CI DA ATMEL balanciamento de celula ativa

[lelles]

http://www.elektor.com/news/active-cell-balancing-for-e-vehicle-li-ion.1282590.lynkx?utm_source=UK&utm_medium=email&utm_campaign=news

postei este tópico p/ quem dominar este asunto me explique melhor,já que pelo que eu entendí parece que é um circuito novo da atmel que gerencia varias celulas no balanciamento inverso do que os balanciadores atuais fazem hoje,em vez de descarregar{via resistores} a celula com alta voltagem ele carrega a que esta com baixa voltagem{via capacitores} por favor se estiver errado me corrijam. um abraço

para quem não consegui abrir o link segue texto da revista elektor

Atmel announced that its new battery management circuit ATA6870 featuring active cell balancing with capacitors or inductors for high-cell-count Li-Ion batteries supporting supply voltages up to several hundreds volts such as used in electrical/hybrid vehicles, e-bikes or uninterruptible power supplies.

The advantage of an active cell balancing is that it avoids the energy loss as occurs with passive balancing methods. The charge is transferred with a shuffle capacitor or inductor from one cell to another with nearly no losses, leading to higher efficiency and a longer battery life. In passive methods, cells of large battery stacks are balanced by discharging overcharged cells through a resistor.

In a typical battery pack, no cell is identical to another. The cells differ in the state-of-charge, self-discharge rate, cell impedance and capacity, and aging. After several charge and discharge cycles, this may result in increased voltage differences between the individual cells. This effect will impact the cells where several cells may no longer be properly charged, with the possibility of weak cells being over or undercharged. This will decrease the overall lifetime of a battery. Active balancing is a perfect method to constantly ensure that all the cells have the same state-of-charge.

Atmel’s ATA6870 circuit monitors up to six battery cells and can be stacked up to 16 times. For the highest communication robustness between the stacked ICs, the IC features level shifters based on current sources. In addition, the ATA6870 includes an 8-bit checksum monitor that helps further increase data communication robustness.

The new IC provides a dedicated AD converter for each battery cell to be monitored. This enables the device to simultaneously measure the voltage of all cells within one battery string for precise state-of-charge determination of Li-Ion battery cells. The integrated power supply for the microcontroller can be stacked. Therefore, the current required to supply the microcontroller can be taken from the top cell and be fed back into the battery string's bottom cell. As a result, the microcontroller's current consumption will not cause any cell imbalance helping designers save expensive high-voltage devices. The on-board balancing capability can be used for various balancing techniques like passive balancing with a resistor or active balancing with a capacitor or an inductor.

Samples of Atmel’s new ATA6870 IC are now available in small QFN48 packages. Evaluation kits are available now to enable a quick-start with the IC to allow prototyping and testing of new battery designs immediately. Atmel also offers additional software for PCs and laptops with a graphical user interface to control and optimize high-cell-count battery stacks.

Elektor magazine has announced publication of a low-cost LiPo charge balancing monitor in its May 2010 issue.

[Sputnicker]

É a diferença entre balanceamento ativo e balanceamento passivo.

No balanceamento ativo, a célula que estiver mais descarregada é carregada até ficar igual às demais.
No balanceamento passivo, a célula descarregada serve de guia para as demais, e após recarregar é SUPOSTO que elas fiquem iguais.