Inverter and Battery Question

[GoneWithTheWindows]

Hi All,

I have a question with regards to my inverter and battery setup.

Currently, I have a 1200Watt Mecer Inverter and 2 x 105AH Deep cell batteries.

I am wanting to add a 3rd battery, will I need to go up to a 2400Watt Inverter or doesn't that matter?

Apologies I know next to nothing about these things.

Please ELI5 it for me

Thanks in advance!

 

[Sinbad]

Is your inverter a 12V or 24V model? Ie, batteries in parallel or series?

 

[Gtx Gaming]

No need to go up in watts, you can connect up in way you have 300ah in total.

Not sure if it is serial or parallel, cant remember which one now.

 

[Tabac]

Morning. Is it that box on wheels setup ? Anycase, i have the same system. Adding batteries only makes the system last longer when power is off. So you can use the same Inverter.

 

[GoneWithTheWindows]

Is your inverter a 12V or 24V model? Ie, batteries in parallel or series?

The inverter is 12V, batteries are in series.

 

[Sinbad]

No need to go up in watts, you can connect up in way you have 300ah in total.

Not sure if it is serial or parallel, cant remember which one now.

If it's in series you'll need 2 new batteries connected in parallel with the existing ones. If it's parallel you can just add one at a time in parallel.

 

[Sinbad]

The inverter is 12V, batteries are in series.

If the batteries are in series it is not 12v unless you have 6v batteries.

 

[GoneWithTheWindows]

Morning. Is it that box on wheels setup ? Anycase, i have the same system. Adding batteries only makes the system last longer when power is off. So you can use the same Inverter.

Nah Just custom-built it. Mine is in a big black plastic thing from builders, has space for 2 more batteries

 

[Tabac]

If the batteries are in series it is not 12v unless you have 6v batteries.

Mine is 24v. 2 x 12v batteries in paralel i suppose. So how would i connect extra batteries ?

 

[GoneWithTheWindows]

If the batteries are in series it is not 12v unless you have 6v batteries.

Hmmm, ok I might be wrong then, it is in whichever config extends run time, not power output?
I am not kidding when I say I am very bad with this stuff.

 

[RedViking]

Just add a 3rd battery all in parallel if it is 12V. Will take a bit longer to charge (think it has 10A charger).

If it is 24V you must connect in series and add two batteries at a time.

 

[Sinbad]

Hmmm, ok I might be wrong then, it is in whichever config extends run time, not power output?
I am not kidding when I say I am very bad with this stuff.

Both would extend run time. Check your inverter specs.

 

[The_Ogre]

Mine is 24v. 2 x 12v batteries in paralel i suppose. So how would i connect extra batteries ?

That's in series, not in parallel

 

[Tabac]

Just add a 3rd battery all in series if it is 12V. Will take a bit longer to charge (think it has 10A charger).

If it is 24V you must connect in parallel and add two batteries at a time.

Is this series or parallel ? Fck yes .... i'm stupid with this.

 

[Tabac]

That's in series, not in parallel

Thanks. You're right. So i'll have to add 2 x batteries at a time ?

 

[RedViking]

Also OP you probably have a 1200VA which is 720W.

 

[Sinbad]

Just add a 3rd battery all in series if it is 12V. Will take a bit longer to charge (think it has 10A charger).

If it is 24V you must connect in parallel and add two batteries at a time.

No!
Wrong completely.

 

[GoneWithTheWindows]

Also OP you probably have a 1200VA which is 720W.

You are right...
Does that change anything with regards to adding a 3rd battery?
Another dumb question, if I buy the bigger inverter 2400va will it have any impact on run time?
I am guessing not, though.

@RedViking from your review of that inverter -



So confused, does that mean a bigger inverter does mean longer run times.

 

[RedViking]

No!
Wrong completely.

Dammit.

12V you will connect parallel.

24V you will connect in series as you will double the voltage of the two 12V batteries.

 

[RedViking]

View attachment 754496

Is this series or parallel ? Fck yes .... i'm stupid with this.

I edited my post. 12V is parallel. 24V is series.