How do I connect if I have dual engines?
You do not need two starter batteries just because you have two engines.
A regular 75 Ah battery has a power of about 600 A, and can start both engines, if you wait a minute after the start of the first engine, then the battery is ready to start the next engine without any problems.
Use the extrs space for an additional consumer battery instead. If 600 A is not enough to start your engines with, you can buy a starter battery with higher starting current, such as Tudor Maxxima.
In our diagram to the right, we have fully utilized the boat's generator capacity.
Avoid having a generator for the starter battery and another for the consumer batteries, as one generator will be unused for most of the time. Engines get off well below 1 Ah per start. The charging requirement of the starter battery is therefore very small.
On the other hand, the starter motor requires high power, ie high current; A 200 hp diesel draws approximately 600 A. The high current causes the voltage in the starter battery to drop so much that the starter battery takes the most charge current of all batteries immediately after engine start.
Therefore, no additional charging of the starter battery is required.
