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How many batteries can I add to a 6000 XP

Don't see why there would be a limit as long as they are 48v and have bms's for each battery. I have ~160 kwh's of batteries on my 3 6000 xp's in parallel.
Yeah, you’re right. These batteries are all 48 V exactly the same same brand Aolithium. I’m just wondering about communications.
 
Yeah, you’re right. These batteries are all 48 V exactly the same same brand Aolithium. I’m just wondering about communications.
I am using JK BMS's in all my batteries which are running in parallel with each other and communicating closed loop with the inverters. You can also have them open loop with the inverters as well though if you wanted. As long as each battery has a bms and knows when to cut off charging/discharging for each battery.
 
For those paralleling multiple batteries, I've observed that once we got past a 1:1 ratio of inverter to battery and winter set in, the batteries started drifting far apart once we couldn't regularly get to 100% SOC. We now have three 6000XPs and five PowerPro batteries. When we had just three batteries (the original plan), they stayed in almost perfect synchronization. With 5, I'm seeing up to about a 25% SOC variation. And because I read battery SOC through the inverters (not the best design, @EG4TechSolutionsTeam), I don't know this is happening unless I go to the mechanical room and physically look at the screens.

I don't know that this is too much of a problem overall, and with the recent addition of 4KW of additional panels (and longer days) I'm not overly concerned. But the additional batteries definitely caused a wider SOC variation, so keep that in mind folks. It makes me less eager to allow the overall bank to go much below 30%, as I fear at least one battery may be depleted.
 
I think you can see each battery SOC see @Gavin Stone video for details
For those paralleling multiple batteries, I've observed that once we got past a 1:1 ratio of inverter to battery and winter set in, the batteries started drifting far apart once we couldn't regularly get to 100% SOC. We now have three 6000XPs and five PowerPro batteries. When we had just three batteries (the original plan), they stayed in almost perfect synchronization. With 5, I'm seeing up to about a 25% SOC variation. And because I read battery SOC through the inverters (not the best design, @EG4TechSolutionsTeam), I don't know this is happening unless I go to the mechanical room and physically look at the screens.

I don't know that this is too much of a problem overall, and with the recent addition of 4KW of additional panels (and longer days) I'm not overly concerned. But the additional batteries definitely caused a wider SOC variation, so keep that in mind folks. It makes me less eager to allow the overall bank to go much below 30%, as I fear at least one battery may be depleted.
I think you actually can see it see @Gavin Stone video for details with his power pro batteries. here is the link to his video
 

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For those paralleling multiple batteries, I've observed that once we got past a 1:1 ratio of inverter to battery and winter set in, the batteries started drifting far apart once we couldn't regularly get to 100% SOC. We now have three 6000XPs and five PowerPro batteries. When we had just three batteries (the original plan), they stayed in almost perfect synchronization. With 5, I'm seeing up to about a 25% SOC variation. And because I read battery SOC through the inverters (not the best design, @EG4TechSolutionsTeam), I don't know this is happening unless I go to the mechanical room and physically look at the screens.

I don't know that this is too much of a problem overall, and with the recent addition of 4KW of additional panels (and longer days) I'm not overly concerned. But the additional batteries definitely caused a wider SOC variation, so keep that in mind folks. It makes me less eager to allow the overall bank to go much below 30%, as I fear at least one battery may be depleted.

Yeah storage is great, but you need enough solar to properly charge that storage regularly. Otherwise they’ll drift over time.
 
For those paralleling multiple batteries, I've observed that once we got past a 1:1 ratio of inverter to battery and winter set in, the batteries started drifting far apart once we couldn't regularly get to 100% SOC. We now have three 6000XPs and five PowerPro batteries. When we had just three batteries (the original plan), they stayed in almost perfect synchronization. With 5, I'm seeing up to about a 25% SOC variation. And because I read battery SOC through the inverters (not the best design, @EG4TechSolutionsTeam), I don't know this is happening unless I go to the mechanical room and physically look at the screens.

I don't know that this is too much of a problem overall, and with the recent addition of 4KW of additional panels (and longer days) I'm not overly concerned. But the additional batteries definitely caused a wider SOC variation, so keep that in mind folks. It makes me less eager to allow the overall bank to go much below 30%, as I fear at least one battery may be depleted.
Yes the more batteries you have the larger the load threshold is for each BMS to be able to 'see' the current draw.. The large format batteries solved some of the issue which is worse with the server rack form factor.

Basically each BMS can only see above about 0.5A so 25W per pack. So if you have 10 packs any load under 255W will not register and so on...

System shunt continues to be the best friend in this regard.. I should really get one but will have to look at how much power it consumes for the smart features.
 
For those paralleling multiple batteries, I've observed that once we got past a 1:1 ratio of inverter to battery and winter set in, the batteries started drifting far apart once we couldn't regularly get to 100% SOC. We now have three 6000XPs and five PowerPro batteries. When we had just three batteries (the original plan), they stayed in almost perfect synchronization. With 5, I'm seeing up to about a 25% SOC variation. And because I read battery SOC through the inverters (not the best design, @EG4TechSolutionsTeam), I don't know this is happening unless I go to the mechanical room and physically look at the screens.

I don't know that this is too much of a problem overall, and with the recent addition of 4KW of additional panels (and longer days) I'm not overly concerned. But the additional batteries definitely caused a wider SOC variation, so keep that in mind folks. It makes me less eager to allow the overall bank to go much below 30%, as I fear at least one battery may be depleted.
A string of 5 batteries in parallel with the load/charger connected diagonally will experience substantial battery current unbalance.
See: https://diysolarforum.com/threads/calculation-of-parallel-string-currents-addendum.94178/
 
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For those paralleling multiple batteries, I've observed that once we got past a 1:1 ratio of inverter to battery and winter set in, the batteries started drifting far apart once we couldn't regularly get to 100% SOC. We now have three 6000XPs and five PowerPro batteries. When we had just three batteries (the original plan), they stayed in almost perfect synchronization. With 5, I'm seeing up to about a 25% SOC variation. And because I read battery SOC through the inverters (not the best design, @EG4TechSolutionsTeam), I don't know this is happening unless I go to the mechanical room and physically look at the screens.

I don't know that this is too much of a problem overall, and with the recent addition of 4KW of additional panels (and longer days) I'm not overly concerned. But the additional batteries definitely caused a wider SOC variation, so keep that in mind folks. It makes me less eager to allow the overall bank to go much below 30%, as I fear at least one battery may be depleted.
It must be more of a problem with more cells in a 48v vs say just 12v with 4 cells. I'm pushing my 3rd winter with 8 parallel SOK 12v batts (20kwh total) with zero issues. I have gone on long stretches scraping the bottom of SOC. Never had a battery drop out yet and I check them often. Also, I have heard SOK is good on matching cells but that is what I have "heard" so...
 
I wonder how bad this is with the Ruixu 10-stack cabinet..
The chart shows how bad the unbalance becomes for 8 batteries compared to 5 batteries. Ten batteries will be just that much worse than eight for the total diagonal connection. Connecting more toward the middle would help a lot but I haven't done the math for that case so I can't say where best to make the connection. :(
 
I wonder how bad this is with the Ruixu 10-stack cabinet..

I'd like to see the inverter setup that can pull 100A out of 10 batteries at a time. Heck, even 50A, would be 500A, that's over 24kw of power... For a surge load, sure, but that's a ton of power for a continuous load.
 
It must be more of a problem with more cells in a 48v vs say just 12v with 4 cells. I'm pushing my 3rd winter with 8 parallel SOK 12v batts (20kwh total) with zero issues. I have gone on long stretches scraping the bottom of SOC. Never had a battery drop out yet and I check them often. Also, I have heard SOK is good on matching cells but that is what I have "heard" so...
Are you using the total diagonal connection to the 8 parallel batteries?
The effect of moving the load connection from total diagonal to a point more toward the middle is shown here for 5 batteries:
https://diysolarforum.com/threads/calculation-of-parallel-string-battery-currents.37937/post-488325

The chart here: https://diysolarforum.com/threads/c...l-string-currents-addendum.94178/post-1257802
shows the improvement that can be had for 8 batteries with the optimum load connection.

edit: It's possible to have 8 batteries hooked up with perfect balance like this:
https://diysolarforum.com/threads/c...l-string-currents-addendum.94178/post-1257802
 
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I'd like to see the inverter setup that can pull 100A out of 10 batteries at a time. Heck, even 50A, would be 500A, that's over 24kw of power... For a surge load, sure, but that's a ton of power for a continuous load.
The choice of 100A per battery is just a mathematical convenience. When a calculated current is not 100A but, say, 113A you can see in an instant that the error is 13%.
 
The choice of 100A per battery is just a mathematical convenience. When a calculated current is not 100A but, say, 113A you can see in an instant that the error is 13%.

Ok, so you chose 100A for math reasons, fine. Is it a linear scale, in how far apart they are, based on current draw? Aka, if I'm only drawing 20A from each battery, is it better for the balance?
 
Ok, so you chose 100A for math reasons, fine. Is it a linear scale, in how far apart they are, based on current draw? Aka, if I'm only drawing 20A from each battery, is it better for the balance?
Balance is not affected by how much draw except as second order effects.
It's linear. If you're drawing 20A per battery just divide the values in the chart by 5.

The values in the chart are calculated from the resistances in the stack; link resistance, battery IR. If those don't change, balance doesn't change.
 
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Balance is not affected by how much draw except as second order effects.
It's linear. If you're drawing 20A per battery just divide the values in the chart by 5

So the long and short of it is, does it really matter at the end of the day? Or are your batteries still going to age out before they have some capacity issues?
 

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