The 12v system has been upgraded. The old system had a too small solar panel and the 12v batteries were very old, always struggling to hold a charge.
It was time to replace the batteries and add more solar power.
1) The batteries have been replaced with a new set of Trojan 6v T-105 Deep-Cycle.
2) An extra panel has also been added to the existing 12v 50W panel. I installed a 12v 150W solar panel from solartronics, giving me a total of 200W STC.
This increase in charging required me to also upgrade the control equipment. The picture below is showing the new 12v Control panel, and on the left the Xantrex Charge Controller.
The new control panel consists of 2 x 100 Amp Voltage-Current-Power-Energy meters as detailed below.
and a voltage meter, displaying both the voltage and percentage capacity.
The power meters have been installed, one measuring the charging current while the 2nd meter measuring the load current. Both charge and loads are protected by fuses.
Due to the higher charging current, I installed a Xantrex charge controller to protect against overcharging the Trojan Batteries. Details on the charge controller can be found here