Battery Management LITHIUM-ION BATTERY PROTECTION 3/4 CELL

The MAX1870A step-up/step-down multichemistry battery charger charges with battery voltages above and below the adapter voltage. This highly integrated charger requires a minimum number of external components. The MAX1870A uses a proprietary step-up/stepdown control scheme that provides efficient charging. Analog inputs control charge current and voltage, and can be programmed by the host or hardwired.The MAX1870A accurately charges two to four lithiumion (Li+) series cells at greater than 4A. A programmable input current limit is included, which avoids overloading the AC adapter when supplying the load and the battery charger simultaneously. This reduces the maximum adapter current, which reduces cost. The MAX1870A provides analog outputs to monitor the current drawn from the AC adapter and charge current. A digital output indicates the presence of an AC adapter. When the adapter is removed, the MAX1870A consumes less than 1µA from the battery.The MAX1870A is available in a 32-pin thin QFN (5mm x 5mm) package and is specified over the -40°C to +85°C extended temperature range. The MAX1870A evaluation kit (MAX1870AEVKIT) is available to help reduce design time.ApplicationsHandheld TerminalsNotebook and Subnotebook Computers

The MAX1874 charges a single-cell Li+ battery from both USB and AC adapter sources. It also includes battery-to-input power switchover, so the system can be powered directly from the power source rather than from the battery.In its simplest application, the MAX1874 needs no external MOSFET or diodes, and accepts input voltages up to 6.5V; however, DC input overvoltage protection up to 18V can be added with a single SOT PFET.On-chip thermal limiting simplifies printed circuit board (PCB) layout and allows optimum charging rate without the thermal limits imposed by worst-case battery and input voltage. When the MAX1874 thermal limit is reached, the charger does not shut down but simply reduces charging current.Ambient or battery temperature can be monitored with an external thermistor. When the temperature is out of range, charging pauses.Other features include an active-low CHG output to indicate when battery current tapers below a predetermined level. DC power-OK (active-low DCOK), USB power-OK (active-low UOK), and power-on (PON) outputs indicate when valid power is present. These outputs drive logic or power-selection MOSFETs to disconnect the charging sources from the load and to protect the MAX1874 from overvoltage.The MAX1874 contains no logic for communication with the USB host. It must receive instructions from a local microcontroller. The MAX1874 is available in a 16-pin 5mm x 5mm thin QFN package and operates over the -40°C to +85°C temperature range.ApplicationsCell PhonesDigital CamerasPDAsWireless Appliances

Sealed Lead Acid Battery 12V 7.2AH .187" TAB

The MAX745 provides all functions necessary for charging lithium-ion (Li+) battery packs. It provides a regulated charging current of up to 4A without getting hot, and a regulated voltage with only ±0.75% total error at the battery terminals. It uses low-cost, 1% resistors to set the output voltage, and a low-cost N-channel MOSFET as the power switch.The MAX745 regulates the voltage set point and charging current using two loops that work together to transition smoothly between voltage and current regulation. The per-cell battery voltage regulation limit is set between 4V and 4.4V using standard 1% resistors, and then the number of cells is set from 1 to 4 by pin-strapping. Total output voltage error is less than ±0.75%.For a similar device with an SMBus™ microcontroller interface and the ability to charge NiCd and NiMH cells, refer to the MAX1647 and MAX1648. For a low-cost Li+ charger using a linear-regulator control scheme, refer to the MAX846A.ApplicationsCell PhonesDesktop Cradle ChargersHandheld Instruments (PDAs, Palmtops)Li+ Battery PacksNotebook Computers

The MAX846A is a cost-saving multichemistry battery-charger system that comes in a space-saving 16-pin QSOP. This integrated system allows different battery chemistries (Li-Ion, NiMH or NiCd cells) to be charged using one circuit.In its simplest application, the MAX846A is a stand-alone, current-limited float voltage source that charges Li-Ion cells. It can also be paired up with a low-cost microcontroller (µC) to build a universal charger capable of charging Li-Ion, NiMH, and NiCd cells.An internal 0.5%-accurate reference allows safe charging of Li-Ion cells that require tight voltage accuracy. The voltage- and current-regulation loops used to control a low-cost external PNP transistor (or P-channel MOSFET) are independent of each other, allowing more flexibility in the charging algorithms.The MAX846A has a built-in 1%, 3.3V, 20mA linear regulator capable of powering the µC and providing a reference for the µC's analog-to-digital converters. An on-board reset notifies the controller upon any unexpected loss of power. The µC can be inexpensive, since its only functions are to monitor the voltage and current and to change the charging algorithms.ApplicationsCell PhonesDesktop Cradle ChargersHandheld Instruments (PDAs, Palmtops)Li+ Battery PacksLi+-Ion/NiMH/NiCd Multichemistry Battery ChargersNotebook Computers

Electronic Battery AA 2.1Ah AXIAL LEADS

Cylindrical Battery Contacts, Clips, Holders & Springs BATTERY CONTACT

Electronic Battery 2/3AA 1.65Ah POL TAB

Coin Cell Battery Holders 20MM BATTERY HOLDER DUAL