How to connect your batteries to make up a 24V or 48V system

15 CommentsThursday, 4 August 2016  |  Admin

How to connect your batteries to make up a 24V or 48V system

For larger systems with more than a couple of panels there are some advantages in running at a higher voltage:

  • DC cable losses are reduced
  • At higher voltage many charge controllers can run more panels

Most batteries are rated at 2V, 6V or 12V so you will need to connect them in series in order to reach the voltage you require.

Connecting batteries in series means connecting the (+) terminal of the first battery to the (-) terminal of the next battery. Each battery you connect in series increases the voltage of the battery bank.

Here are a few examples:

Two 12V batteries connected in series, the total voltage is 24V

Four 12V batteries connected in series, the total voltage is 48V

Four 6V batteries connected in series, the total voltage is 24V

What voltage should I run my system?

The voltage of your panel must be higher than the voltage of your battery bank. This is because most charge controllers are only able to step down the voltage from the panels to match the battery, and they can’t step it up.

  • Small panels (100W, 150W) are usually rated at 12V or 18V so in this case you would require a 12V battery bank.
  • Larger panels are often rated 24V or 30V (such as the 250W Ulica) and in this case you will do better with a 24V battery bank.
  • If you are installing several panels you can connect them in a string in order to achieve a higher voltage. Larger systems are best designed to run at 24V or 48V.

Advanced setup: connecting batteries in series and parallel

Suppose you have four 12V batteries but you want to put together a 24V battery bank. You could connect a pair of batteries in series, and then another pair of batteries in parallel.


Seyha
Sunday, 25 December 2016  |  13:25

Am have battery 12v two 6v two and 24v want to battery 48v


Percy
Thursday, 9 November 2017  |  1:36

easiest 2 diagram iv seen to describe it but still im stuck when i need to add more batteries.
i have 21 x 12v 55Ah deep cycle batteries.
how would i configure them for a 24v using 6500AH or 48v system at 1625AH.
if u could solve these problems i have i will paypal you 20.
:)


Admin
Thursday, 9 November 2017  |  10:46

Hi Percy,

Please can you email me your email address to info@newenergyco-op.co.uk and I hopefully be able to answer your question!

Best regards

Cliff


Shana
Tuesday, 14 November 2017  |  15:23

I have four 12v soler sels how much valtege battary i need


John
Tuesday, 20 February 2018  |  12:39

what will be th kva? and A/h of a 48v system if u built it with 24 2v 770a/h batteries


Admin
Tuesday, 20 February 2018  |  13:25

You would get a battery at 48Volts with 770AH but you would normally only run these at 50% depth of discharge if being discharged on a regular basis and if lead acid so this would be 335AH
You can discharge to a lower depth and the 2 volt cells are more resilient than 12 batteries. but this would shorted the life of the battery if done on a regular basis

The KVA figure would really depend on the inverter that you have driving the AC system as these are limited to the transformer size, however the 335AH is available whether you draw this in 5 minutes or 5 hours depending on the load.


Uli
Sunday, 8 April 2018  |  9:46

Hi there.
I need an advice i have 6 12v 130AH batteries which is the best way to connect them to my 24v 2500w inverter? And what size of cable and fuse do i need.

Thanks
Uli


Admin
Monday, 9 April 2018  |  11:05

Hi Uli,

You would need to connect 2 in series and 2 in parallel you will get a total storage of 260AH.
The Fuse would need to be 120A or possibly 130A depending on the load and the tolerance of the inverter.

Best regards


Uli
Monday, 9 April 2018  |  16:55

Hi there thanks with your advice the connections 2 in series and 2 in paralel make them 4 battery i have 6 in total so i just add them paralel and in series with the others?? And i have a 16mm rigid cable do you think is ok or its too small to connect the batteries and the inverter? And what size of fuse do i need to use between my 40A MPPT and the batteies?
Thanks again
Uli


Kapil Joshi
Thursday, 12 April 2018  |  6:06

How can I make connection of 24v from 9 v batteries


Luke A.
Saturday, 7 July 2018  |  17:46

Hi,

want to run my setup in 24Volts. I have 2 x 120Ah and 2 x 220 Ah Batteries.
How do I have to wire them ? 120Ah+220Ah in series and then both parallel ?

Luke


Praveen Kumar
Thursday, 27 September 2018  |  14:33

I have 60nos batteries each 12V 150Ah ,how to connect batteries for 48V with minimum power loss.


Peter Williams
Saturday, 29 September 2018  |  15:21

I have a disability scooter which is powered by 4 x12v x20ah batteries. How do set them up to make 48volts.


Admin
Tuesday, 2 October 2018  |  11:29

Hi Peter,

You will need to wire these up in Series to make up the voltage to 48v as per the diagram above.

MARKED
Four 12V batteries connected in series, the total voltage is 48V

Best Regards


Onesmus
Wednesday, 3 October 2018  |  18:27

what determines the size of charge controller??

 
 
 
 
 
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