Final answer:
An RV's 12-V system typically uses a lead-acid battery, due to its cost-effectiveness and ability to provide the high current needed for the vehicle's systems.
Step-by-step explanation:
The correct answer is that the type of battery used in an RV's 12v system is typically a lead-acid battery. This kind of battery is chosen because it is inexpensive and capable of producing the high current necessary for starting engines and powering other electrical systems within vehicles.
Each cell in a lead-acid battery produces about 2 V, so six cells are usually connected in series to form a 12-V system.
Despite their weight and the presence of a caustic liquid electrolyte, lead-acid batteries are preferred due to their high current density and low cost.
These batteries are found in many vehicles, including semi-tractor trucks which may use multiple 12-V batteries in parallel or series, depending on the required voltage and current needs for starting and running the vehicle's systems.