This charger is an automatic one that will prevent battery from overcharging. The circuit consists of two main parts a voltage and current regulator and a voltage monitoring circuit with a cutoff relay. When the battery voltage is below 12.6V the it’s charging and when voltage goes to 13.8 then charging process is stopped. [via]
Automatic battery charger – [Link]
This project shows how to power an AVR microcontroller from a single AA battery using a circuit that is controlled from the same microcontroller.
Powering AVR Microcontroller from AA battery – [Link]
The above pictured schematic diagram is just a standard constant current model with a added current limiter, consisting of Q1, R1, and R4. The moment too much current is flowing biases Q1 and drops the output voltage.
Lead Acid Battery Charger #2 - [Link]
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]
Smart Battery Meter meaures the charge condition of LEAD-ACID batteries and uses a multicolor LED array to show remaining charge.
The Smart Battery Meter measures the “state of charge” of a 12 volt or 24 volt sealed, lead-acid battery system. It uses a multi-color array of LEDs to give an instant visual indicator of the remaining charge, sort of like a gas gauge.
You can buy a kit or assembled unit from the site below. Instructions are not online yet, but you can email the author for more information.
Smart Battery Meter - [Link]
Using Arduino True Battery Capacity Tester you are able to measure the charging capacitance of Li-Ion/NiMH/NiCD/Pb batteries and display results on character LCD screen or aquire full discharge characteristic graph on PC. Tester supports auto battery type detection and discharge takes from 30-120 minutes to complete, giving you an indication of battery’s quality.
Arduino True Battery Capacity Tester (Li-Ion/NiMH/NiCD/Pb) - [Link]
Knut Karlsen at blog.bareknut.no writes:
At home i always have some batteries lying around, either rechargeable or normal ones. Usually they are empty, but i’d like them to be always fully charged. I could use a normal charger and there is a lot of solar devices that charge rechargeable batteries. I wanted it simpler; why hasn’t anyone made a battery with integrated solar cells? The idea of the “SunCat” batteries where born.
Solar cell batteries - [Link]
While scientists are finding ways to make batteries smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the powered devices themselves. Good news: Jae Kwon, assistant professor of Electrical and Computer Engineering has developed a nuclear energy source that is smaller, lighter and more efficient. Reportedly Kwon’s radioisotope battery can provide power density that is six orders of magnitude higher than chemical batteries.
Your next battery may be nuclear - [Link]
Alex at Tinkerlog writes:
For my latest projects I used a lot of single cell LiPo batteries. They are really nice. High power density, low self-discharge, no memory effect and they can deliver quite an amount of current. But LiPo battery handling is a bit more complicated than other rechargeable batteries. You have to take care of under voltage and over charging as that may destroy the battery.
I used the Sparkfun LiPoly charger, based on MAX1555, for some time and it works really well. The only thing I missed was a way to control the current. After some research I decided to try another chip, the Microchip MCP73833. [via]
LiPoly charging with MCP73833 - [Link]
I recently ordered a $37 battery desulfator kit. It looks like a pretty simple device that sends pulses to lead acid batteries to help clean the battery plates. There are many success stories on the net about resuscitating essentially “dead” lead acid batteries. Since we have two electric vehicles and live off grid we have a lot of motivation to take care of our batteries. I’ve seen kits that sell for hundreds of dollars, but this 555 based kit seems to kick out a lot more juice than the fancy ones with wimpy solar panels. [via]
Desulfator kit - [Link]