This battery charger charges a NIMH 5-pack battery used in the BiPed robot in less than 1 hour, and charges the 10-pack NiCd used in the Snuf robot in about 30 minutes. To prevent overheating of the battery, the charging current is turned off when the slope of the battery-voltage turns from positive into negative. A second termination-criterion of the charging process is provided for safety: the charge time is limited to about 1 hour.

The electric model aircraft and car industries have produced a bewildering array of field chargers for NiCd motor battery packs. These range from simple 6 or 7 cell chargers consisting of a resistor and mechanical timer, to more complex chargers with peak detection, cycling, and the ability to handle 36 cell packs.

This is a charger for lithium ion batteries which takes its power from the USB port of a computer. It uses the MCP73861 or MCP73863 Li-ion battery charger chip manufactured by Microchip. Microchip MCP73861 or MCP73863 are advanced, fully-integrated, single-cell Li-Ion/Li-Polymer charge-management devices allow these peripherals to utilize the full power of the USB port.

This instructable will show you how to make your own solar battery charger from very simple components. It is taken from my documentation provided with a kit I supply - you should easily be able to source the same components yourself of course.

Batwatch is a simple monitor for a solar panel battery charger, using an Atmel ATtiny13V. It periodically measures the charge current and battery voltage, and shows them by blinking two LEDs. I built this circuit into the plug of a VW solar charger panel that is used to prevent a discharge of the battery when a car is not used for some time. A modern car contains a large amount of electronics, and a quiescent current of 40-50mA (about 1Ah per day!) is considered "normal".

This cheap and easy to build NiCd/NiMH Battery Charger is suitable for automatically charging a wide range of batteries for many applications. Proper chargers are usually expensive and cheap chargers supplied with the original equipment often incorrectly charge the cells and dramatically shorten their life.

This is a MAX1811 based USB charger that can handle both Lithium Ion and Lithium Polymer 3.7V battery. It requires very few external components and provides ability to select between 4.1v and 4.2v battery regulation for different types of LiPo batteries. You can select between either 100mA and 500mA current charging mode and LED provides the status of the charging.

The purpose of this project is to realize a Solar panel controller. Initially developed for a sailing boat, the target to reach was to control the level of charge and discharge and to protect a 12 volts lead battery connected to a 32 watts solar panel.

The accu cycler project presented here is an excellent solution for charging and discharging NiCd and NiMH accumulators for R/C modelers and others who make use of these accumulator types. With its performance it is very close to the many of the commercial products available on the market.

This is a NiCd/Ni-MH charger that can charge with constant current and automatic charge termination when the total voltage for all cells reach the setting voltage.

This is a Li-Po charger and balancer project for R/C hobby.The charger circuit is based on the circuit of Electron head and all folks in the DIY electronics topic on the rcgroups.com.

This is a simple to build charger for single 3.7V lipo battery. The heart of the charger is TL431 shunt regulator that controls the incoming current. Charger comes with a convenient charging LED indicator. As charging current goes down so does the intensity of the LED.

This cheap and easy to build NiCd/NiMH Battery Charger is suitable for automatically charging a wide range of batteries for many applications. Proper chargers are usually expensive and cheap chargers supplied with the original equipment often incorrectly charge the cells and dramatically shorten their life. This 'intelligent' charger was designed for high current and rapid charge applications such as cordless power tools and model racing cars. These battery packs are expensive and sometimes difficult to purchase. This charger uses the cell manufacturer's recommended charge method, to safely and quickly charge batteries.

« Atheros Drivers ASUS Eee Car Charger Building a 12v car charger for the ASUS Eee The ASUS Eee is a fantastic ultra-portable notebook with almost everything required for geeks (and nothing that isn’t). Plus it features fantastic build quality and is very well priced. If you live in New Zealand you can get them from DSE; at the time of writing they are the exclusive supplier. I worked out it’s the same cost as importing one once you include all the duties and tax, plus you get the advantage of a proper NZ-style mains charger. Anyway, being so small I thought it would be nice to be able to carry this around in the car. Unfortunately I couldn’t find a car charger available anywhere at the time so I decided to tackle the problem myself. As a bonus this provides an opportunity for an external high-capacity battery. Commercial Equivalent I thought at this stage it would be worth noting that a commercial car charger is now available for less than it cost me to build this from Expansys and is available in most countries (select your location on their site). It outputs 9.5v from 10-18v in at up to 2.5A I’d actually recommend it over the design here is it seems to perform better at lower voltages (that one works down to 10V). However I have kept this page up as a reference for those who enjoy tinkering. Design The charger included with the Eee is rated at 9.5v, 2.315A. There isn’t a fixed voltage regulator available for this exact voltage, so the circuit needed to be designed around an adjustable regulator. I decided to design the charger around the LM2576 “Simple Switcher” IC from National Semiconductor. There are tons of ICs like this available, many of which are a bit more efficient, however I selected this one because it is readily available and relatively cheap. It also has a lower drop-out voltage (~2V) than many other chips I looked at which is important when powering the device from a car or 12v SLA battery.

The Simple-Volt automatically detects the number of LiPo cells connected (assume charged pack) and continually monitors the battery voltage and compares it to the preset cutoff/warning voltage corresponding to the number of detected LiPo cells (9v for 3s, 12v for 4s and 15v for 5s... basically, 3 volts minimum per cell). When the battery voltage is greater than the cutoff voltage +1v, the Green LED will be on solid. If the battery voltage is > cutoff voltage+.5 but < cutoff voltage+1v, the Green LED will slowly flash. If the battery voltage is > cutoff but < cutoff+.5v, then the Red LED will begin flashing. If the battery voltage < cutoff voltage, both Green and Red LEDs will flash very fast while also emitting an intermittent beeping sound from the peizo alarm buzzer.

This is a MAX1811 based USB charger that can handle both Lithium Ion and Lithium Polymer 3.7V battery. It requires very few external components and provides ability to select between 4.1v and 4.2v battery regulation for different types of LiPo batteries. You can select between either 100mA and 500mA current charging mode and LED provides the status of the charging.

The MAX1551 and MAX1555 charge a single-cell 3.7V lithium-ion LiPo battery from both USB and AC adapter sources. They operate with no external FETs or diodes, and accept operating input voltages up to 7V. On-chip thermal limiting simplifies PC board layout and allows optimum charging rate without the thermal limits imposed by worst-case battery and input voltage. When the MAX1551 and MAX1555 thermal limits are reached, the chargers do not shut down, but progressively reduce charging current. The MAX1551 includes an active-low POK output to indicate when input power is present. If either charging source is active, active-low POK goes low. The MAX1555 instead features a active-low CHG output to indicate charging status. With USB connected, but without DC power, charge current is set to 100mA (max). This allows charging from both powered and unpowered USB hubs with no port communication required. When DC power is connected, charging current is set at 280mA (typ). No input-blocking diodes are required to prevent battery drain. The MAX1551 and MAX1555 are available in 5-pin thin SOT23 packages and operate over a -40°C to +85°C range.

This is a simple to build charger for single 3.7V lipo battery. The heart of the charger is TL431 shunt regulator that controls the incoming current. Charger comes with a convenient charging LED indicator. As charging current goes down so does the intensity of the LED.

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. After a bit of research, I came up with this design. Normally, you put in a specified current (about 0.2C) until 4.2 volts is reached. Then, you keep the voltage tightly regulated at 4.2 volts until the charge rate drops to 10 percent (about 0.02C). This design uses a regulated supply for both parts of the charging. Only the charging current is monitored since the supply voltage is maintained at 4.2 volts. The charging current is controlled using variable pulse width of the voltage feed.

The charger in this project is designed to charge two AA NiMH or NiCd cells of any capacity (as long as they are the same) at about 470mA. It will charge 700mAh NiCds in about 1.5 hours, 1500mAh NiMHs in about 3.5 hours, and 2500mAh NiMHs in about 5.5 hours. The charger incorporates an automatic charge cut-off circuit based on cell temperature, and the cells can be left in the charger indefinitely after cut-off.

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