jyoti bhatia
Last Activity: 6 Years ago
If higher currents are needed and larger cells are not available or do not fit the design constraint, one or more cells can be connected in parallel. Most battery chemistries allow parallel configurations with little side effect.A cell that develops high resistance or opens is less critical in a parallel circuit than in a series configuration, but a failing cell will reduce the total load capability. It’s like an engine only firing on three cylinders instead of on all four. An electrical short, on the other hand, is more serious as the faulty cell drains energy from the other cells, causing a fire hazard. Most so-called electrical shorts are mild and manifest themselves as elevated self-discharge.
A total short can occur through reverse polarisation or dendrite growth. Large packs often include a fuse that disconnects the failing cell from the parallel circuit if it were to short.
A weak cell will not affect the voltage but provide a low runtime due to reduced capacity. A shorted cell could cause excessive heat and become a fire hazard. On larger packs a fuse prevents high current by isolating the cellIf cells are joined side by side, they are said to be connected in parallel. Components that are connected in parallel provide alternative pathways for current flow. When cells are connected in parallel, the total voltage they provide does not change, so two or more 1.5 V cells connected in parallel still only provide a total voltage of 1.5 VIn a parallel circuit there is more than one path for the current to flow along. When cells are connected in parallel the total value of the cells is the same as each individual cell. For two 1.5 V cells in parallel, the voltage stays at 1.5 V, but the life of the battery is doubled.