4.8 Large system busbars In systems that contain inverter/chargers and MPPTs, that all connect to a busbar, it is important to alternately connect the inverter/chargers and MPPT to the busbars. This will reduce the current flowing through the busbars. And all MPPTs should have approximately the same cable length.
If the systems has only one battery bank you should connect the battery bank in the middle of the busbars. But in case of several parallel battery banks, they should also be distributed along the busbars.
4.9 Voltage sensing and compensation
Voltage sense is a feature that will compensate for cable losses during charging. This will ensure batteries are charged with the correct voltage. This feature generally will only compensate for voltage losses up to 1V. If the losses in the system are bigger than 1V (i.e. 1 V over the positive connection and 1 V over the negative connection), the charger or inverter/charger will reduce its charge voltage in such a way that the voltage drop remains limited to 1 V. The reason behind this is, that if the losses are bigger than 1 Volt, the battery cables are too thin and are unable to carry a large current and therefore the charge current needs to be reduced. Voltage sense also be used to compensate for voltage losses when diode splitters are used. A diode splitter has a 0.3 V voltage drop over the diode. Some products such as inverter/chargers or large chargers have voltage sense build in. For other products, such additional equipment might be needed such as the smart battery sense or the Smart VE.Bus dongle. • If the product has a voltage sense terminal two sense wires can be connected from the V-sense terminal directly on the battery positive and negative terminal or distribution. Use wire with a cross- section of 0,75mm². • In case of the MultiPlus II connect the VE.Bus smart dongle to the battery and connect the dongle via a RJ45 cable to the MultiPlus II.
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