12v System Upgrade

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

Product Review - Schneider Xantrex C35 Charge Controller

To protect my 2 x 6v Trojan Batteries, I bought and installed a Schneider Xantrex C35 Charge Controller.

The Controller is fairly easy to setup and it comes with a comprehensive manual. It's very difficult to get stuck with the installation or wrongly configure the controller.

I installed a dump load to divert excessive power. I still have to find or build an aluminium box for the diversion load heater, in fact right now it's just hanging underneath the controller.  The dump load can easily handle 12 amp at 12v.

I have installed the controller a month ago and I can confirm that the batteries have never been overcharged. In this small installation I do have more power then needed and therefore without the controller I'll be boiling the batteries on a daily basis.

The photo below is displaying the 12v Control box and next to it the charge controller.

The dump load has been enclosed in a box...

Trojan 6v T-105 Deep-Cycle Flooded

The 12v system batteries have been replaced with 2 x 6v Trojan Batteries rated 225 Amp-Hours at the 20-HR Rate. Details about these batteries can be found on the Trojan website or here 

The batteries have been installed in the battery box to 

1) Eliminate any accidental contact with the terminals. A short circuit on the terminals can easily promote a fire. If a metal object drops on the terminals, a huge current will pass through it. In a matter of seconds the metal object will get so hot that it would be impossible to remove, it may even weld itself to the terminal blocks. This huge current will cause a huge sudden discharge during which the batteries will get hot and may explode.

2) Deep cycle batteries tend to gas heavily during charging. This gas is highly explosive and a spark can easily ignite the gas causing the batteries to explode. The battery box which I have installed is well vented so this possibility is further reduced.

These batteries will be charged using 2 panels.

• 50w 12v panel
• 150w 12v panel from solartronics

thus a maximum of 17 amps charging can be reached during the day. A Schneider Xantrex C35 Charge Controller has been installed in 'Diversion Mode' to protect the batteries from overcharging.