Tired of unnecessary waste of space in the camper and still having as much energy storage as possible on the road? Then switch your batteries together for more flexibility instead of buying a large, powerful utility battery!

Parallel or series connection

There are many cases where batteries in parallel vs series are used in life. We often need to make some connections to the battery to get the voltage we want. Before you decide on a switching method, you should rethink your intended use. This is because a parallel connection increases the capacitance at the same voltage, while a series connection multiplies the voltage and not the capacitance. Accordingly, you resort to in-series switching if, for example, you want to operate 24-volt devices. 24V can be achieved by connecting two pcs 12v lithium batteries in series.

That’s why parallel connection is worthwhile!

Do you have to cover a high energy demand on the road or do you want to live as self-sufficient as possible with the camper? Then use the parallel connection in your vehicle!

But these are not the only reasons. You can also make use of the following advantages with this circuit:

Cheaper initial investment: If you do not yet know how much capacity you actually need, you can test the power supply in advance by connecting two batteries in parallel.

Lower capacities and more flexible expansion: If you connect batteries with lower capacities, the expansion of performance becomes more flexible. For example, a 100Ah battery is always increased by 100Ah, while a 200Ah battery always multiplies by 200Ah.

Lower default risk: If a battery gives up the ghost, the circuit is passed over the still intact, second battery and you still receive power.

Longer service life due to even distribution of the load: The parallel connection distributes the load required by the current withdrawal to both batteries, so that a higher amount of electricity is available and a longer service life of the batteries is possible.

Attention: Not every battery can be combined!

As always, the choice of accumulators is of great importance here. Because the batteries should always be new and, above all, identical. This means that technology, capacitance and voltage must be the same. Therefore, for example, combine a 65Ah battery only with another 65Ah battery. Also these points should not be ignored:

  1. If possible, always change the batteries at the same time, otherwise a new battery could lose its service life due to the charging current to be loaded. The age of the batteries should not differ by more than 1 year.
  2. Place short connection paths between the batteries to prevent cable clutter and save space.
  3. To avoid a mutual discharge of the batteries, it is optimal to install a disconnecting relay. This disconnects the connection to the circuit at a stop or when the batteries are not charged.

How many batteries can I connect together?

We always recommend connecting a maximum of three batteries together. In the case of a circuit with three batteries, it is advisable to install an equalizer or charge equalizer. This has the background that not all cells within the batteries always have the same charge. Cells with lower values become overloaded and break. The “surviving” cells then try to compensate for this and are also defective more quickly. This minimizes the service life of the entire electrical circuit. If you use an equalizer, it regulates this process and delays a premature end of the batteries.

This is how interconnection works with parallel connection

The simple parallel connection

In general, there are two types of batteries to connect in parallel. As the name suggests, the simple parallel connection is easy to implement. The circuit starts at only one battery and is continued from there to the next. A connection from plus to plus and from minus to minus is established between the two utility batteries.

But would you rather cross-circuit than simply?

However, the cross-circuit has a decisive advantage over the simple switching method. Because if the batteries are switched crosswise, they act as one large battery, which has the positive consequence that the charging flow works better with this circuit. This allows even charging and discharging of the accumulators. Be sure to use a dedicated battery charger to charge the battery to avoid overcharging the battery with a mismatched charger.

This is how the cross circuit works!

If you apply this circuit, connect the plus cable to the positive terminal on battery 1 and continue to the positive terminal of battery 2. With the minus cable you proceed exactly the opposite. Run it to the negative pole of battery 2 and then to the negative pole of battery

The right charging method for batteries connected in parallel

Before you start charging, you should disconnect the batteries from the power access. This can be done by pulling the plug or by a circuit breaker. Above all, the number of chargers is important when charging suppliers connected in parallel. Remember: Each battery always receives its own charging port or charging port. Your own charger.


You should use the parallel connection of two batteries if you want to increase your capacity. The cross-circuit is particularly suitable for this, as it improves the charging flow of the lithium phosphate batteries and enables uniform charging and discharging. When interconnecting batteries, you should always pay attention to the same technology, capacity, voltage and the same age as possible.