Except for use as a normal Battery Charger, this circuit is perfect to ‘constant-charge’ a 12-Volt Lead-Acid Battery, like the one in your flight box, and keep it in optimum charged condition. This circuit is not recommended for GEL-TYPE batteries since it draws to much current.
Lead Acid Battery Charger #1 - [Link]
Josh @ imsolidstate.com describes how he converted a battery charger to spot welder. This spot welder has digital control circuit and current monitoring to precise control the welding procedure. Source code and schematics are available on the link below.
Build a spot welder from a battery charger - [Link]
The YoGen® by Easy Energy, Inc., is a slim pocket-sized, durable, hand powered electric charger that produces a previously unmatched level of charging power when driven by the repeated pulling of a cord, in a way which somewhat resembles the action of a Yo-Yo.
YoGen: Pull cord to charge - [Link]
This is a tiny USB battery charger.With this tiny thing you can charge almost all devices that are charged via USB, like iPods or mobile phones, with only two AA-Cells.most important compenent of the cicuit presented in the next steps is the “LT1301″. This is a small step up converter for to build switching mode power supplys with only a few external components.
Portable USB Charger - [Link]
The bq2404x series of devices are highly integrated Li-ion linear chargers devices targeted at space-limited portable applications. The devices operate from either a USB port or AC adapter. The high input voltage range with input overvoltage protection supports low-cost unregulated adapters.
BQ24040: Single Cell Li-Ion Battery Charger With Auto Start - [Link]
Fast charger for NiCd, NiMh, LiPo and SLA batteries
The Universal Charger usage is very easy but some point must be strictly followed in order to avoid any problem in battery and charger management. First read the charger documentation, then follow these recommendations in order to have a good charger usage.
Universal Charger – [Link]
In this project there are actually 3 chargers combined in a single PCB, each charger having an output voltage of 4.2V. You can cascade them to become charger fit for 2 or 3 cels Lipo pack. The transformer used is 3 x 8 VAC. As more and more devices are powered with LiPo batteries such a charger could come handy some day.
DIY LiPo Charger - [Link]
Here is the simple Lithium Ion Battery Charger. Lithium Ion batteries pack a lot of power by weight compared to other types. There are 2 things that need to be handled differently than nicad on NiMH 1. They cannot be used as a direct substitute (even if they look like other AA’s) since they run at about 3.6 (or so) volts.2. They cannot be charged in the same way as nicad or NiMH. [via]
Lithium Ion Battery Charger – [Link]
NiMH cells are still very popular energy source in portable media like digital cameras, clocks, various players, etc. They provide quite good energy density for reasonable price. Charging current of NiMH cells should be about 10% of their rated hourly capacity. And charging time should not exceed 14 hours. Following charger is what it does. [via]
AVR based NiMH charger - [Link]
Portable USB charger’s will always be handy, lets face it these days every gadget around us has USB charging capabilities. This is a very basic and simple project, and cheap too. Maybe its time for you to build your own diy portable USB charger.
DIY portable USB charger - [Link]