Battery’s Serial connection

Portable equipment with high-energy needs is powered with battery packs in which two or more cell are connected in series. Figure 1 shows a battery pack with four 1.2-volt cells in series. The nominal voltage of the sony vgp-bps8 battery string is 4.8V.

Figure 2 illustrates a battery pack in which cell 3 produces only 0.6V instead of the full 1.2V. With the depressed operating voltage, the end-of-discharge point will be reached sooner than with a normal pack and the runtime is severely shortened.Once the equipment cuts off due to low voltage, the remaining three cells are unable to deliver the stored energy. Cell 3 could also exhibit a high internal resistance, causing thestring to collapse under load hp Pavilion dv9000 Battery. A weak cell in a battery string is like a blockage in a garden hose that restricts water flow.Cell 3 could also be shorted, which would lower the terminal voltage to 3.6V, or be open and cut off the current. A battery is only as good as the weakest cell in the pack.

Adding cells in a string increases the voltage but thecurrent remains the same.High voltage batteries have the advantage of keeping the conductor and switch sizes small. Medium-priced industrial power toolsrun on 12V to 19.2V toshiba pa3634u-1bas batteries; high-end power tools go to 24V and 36V to get more power than toshiba pa3465u-1brs Battery. The car industry will eventuallyincrease the starter-light-ignition (SLI) battery from 12V (14V) to 36V, better known as 42V. These batteries have 18 lead-acid cells in series. The early hybrid cars are running on 148V batteries. Newer models feature batteries with 450-500V; mostly on nickel-based chemistry. A 480-volt nickel-metal-hydride battery has 400 cells in series. Some hybrid cars are also experimenting with lead acid.

42V car batteries are expensive and produce more arcing on the switches than the 12V. Another problem with higher voltage batteries is the possibility of one cell failing. Similar to a chain, the more links that are connected in series, the greater the odds of one failing dell inspiron 6400 battery. A faulty cell would produce a low voltage. In an extreme case, an open cell could break the current flow. Replacement of a faulty cell is difficult because of matching. The new cell will typically have a higher capacity than the aged cells.