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Battery School

General Battery Care Procedures

General deep cycle battery care procedures

Reasons Why Batteries Fail

General Difference Between Gel and Wet Batteries

State of Charge and Sulfation

Connect Your Batteries for Optimum Efficiency

When batteries are connected in parallel, as in most R.V’s, the positive terminals are connected together and the negative terminals are connected together as shown below:

The main advantage of these parallel connections is that the total current delivering capacity is the sum of each battery’s current. The total current is equal to the sum of both batteries. The main disadvantage of this type of connection is that the total voltage available cannot exceed the voltage of the weakest battery.

Unfortunately, too often we see parallel connections that may be less efficient. For example, the diagram below shows the traditional way to connect the cables to a dual-battery pack.

The positive and negative cables are connected to the terminals on the same battery, battery #1. This puts more of the load on battery #1 for the cranking mode and it also gets a higher charging voltage when the dual-battery pack is being charged. Battery #2 doesn’t work as hard because it has extra resistance to overcome in the cables that connect it to Batt #1. Battery #1 doesn’t see that resistance so it is not affected. The cable and connection resistances reduce the efficiency of battery #2 when cranking or charging especially if corrosion develops. The figures shown below demonstrate more efficient ways to connect the battery cables to a dual and triple-battery pack.

Just A Little Corrosion Causes Big Voltage Drops

Don't Be Misled By Battery Ratings

Which Deep Cycle Battery Do I Choose?

Daily Amphere-Hour Consumption For Your RV

Safety Tips on Charging Batteries

Determining When A Battery is Fully Charged

Why Are My Batteries Discharged

What is the difference between series battery connections and parallel battery connections and how do they increase battery capacity and voltage?

Jump start procedures

Preparing your batteries for winter

Advantages and Disadvantages of using two 12 volt batteries connected in parallel or two 6 volt batteries connected in series.

Testing the battery