放电活动情况。 DISP:显示控制输入,DISP高电平时LED显示无效;DISP悬空且充电电流大于100 mA时LED显示充电状态;DISP低电平时,LED显示有效。 SB:第二电池输入端。 PSTAT:保护状态输入端。 SMBD:SM数据总线。 SMBC:SM时钟总线。 REF:参考电压端,为场效应管稳压输出提供参考电压。 VOUT:供电输出端。 3 功能描述 3.1 操作过程 bq2040通过检测充电电池的充放电量来确定电池容量。 图2所示为bq2040采用LED进行电池容量显示的典型应用电路。 3.2 门限电压 监测VSR可监测充放电流,通过SB脚检测电池容量,电池容量通过分压电阻网络确定。 3.3 复位 刚接上电池组,bq2040开始复位。 (1) 写0x0000到最大误差标志MaxError(0x0c)。 3.4 温度 3.5 布局考虑

Charging Nickel-Metal-Hydride Batteries Know how to apply the correct charge to moderate heat and prevent overcharge. The charge algorithm for NiMH is similar to NiCd with the exception that NiMH is more complex. The NDV to detect full charge is faint, especially when charging at less than 0.5C. A mismatched or hot pack reduces the symptoms further. Comments are intended for "commenting," an open discussion amongst site visitors. If you have a question, require further information, have a suggestion or would like to report an error, use the "contact us" form or email us at: Comments On May 3, 2011 at 6:50pm farhan wrote: please i need information about the white powder released ffrm nickel mh batteries within next 12 hors before 3pm 4th may 2011..please tell me what that powder chemical is and about crystalline or amorphous.. On May 16, 2011 at 12:07pm JMD wrote: So.. what is the recommended C-rate for charging NiMH??? On September 9, 2011 at 9:11pm Edward wrote: On September 10, 2011 at 12:52am Jeffrey wrote: Hi Ed

18650 battery test 2011 18650 battery test 2011 A 2012 test can be found here In this test I have measured many different 18650 batteries and collected the data in bar graphs and curves. The above picture shows most of the cells I have tested. Capacity: Measured capacity at 0.2 ampere discharge rate (This is the average from the two tested cells). This chart show the average capacity of the tested cells. This chart show the average energy of the tested cells. In this chart I have taken the difference between 0.2 and 2 ampere energy bar and calculated the change in percent of total energy ((Energy@0.2A - Energy@2A) /Energy@0.2A). Physical dimensions 18650 batteries are not all the same size, they are supposed to be 18 mm in diameter and 65 mm long, but due to the added protection circuit they are up to 5 mm longer. Combined discharge curves These curves can be very hard to read, due to the many cells in one chart. 0.2 ampere discharge 0.5 ampere discharge 1 ampere discharge 2 ampere discharge 5 ampere discharge Notes

How do I determine the maximum current for charging a li-ion battery? Charging Nickel-Cadmium Batteries Learn how to maximize charge, minimize heat and reduce memory. Battery manufacturers recommend that new batteries be slow-charged for 16 to 24 hours before use. A slow charge brings all cells in a battery pack to an equal charge level. Battery manufacturers do not fully format the batteries before shipment. Most rechargeable cells include a safety vent that releases excess pressure if incorrectly charged. Full-charge Detection by Temperature Full-charge detection of sealed nickel-based batteries is more complex than that of lead acid and lithium-ion. Advanced chargers no longer rely on a fixed temperature threshold, but sense the rate of temperature increase over time, also known as delta Temperature over delta time, or dT/dt. Chargers relying on temperature inflict harmful overcharges when a fully charged battery is removed and reinserted. Full-charge Detection by Voltage Signature Advanced chargers terminate charge when a defined voltage signature occurs. Last updated 2015-03-30

On notebook batteries controlled by the BQ2092 and BQ2040 (and maybe others) On notebook batteries controlled by the BQ2092 and BQ2040 (and maybe others) Contents Downloads Battery refurbishment programs (a small download, linux required) - you'll need a Linux system with i2c 2.6.4 or higher, with the appropriate modules loaded.A bootable battery refurbishment CD (no hassle, a 7.5MB download) There are several download sites (a file this large cannot be placed at SWEB.CZ for free): Thanks to everyone who has provided storage space. The compressed .tgz archive can be opened with WinZip, yielding an .iso CDrom image. It contains a minimalistic bootable Linux based on RedHat 8, text mode (no X) with the i2c-progs packaged in, a shell script presenting a menu, some basic goodies to facilitate freestyle improvising (vim, mc, basic system environment, five unrestricted shell consoles at ALT+F2 to ALT+F6), a bit of documentation. Either way, you'll need to solder the necessary wiring probes for the parallel port (see below). SMBus - external port (A photo) (A photo)

Micro-Controled Multi-Functions SmartCharger for (Li-Ion 7.4-14.8V / NiMH 1.2V-10.8V) Battery Packs As a consumer, you will easily find low price rechargeable batteries, such as AA, AAA, C, SC (Sub C), D, 9V, CR123A, button battery, RC batteries , UL approved smart chargers and battery management system (BMS) for all types of batteries If you want to know more about the products we already carried, check out our links section in the left-hand column. Thank you for visiting our online shop. We have great products at very low and reasonable prices. Battery as a Buffer to Assist the AC Power Supply Battery University BU-406: Battery as a Buffer The main purpose of a stationary battery is to provide power during power outage. A battery bank can also provide supplementary power during high-traffic periods. In essence, the battery acts as a buffer to assist the AC power supply when so needed. The term “AC power supply” refers to the unit that provides electrical power to the system and charges stationary batteries. Cellular repeater towers are an example where the battery serves as a buffer to bridge heavy usage times. When relying on the battery as buffer, make certain that the battery has enough time to charge between peak periods. Last updated 2011-02-12 *** Please Read Regarding Comments *** Comments are intended for "commenting," an open discussion amongst site visitors. If you have a question, require further information, have a suggestion or would like to report an error, use the "contact us" form or email us at: Previous Lesson Next Lesson Basics You Should Know

The Anatomy of a Protected Battery The Anatomy of a Protected LiIon Battery A protected battery will (hopefully) include the following protections: PTC, protect against over temperature and indirectly over current and will automatic reset. CID or pressure valve, will disable the cell permanently if the pressure is to high in the cell (Can be due to over charge). PCB will protect against over discharge, over charge and over current, depending on design the PCB will reset automatic or when placed in a charger. Unprotected batteries are missing the PCB protection, but usual has the PTC and CID. The above drawing illustrates how a protected cell is build. The battery is a 18650 battery, with this name it is supposed to be 18 mm in diameter and 65 mm long. The holes in the plus pole of the battery is the exhaust from the pressure valve in the battery, this can be seen on many types of batteries. Note the narrowing on the backend of the battery and it also looks like there is something on the side of the battery. Notes

How to repair IBM thinkpad 240 batteries (02K6608,02K6606) Back to resources How to repair IBM thinkpad 240 batteries (02K6608,02K6606) Caution Li-ion cells are dangerous be very careful when disassembling your battery pack - only do this if you know what you're doing this page is meant as an educational guide not a how to. If you follow the procedure here and kill yourself I will consider it a gift to the gene pool. You are on your own. Anything stupid that your do is your own fault. My IBM thinkpad 240 battery (02K6608,02K6606) died the other day. The battery is quite clever it has a bq2040 smart battery interface chip, which in turn has an eeprom in which it keeps track of the battery. First the actual battery board prepared in the usual way using chalk mix because IC numbers don't scan. Large version Click on a chip for more info. Connections to examine/modify EEPROM. How to read eeprom. The reading procedure is in the 24C01 datasheet and the data format is in the bq2040 datasheet. Interface ckt