This site uses cookies. Cookies are used for user guidance and web analytics and help to make this website better and more user-friendly. If you do not want a recording, you can disable it under Legal notice & privacy statement

Banner BATTERY KNOWLEDGE

BATTERY KNOWLEDGE

SERIES AND PARALLEL CONNECTIONS –

THAT'S THE DIFFERENCE

 

Interconnections between batteries have an effect on voltage or capacity and performance during cold start.

Serienschaltung

Series connection

Added voltages

 

During series connection (= series circuit) the voltages of the individual batteries are added together. Two 12V batteries must be connected in series in order to implement a 24V electrical system power supply.

 

Please note:

  • Both batteries must have the same type designation.
  • Both batteries must be around the same age.
  • Both batteries must display the same level of charge.
  • The connecting cables must have the sufficient dimensions and be kept as short as possible.
  • Always change both batteries!


If the above recommendations are not complied with, the voltage will be distributed accordingly in series connection due to different internal resistances of the individual batteries, resulting in an asymmetrical load during the charging and discharging phases.

If asymmetry cannot be avoided (due to different temperatures of the batteries or 12V partial loads), we recommend that you use the Charging Equalizer. This adjusts the charging voltage across the batteries so that they are even.

Please note: When checking the charging voltage in the vehicle, you must also check the individual voltage of each battery!

Parallelschaltung

Parallel connections

Added capacities and cold start currents

 

During parallel connection the capacities and cold start currents of the individual batteries are added together. 

 

Please note:

  • Both batteries must have the same type designation.
  • Both batteries must be around the same age.
  • Both batteries must display the same level of charge.
  • The connecting cables must have the sufficient dimensions and be kept as short as possible.
  • Always change both batteries!


If the above recommendations are not complied with, the current will be distributed accordingly due to different internal resistances of the individual batteries, resulting in an asymmetrical load during the charging and discharging phases.

 

In parallel connections, sometimes high compensation currents flow between the batteries. If possible, we recommend that you only use one battery with a larger capacity. 

Why always change both or all batteries? 

 

With increasing use of the batteries, the internal resistance changes. The older the battery, the higher the internal resistance. If you now connect an “old” battery to a “new” battery, then currents or voltages divide up differently and this causes asymmetrical loads. 

 

If the batteries are not charged or discharged, then very high compensation currents flow between the batteries during parallel connection. This means that the “new” battery tries to charge the “old” battery. (potential equalisation)