Charging 6 volt Batteries In Series With 12 Volt Charger

October 10, 2018 by Ben Leave a Comment

This is the second installment of our Simple Campervan Wiring Diagram Series. In this diagram, we look at using a 6V Battery Bank instead of a single 12V Battery. Below you will find a 6-volt battery bank wiring diagram for charging 6-volt batteries in series with 12-volt charger.

*Electrical work should only be done by a qualified service professional. These diagrams are here for use at your discretion*

The Sideways Movement Simple Campervan Wiring Diagram Series Part 2

Charging 6 Volt Batteries In Series With 12 Volt Charger

If you do or plan to do any type of off-grid camping (boondocking), then a 6V battery bank system is a superior choice over a single 12V battery. A 6V Battery Bank Charging System will give you added amp hours and increased life cycles. By charging 6-volt batteries in series with a 12-volt charger you allow your off-grid electrical the true capacity it needs.

Two 6 Volt Batteries In Series VS One 12 Volt

Life cycles

6 volt AGM Battery has more life cycles. (Discharging down do 80% depth of discharge.) 600-700 on average. A 12v AGM Battery, on average has only 150. Winner: 6V Battery Bank

Cost

The 6 Volt option must be used in groups of two. Because of this, the overall cost of a 6 Volt Battery Bank is much higher than the single 12 Volt option. Winner: 12V Single Battery

Size and Weight

The fact that you will need two batteries wired in series means a larger physical size and more weight than a single 12 Volt battery. You will need to take this into account when planning your build. Winner: 12V Single Battery

Dry Camping and Off-Grid Use

The 6 Volt AGM batteries have larger cells and because of this, they have a higher amp hour rating. A 6 Volt battery Bank I the best option if dry camping or “off the grid. Winner: 6V Battery Bank

Parts Required: (See the bottom of the post for some tips and pointers)

Tips and Pointers

Batteries; AGM type batteries are one of the best options for this situation. They don’t spill or produce dangerous gasses. The capacity of your battery will be dependent on the system load.
Fuses; Be sure to use fuses on all positive wires and install as close to the battery as possible.
VSR; The VSR or Voltage Sensing Relay is very important, this will automatically separate your house battery from the vehicles starting battery. This is needed so when the engine is off, your house systems do not draw power from the start battery.
Wire; The size of the wire you use is dependent on the system capacity. Although you could get away with using a smaller gauge wire, I recommend using the largest possible. This will allow for the quickest possible recharge once you start the engine. It will also prevent the possibility of burning wires.
Grounding; Although you can get away with just grounding the Auxiliary battery. I recommend running a neutral back to the start battery as well as grounding to the chassis at both batteries.