Lithium ion battery charger implementation using C8051F300 app note(PDF!) from Silicon Labs.
Driven by the need for untethered mobility and ease of use, many systems rely on rechargable batteries as their primary power source. The battery charging circuitry for these systems is typically implemented using a fixed-function IC to control the charging current/voltage profile.
The C8051F30x family provides a flexible alternative to fixed-function battery chargers. This application note discusses how to use the C8051F30x family in Li-Ion battery charger applications. The Li-Ion charging algorithms can be easily adapted to other battery chemistries, but an understanding of other battery chemistries is required to ensure proper charging for those chemistries.
App note: Lithium ion battery charger using C8051F300 - [Link]
The NEW Solar BMS charger for LiFePO4 or any other Li-ion battery and used for OffGrid House, RV or boats, with wireless datalogging.
Solar BMS (Solar Battery Management System)is a solar charge controller designed to replace the Lead Acid solar charge controllers most people use today in Offgrid, RV, Boats and multiple other applications with 12V and 24V systems. Solar BMS can be used with 3 up to 8 Lithium cells (any type) or supercapacitors. The new SBMS100 will have multiple improvements over the first generation SBMS4080 see further for details.
120A Solar BMS charger LiFePO4, Li-ion OffGrid,RV with WiFi - [Link]
by T.K. Hareendran:
Here is a tried and tested sample circuit of a Li-Ion battery charger that can be used to charge any 3.7V Li-Ion battery using a 5VDC (USB, Solar Panel…) power supply. At the heart of the circuit is one microchip MCP73831, available in SOT-23-5 package. MCP73831 is a highly advanced linear charge management controller for use in space-limited, cost-sensitive applications. This IC employs a constant current/constant voltage charge algorithm with selectable preconditioning and charge termination.
3.7V Li-Ion Battery Charger Circuit - [Link]
Standalone Linear Li-Ion battery charger with thermal regulation in ThinSOT application note (PDF!) from Linear:
The LTC4054 is a single cell lithium-ion battery charger using a constant-current/constant voltage algorithm. It can deliver up to 800mA of charge current (using a good thermal PCB layout) with a final float voltage accuracy of ±1%. The LTC4054 includes an internal P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external current sense resistor is required; thus, the basic charger circuit requires only two external components. Furthermore, the LTC4054 is capable of operating from a USB power source.
App note: Standalone Linear Li-Ion battery charger with thermal regulation - [Link]
by BinksBrew @ instructables.com:
For a long time I’ve had old back up cell phones taking up space in my desk drawer. I was curious if I could put any of these old phones to some use. I can’t just throw them away so I decided to try and re-purpose one of them as a portable charger for my current smart phone.
Portable Charger for your Smartphone - [Link]
by DIY Hacks and How Tos @ instructables.com:
A “Joule Thief” is a simple voltage booster circuit. It can increase the voltage of power source by changing the constant low voltage signal into a series of rapid pulses at a higher voltage. You most commonly see this kind of circuit used to power LEDs with a “dead” battery. But there are many more potential applications for this kind of circuit.
In this project, I am going to show you how you can use a Joule Thief to charge batteries with low voltage power sources. Because the Joule Thief is able to boost the voltage of a signal, you are able to charge a battery with a power source whose output voltage is actually lower than the battery itself.
This lets you take advantage of low voltage power sources such as thermoelectric generators, small turbines and individual solar cells.
Joule Thief Low Voltage Battery Charger - [Link]
kraftwerk opens up a whole new dimension in freedom and independence when it comes to supplying your mobile electronic devices with energy. Why? Because kraftwerk enables you to generate your own energy using a small, handy device – in such large amounts that you can run your iPhone, tablet, or even your GoPro camera for weeks!
The Kraftwerk Fuel Cell - [Link]
Li-Ion/Polymer Shunt battery charger system with low battery disconnect (PDF!) app note from Linear Technology:
The LTC®4071 allows simple charging of Li-Ion/Polymer batteries from very low current, intermittent or continuous charging sources. A near zero current low battery latching disconnect function protects even the lowest capacity batteries from deep discharge and potentially irreparable damage. The 550nA to 50mA operating current makes charging possible from previously unusable sources. With its low operating current the LTC4071 is well suited to charge low capacity Li Ion or thin film batteries in energy harvesting applications. The unique architecture of the LTC4071 allows for an extremely simple battery charger solution, requiring just one external resistor.
Li-Ion/Polymer Shunt battery charger system with low battery disconnect - [Link]
by Solarcycle @ instructables.com:
Power Stacker is a portable, modular, USB rechargeable lithium-ion battery pack. Stack them together for power hungry projects or separate them for smaller projects with this modular system. The Gerber, BOM, and .STL files are available below.
Power Stacker does what other USB rechargeable batteries have failed to do, and that’s the ability to combine together for increased battery capacity or separate in to many small batteries for smaller projects. You can literally use the same Power Stacker batteries for many years across many applications!
Stackable USB Rechargeable Battery System - [Link]
by Jim @ jimlaurwilliams.org:
I got a couple of cheap ($1.29) 1A USB LiPo chargers since I’m doing more and more LiPo/LiIon powered stuff. I mostly discharged a recycled 18650 cell for a test load and it looks like it does charge at nearly 1A. Two LEDs – red charging, green (mine is blue) fully charged. Seems like a pretty ideal cheap device.
Cheap USB LiPo charger notes - [Link]