In such installations, it is important that the individual battery groups do not influence each other and are constructed appropriately.
This of course means that the charging system also has to be separated. However, the charging process is more complicated because either the alternator, generator or charger must recharge the batteries individually again.
When selecting diodes/relays, the max. possible charge current must be considered - for example, if your alternator is rated at 50-70 A, the power of the battery isolator would be rated at 70 A.
Installing an isolation diode is the easiest thing to do. This robust solution provides the ability to charge up to three batteries simultaneously from an alternator and/or battery charger without connecting the batteries together. As a result, the charge current becomes isolated, meaning a mutual discharge of the starter batteries and the batteries that power the boat's lighting and bowthruster is prevented.
In "normal" isolators, this type of construction results in a voltage drop between 0.3 and 1.2 V. This sounds rather small - but the result is an incomplete charge, wherein the batteries are not charged 100%. The isolators that we supply are Schottky diodes, used with a voltage drop of 0.7 V.
Isolators with integrated compensatory diodes. They reduce the voltage drop to almost 0.005 V. For these diodes, a cable from D + alternator on the diode-splitter needs to be installed.
The use of electronic charging current distributors. The voltage drop in these distributors is negligible and additionally provides some of these devices with various settings for undervoltage and overvoltage protection, primary charge for the starter battery etc.
The use of special relays, which are specially adapted for the use of a battery charge. These devices often offer additional features such as jump-start, undervoltage and overvoltage protection etc.
The simplest version of charging current distribution is to use a battery changeover switch. In this case, however, there is a danger that incorrect operation in the switch position "both" (1 + 2) may lead to unintentional discharge of both batteries.