A booster is a portable stand-alone power source for car battery. This device operates due to lead-acid batteries, the working medium of which is a thickened electrolyte. Electrolytes of this kind are not prone to leakage, even if the booster batterie is turned over. Due to this, it can be transported in the most convenient position. All boosters are hermetic, equipped with handles for carrying, have indicators and additional functions. Many boosters have the function of switching from 12V to 24V. Switching is carried out by changing the connectors.