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Adding different AH/Non DIY LIFEPO4 Battery to my setup 280AH 24V.

brandonboosted

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I am currently putting together all my components for my solar backup setup. I currently have
2x 40A EPEVER Charge controllers
6x 320W 24V panels
280AH 8S (still in china)
250A Daly BMS
4000W Giandel PSW inverter

However I am getting antsy about getting this system up and my batteries will surely be another month or more. I want to buy a readily available 24V 100AH or 2x 12 100AH ready to go non diy lifepo4 batteries. I cant seem to find an answer or at least one I understand if it is possible to parellel one with my DIY 280H Lishen's. Any help or criticism is welcomed and appreciated, still very green to this all.
 
I am currently putting together all my components for my solar backup setup. I currently have
2x 40A EPEVER Charge controllers
6x 320W 24V panels
280AH 8S (still in china)
250A Daly BMS
4000W Giandel PSW inverter

However I am getting antsy about getting this system up and my batteries will surely be another month or more. I want to buy a readily available 24V 100AH or 2x 12 100AH ready to go non diy lifepo4 batteries. I cant seem to find an answer or at least one I understand if it is possible to parellel one with my DIY 280H Lishen's. Any help or criticism is welcomed and appreciated, still very green to this all.
LIFEP04 only you cannot parallel with NON LIFEP04
 
24V LFP + another 24V LFP is fine...
No Intermixing of chemistries in a battery bank, which is pretty obvious but had to be stated.

It's the Amp Hour capacity that is the bugger.
If you have a 24V/280AH and a 24V/100AH sitting side by side, it will work OK while both battery packs are within the Working Voltage Curve of 3.000-3.400 Vpc. BUT the moment the 100AH drops out, the 280 will attempt to Pack Balance and will transfer power over and thus sacrificing some capacity.

When Charging the 100AH will reach full first and likely cutoff and then the 280 will get the large part of the balance of charge while the 100AH will trickle in BUT the 100AH will be ticking on/off and can possibly have cells go into HVD Cutoff. *NOTE* Some Smart BMS' are capable of dealing better with this by place a full charged pack into "storage mode", not common.

The less AH Difference between packs the more balanced a "Bank" is, The sweet spot is less than 50AH difference IF you must have different sizes.

It is NOT Advisable to mix proper 24V/8S Packs with series'ed 12V/4S... such convolutions will ONLY result in issues. The KISS Rule Applied to Solar Setup & Configuration IS the rule that makes a successful installation. Every added complication is another potential weakness & point of failure.

Hope it helps, Good Luck
Steve
 
24V LFP + another 24V LFP is fine...
No Intermixing of chemistries in a battery bank, which is pretty obvious but had to be stated.

It's the Amp Hour capacity that is the bugger.
If you have a 24V/280AH and a 24V/100AH sitting side by side, it will work OK while both battery packs are within the Working Voltage Curve of 3.000-3.400 Vpc. BUT the moment the 100AH drops out, the 280 will attempt to Pack Balance and will transfer power over and thus sacrificing some capacity.

When Charging the 100AH will reach full first and likely cutoff and then the 280 will get the large part of the balance of charge while the 100AH will trickle in BUT the 100AH will be ticking on/off and can possibly have cells go into HVD Cutoff. *NOTE* Some Smart BMS' are capable of dealing better with this by place a full charged pack into "storage mode", not common.

The less AH Difference between packs the more balanced a "Bank" is, The sweet spot is less than 50AH difference IF you must have different sizes.

It is NOT Advisable to mix proper 24V/8S Packs with series'ed 12V/4S... such convolutions will ONLY result in issues. The KISS Rule Applied to Solar Setup & Configuration IS the rule that makes a successful installation. Every added complication is another potential weakness & point of failure.

Hope it helps, Good Luck
Steve
lead and LifePO4 are comparable https://diysolarforum.com/threads/p...-agm-batteries-in-the-same-battery-bank.5078/
 
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