A little late to the table here,but I have a question. In the video, you show the fuses attached to the positive leads, yet in the diagram, they appear to be on the negative legs. At first, I was confused to the way you oriented your batteries, but figured out it was a way to reduce cables and length. (the crossover between batteries), but I am still perplexed to the fusing. should the fuses be determined by maximum draw from the inverter, or by maximum output of the battery bank? I have a bank of 4x12v to do a 2s2p for 24v 200ah using 150a fuses on each positive leg of the series connections. Am I over/under fused?
Basically max current from batteries is important in fusing the battery side. We want to protect against shortcuts from the inverter side or between battery banks. Max inverter current from low voltage DC side must be considered when we calculate battery requirements.
It is possible to connect four 12 v battery, in series and parallel for 24 v system - two from a brand and another two from other brand? Same chemistry(lifepo4)
@CuAgFe I want to make a 70kw system for my home no gird I am getting 6 12v 500ah, calculating it 1500ah for two sets of 3 12 @500. That would be about right, and I know I need to make 2 sets of 3 to get, but it is the purge r parts I have a problem with. The batteries can take 100a max charging, only have 800 watts of solar and a 60 dc to dc and 24v 80a mppt, and not trying to keep them up 100% of the time it more for weather and not being able to charge them is why so big. But I am having trouble with everything else. I have not done anything but research, but I still am trying to figure out the rest.
@@KENZIIE_lol We've been designing and selling LFP battery packs for more than 15 years, so I know all about series/parallel configurations. A 4 cell series string will still be unbalanced even if you connect that 4 cell string in parallel with another 4 cell string without an active balancer.
@@kickgas7171 Then you are the man for me. :) Q: I have 4 12V 200AH batteries in series. During discharge from my inverter, the cell connect to the + sides takes all the drain. In fact, it often falls to 117V, while the other 3 stat at 13V. So I was thinking of rearranging them into a 4P4S. You're saying this is not the best course?
You made a mistake The plus and the minus shouldn't be connected to the same side of bank but every one from a side and the other from the other side so current is more equal in all batteries
Basically you are right but if they have similar internal resistance it is not very big issue. I monitor them and they discharge in pretty same Way. My goal was to make wires as short as possible. Thanks for the comment. Regards
I hooked up my 4 battery bank now as you said with equal length cables everywhere. Did run it with unequal length like in this video for 1 year with 2 months hard use and rest of year idle without battery balancer. After 1 year they was still in balance when I got a battery balancer.
Ohhh thanks so much, I've had different voltages in the paralleled batteries for a while now and inverter charger shuts down over night.
We have a 12 volts system but if we hooke up 24 volts system, doesn’t it work?
I have the same set-up but put 100amp fuse on each pair of batteries. My inverter is 3000w so total amps is 125amps...62.5 amps from each 12v pair.
A little late to the table here,but I have a question. In the video, you show the fuses attached to the positive leads, yet in the diagram, they appear to be on the negative legs. At first, I was confused to the way you oriented your batteries, but figured out it was a way to reduce cables and length. (the crossover between batteries), but I am still perplexed to the fusing. should the fuses be determined by maximum draw from the inverter, or by maximum output of the battery bank? I have a bank of 4x12v to do a 2s2p for 24v 200ah using 150a fuses on each positive leg of the series connections. Am I over/under fused?
Basically max current from batteries is important in fusing the battery side. We want to protect against shortcuts from the inverter side or between battery banks. Max inverter current from low voltage DC side must be considered when we calculate battery requirements.
@AUizGOLD77 fuses protect the cable from getting hot from overloading or short. Size the fuse based on the maximum load the cable is rated for
Please more explain about fuse you put it between batteries?
I have 4 battery in series and parallel in 24 but my battery power 200Ah/12v
What type of inverter you have and type of battery chemistry?
@@CuAgFe off grid enrgy promax inverter
Battery flood
200Ah/12v
It is possible to connect four 12 v battery, in series and parallel for 24 v system - two from a brand and another two from other brand? Same chemistry(lifepo4)
how about their capacity ? If they are similar they should not be a problem. I assume every battery have it's own BMS ?
Sir Good day,😊
How to connect 4 batteries 100ah into 24v system 200ah capacity, thank you sir
This is exacly shown on this video (2s2p config)
Could I get help with my 24v system?
Sure, tell what you need
@CuAgFe I want to make a 70kw system for my home no gird I am getting 6 12v 500ah, calculating it 1500ah for two sets of 3 12 @500. That would be about right, and I know I need to make 2 sets of 3 to get, but it is the purge r parts I have a problem with. The batteries can take 100a max charging, only have 800 watts of solar and a 60 dc to dc and 24v 80a mppt, and not trying to keep them up 100% of the time it more for weather and not being able to charge them is why so big. But I am having trouble with everything else. I have not done anything but research, but I still am trying to figure out the rest.
@@jihlnabaat6329 What will be the system volatage (24V or 48V) form battery side?
@CuAgFe 24v I don't think 48v would work but never done it before
Without an active balancer, you will soon reduce the capacity of the entire pack.
cells/batteries in parallel auto-balance.
@@KENZIIE_lol Sure, but who wires 3.2 Volt cells in parallel to make a 3.2 volt pack?
@@kickgas7171 You can arrange the wiring so you get the best of both parallel and series. So that 4 cell 3.2 pack can be a 12V battery with parallel.
@@KENZIIE_lol We've been designing and selling LFP battery packs for more than 15 years, so I know all about series/parallel configurations. A 4 cell series string will still be unbalanced even if you connect that 4 cell string in parallel with another 4 cell string without an active balancer.
@@kickgas7171 Then you are the man for me. :)
Q: I have 4 12V 200AH batteries in series. During discharge from my inverter, the cell connect to the + sides takes all the drain. In fact, it often falls to 117V, while the other 3 stat at 13V.
So I was thinking of rearranging them into a 4P4S. You're saying this is not the best course?
You made a mistake
The plus and the minus shouldn't be connected to the same side of bank but every one from a side and the other from the other side so current is more equal in all batteries
Basically you are right but if they have similar internal resistance it is not very big issue. I monitor them and they discharge in pretty same Way. My goal was to make wires as short as possible. Thanks for the comment. Regards
I hooked up my 4 battery bank now as you said with equal length cables everywhere. Did run it with unequal length like in this video for 1 year with 2 months hard use and rest of year idle without battery balancer. After 1 year they was still in balance when I got a battery balancer.