How to Get 48V out of a 12V Solar System

Cut the large insulated battery cable into short sections about 2 feet in length using the wire-stripping tool. You will need seven red sections and one black section. Save the remaining long cables for connecting the batteries to the charger unit.

Strip the insulation from both ends of each cable, exposing one inch of bare copper on each end.

Attach a battery terminal to both ends of each cable by pushing the exposed wire through the coupler on each terminal, then turning the two bolts clockwise until tight. Together, the bolts and coupler pinch the wire and lock it down.

Connect four of the deep-cycle batteries in series by attaching cables to the battery terminal posts. Press the cable terminals over the posts firmly and then tighten the square-headed bolt by turning the opposing nut clockwise with the pliers. Use the red colored cables to connect the battery's positive terminal to the next battery's negative terminal, linking them like alkaline batteries in a common flashlight. The battery bank will have one positive and one negative terminal still open.

Repeat Step 4 to create another battery bank with four batteries connected in series, for a total of eight batteries. You will now have four open battery terminals -- two positive and two negative.

Connect the remaining terminals in parallel, linking the positive terminal on one battery bank with the positive on the other bank. Use the red cables whenever they touch a positive post. Use the black cable to connect the last negative terminal post with the one on the other bank. You now have two 48-volt battery banks, boosted in amp hours by combining their output in parallel.

Strip both ends of each long cable to 1 inch, connecting one end to the negative post of one battery bank (black cable), and the other to the positive post (red cable) in the opposite bank. The open ends of each cable can be doubled to an existing battery terminal by loosening the coupler bolts and pushing the copper end through. Tighten the coupler over both cable ends.

Attach the open cable ends to the charger unit's corresponding terminals. The red cable goes to the unit's positive output and the black goes to the negative output. Most chargers will have screw-style connectors, like audio amplifiers, where the cable end is pushed into a catch and locked down with a screw on the front of the unit. Turn the screw clockwise until it is tight over the cable. Many chargers have LED lights that signal a bad connection (red or flashing) or a good connection (green).

Attach the solar panels with smaller gauge wire in the same fashion as the battery banks. Section and strip seven sections of red insulated wire and one section of black with the wire-stripping tool, then attach their output terminals to each other and the charger as though they were batteries -- eight in series (four panels by two), connected to another four in parallel. Each unit will have screw-type terminals similar to the charger unit. Tighten them clockwise over the exposed copper wire ends.

Connect the solar panel's positive and negative terminals (at opposite ends of the panel array, like the batteries) to the charger unit's input terminals. Lock down each exposed wire end by pressing it through the correct catch and turning the screw clockwise. The LED's on the charger unit (if present) should now all glow steady green, indicating that the banks are charging.