By connecting batteries in series or parallel or series/parallel you can achieve the correct. Other important points to bear in mind when wiring boats or RV's:.
A series connection adds the voltage of the two batteries, but it keeps the same amperage rating (also known as Amp Hours). For example, these two 6-volt batteries joined in series now produce 12 volts, but they still have a total capacity of 10 amps.
If your boat came from the factory with only one battery, or with two batteries of. . one box if your batteries require you to make a series or parallel arrangement.
When connecting your batteries in Series you are doubling the voltage while maintaining the same capacity rating (amp hours). This might be used in a scooter, Power Wheels kids vehicle, or other applications. Just use a jumper wire between the negative of the first battery and the positive of the second battery.
For instance, below the two 6V 250Ah batteries pictured there, if wired in series parallel will give you a total of 12V at 500Ah. You can see several other example
There are several advantages to running two separate battery packs in a particular boat. One reason is if you need 12 cells but have other hulls that use only 6 .
Series and Parallel Battery Packs; Series Connections; Parallel Connections; Series/ Parallel Connections; Connecting Battery Chargers to Series and Parallel
Most marine batteries onboard boats today are of the lead-acid type.. . the marina talk about connecting batteries in series and connecting batteries in parallel.