is my connection correct ??

[zolar]

24v battery connection.png
I have 4x batteries each 12v and 200amh , I am making a system of 24v with a battery storage of 400amh , is my connection like what I draw, correct please ?

[thastinger]

yep, you're good, be sure to use the correct size connections and put some corrosion prevention on it, need some fuses on the output

[zolar]

hi, and thanks a lot thastinger,,
if my load about 400w , what is your advice about cable size .
also size of fuse between batteries and inverter. please

[thastinger]

hi, and thanks a lot thastinger,,
if my load about 400w , what is your advice about cable size .
also size of fuse between batteries and inverter. please

400W at 120VAC?
Cable sizing depends on the lenght of the conductor and the load, there is plenty of info on that on the web, if it is in conduit be sure to derate the conductors due to heat build up. About 1500W is all you could pull from that battery bank at a C10 rate so that would be 60 amps DC to the inverter. General rule of thumb is that the fuse would be 1.25 times that a 70-80 amp fuse should be ok.

But why wouldn't you just put all those batteries in series and go with a 48V system? Wires could be half the size, thus less expensive for the same output potential.

[zolar]

hi again thastinger ,,,
the 400w is at 220vac . and the distance to load 25m ,
and going on 24v system cuz my panels are 4x panels 24v of 320w each.
and I know I can make each 2x series but I want to try 24v system first , after I already tested 12v.
thanks a lot brother for all help you did. but 1 more question please , :
if you don't mind to tell which site I can see to calculate size of conductor needed comparing to specified distance , please

[SunEagle]

hi again thastinger ,,,
the 400w is at 220vac . and the distance to load 25m ,
and going on 24v system cuz my panels are 4x panels 24v of 320w each.
and I know I can make each 2x series but I want to try 24v system first , after I already tested 12v.
thanks a lot brother for all help you did. but 1 more question please , :
if you don't mind to tell which site I can see to calculate size of conductor needed comparing to specified distance , please

What is the watt rating of your inverter? Based on that wattage we can determine the size of the wire between the battery and it as well as the fuse rating.

The 3 conductor wire (hot, neutral and ground) for the 400watt 220vac load would probably need to be at least a #14 AWG or #12 AWG (I am not sure what mm that is) due to the 25 meter length.

[zolar]

thanks a lot suneagle ,,
the inverter is a 2kw pure sine wave , and and the I am using only neutral and hot conductors ( no ground ), and yes I would like to know tha size with mm2 cuz that's what we are using here, but I can manage comparing with AWG. ( I think 12AWG = 4mm2 ),
thanks again brother

[SunEagle]

thanks a lot suneagle ,,
the inverter is a 2kw pure sine wave , and and the I am using only neutral and hot conductors ( no ground ), and yes I would like to know tha size with mm2 cuz that's what we are using here, but I can manage comparing with AWG. ( I think 12AWG = 4mm2 ),
thanks again brother

You are correct. 12awg = 4mm2 wire size and a 14awg = 2.5mm2 wire.

Now with a 2000 watt 24V inverter you will need wire that can handle about 100 amps. That is probably a 2AWG copper wire or 35mm2.

[zolar]

oh !!!!
but the load only 400W?

[zolar]

and btw how you are sure of comparing AWG with mm2 ?
cuz I said that just with dealing with some cables from both mesurments,
if there is any schedule I can refer to please.
or if you can compare these AWG ( 2 ,4,6,8,10,12,14,16,18) with mm2 please.
thanks

[Mike90250]

here's a table

https://www.engineeringtoolbox.com/awg-wire-gauge-d_731.html

[SunEagle]

oh !!!!
but the load only 400W?

It really doesn't matter what the load is to size the wire. It depends on what the inverter can draw if the load is increased by design or by accident. 2000 watts at 24V calculates to 83.3 amps so the wire size should be the next size up which is 100amps. You can always use a smaller wire but you will need to reduce the fuse size so it protects the wire from too many amps.

I have seen people use a smaller wire but after replacing the fuse a couple of times they went to a large wire and corresponding fuse.

[zolar]

thanks mike for the link , and thanks suneagle for the info.
and thastinger , I found the inverter manual and I read it carefully and completely but didn't mention anything about grounding not even in safety points
I wonder if what I did by joining the negative ( - ) terminal of the battery to the main house grounding is a correct thing to prevent back voltage from inverter to battery.

[zolar]

suneagle,,,,, 1 more question, please
suppose the load is 2kw so the amps going will be 83.3 right?
so that amps in wich cable ?
the cable between batteries and inverter ? or also in cable between inverter and load ?
cuz after inverter the voltage will be 220v , so 2000 devide voltage will be less current ( 2000 / 220 = 9 ).
I hope you understand what I mean

[SunEagle]

suneagle,,,,, 1 more question, please
suppose the load is 2kw so the amps going will be 83.3 right?
so that amps in wich cable ?
the cable between batteries and inverter ? or also in cable between inverter and load ?
cuz after inverter the voltage will be 220v , so 2000 devide voltage will be less current ( 2000 / 220 = 9 ).
I hope you understand what I mean

83.3 amps would be in the cables between the 24VDC battery and inverter. If the load was 2kw then the amps in the cables between the inverter and load would be about 9 amps since the voltage is at 220VAC.