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60VDC Lifepo4 battery 20S 280AHr. I have two of these batteries, laser welded and already assembled in nice steel container with their BMS, Fan etc.

Jose Arias said:
Hello! This is my first post. I have two brand new in a box 60VDC Lifepo4 nominal batteries 20S 280AHr. They are very well build, with laser welded busbars and terminals, since they're already assembled in nice steel container with their BMS, Fan, ventilating channel, etc. I don't want to start cutting cells or modifying to make it 48VDC, instead I would like to buy an "All in One" that can work within these voltage range "62VDC-69VDC". The inverter I have now is 48Volts but it self protect at 60volts. Wonder if any of you guys encounter this problem before? or have a solution? Thanks!
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Are these the CATL modules that battery hookup if offering?
 
thesillym said:
I just received my modules a few days ago, but have not checked into the included bms. I bought a new bms to use with this pack assuming the included one is not usable.
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Got it! What's your plan to use your 20S module? Seems like the majority of the "All in Ones" available are made to stand around 60-66VDC not the 72VDC that those CATL are capable of @ full charge! I also noticed that those cell are glued to the bottom and in between the spacers so now I doubt my plan about pulling 4 cells and use it in my boat is going to work. Probably destroying will be the result.
 
Jose Arias said:
Hello! This is my first post. I have two brand new in a box 60VDC Lifepo4 nominal batteries 20S 280AHr. They are very well build, with laser welded busbars and terminals, since they're already assembled in nice steel container with their BMS, Fan, ventilating channel, etc. I don't want to start cutting cells or modifying to make it 48VDC, instead I would like to buy an "All in One" that can work within these voltage range "62VDC-69VDC". The inverter I have now is 48Volts but it self protect at 60volts. Wonder if any of you guys encounter this problem before? or have a solution? Thanks!
Click to expand...
What you want is going to clash with what exists.

Put me in the camp of changing the pack to be 16S cells and then all your issues go away.
 
Jose Arias said:
Got it! What's your plan to use your 20S module? Seems like the majority of the "All in Ones" available are made to stand around 60-66VDC not the 72VDC that those CATL are capable of @ full charge! I also noticed that those cell are glued to the bottom and in between the spacers so now I doubt my plan about pulling 4 cells and use it in my boat is going to work. Probably destroying will be the result.
Click to expand...
I plan on removing 4 cells from each module to make it a 48v pack. Then I’ll probably use the extra cells for my boat or something.
 
thesillym said:
I plan on removing 4 cells from each module to make it a 48v pack. Then I’ll probably use the extra cells for my boat or something.
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That was also my plan but, now after looking in more detail, "all the glue at the bottom, the cell's compression straps, the aluminun spacer also glue to cells, the steel armature, the laser welded busbars etc, plus the solid overall good build". I'm scare to damage it!. I'm thinking in probably to buy an $270 2880W step down DC-DC converter 72V to 48V to be able to use my 48 inverter even that this will reduce the total power. Have you found where to buy the connectors for the +; - terminals? I have seen so many but not the exact one that fit those!
 
Jose Arias said:
That was also my plan but, now after looking in more detail, "all the glue at the bottom, the cell's compression straps, the aluminun spacer also glue to cells, the steel armature, the laser welded busbars etc, plus the solid overall good build". I'm scare to damage it!. I'm thinking in probably to buy an $270 2880W step down DC-DC converter 72V to 48V to be able to use my 48 inverter even that this will reduce the total power. Have you found where to buy the connectors for the +; - terminals? I have seen so many but not the exact one that fit those!
Click to expand...
I have not found connectors for the + and - , but I can not get a reliable voltage reading from there anyways, so I assume they are attached to a relay somewhere. I’ll probably just tap into the bus bars.

Do you have a link for the dc-dc step down converter?
 
thesillym said:
I have not found connectors for the + and - , but I can not get a reliable voltage reading from there anyways, so I assume they are attached to a relay somewhere. I’ll probably just tap into the bus bars.

Do you have a link for the dc-dc step down converter?
Click to expand...
daygreen.com

72V to 48V 60A 2880W DC DC Step Down Converter Voltage Regulator w ACC Switch

Wide input voltage from 60 to 90V Work for appliances from 0AMP to 60AMP automatically 100% full rated power 100% full stable output current 100% burn-in test High-efficiency up to 97% Waterproof sealed Cooling by free air convection Surface mountable ACC Enable 3-year warranty Over-current...
daygreen.com daygreen.com
 
thesillym said:
I have not found connectors for the + and - , but I can not get a reliable voltage reading from there anyways, so I assume they are attached to a relay somewhere. I’ll probably just tap into the bus bars.

Do you have a link for the dc-dc step down converter?
Click to expand...
I believe the negative pole is connected straight using a flexible busbar to B-, and for the positive you to hook need the orange disconnect blade that comes in a separate bubble bag inside the crate.
 
thesillym said:
I have not found connectors for the + and - , but I can not get a reliable voltage reading from there anyways, so I assume they are attached to a relay somewhere. I’ll probably just tap into the bus bars.

Do you have a link for the dc-dc step down converter?
Click to expand...
I also tried connecting in series a bunch of 800Amps diodes that I bought long time ago for another project and for each one you add will lower .6-.7 volts without overheating much, but I order the converter to try it and see if is truly delivers the 60Amps as they claim. We'll see!
 
Jose Arias said:
daygreen.com

72V to 48V 60A 2880W DC DC Step Down Converter Voltage Regulator w ACC Switch

Wide input voltage from 60 to 90V Work for appliances from 0AMP to 60AMP automatically 100% full rated power 100% full stable output current 100% burn-in test High-efficiency up to 97% Waterproof sealed Cooling by free air convection Surface mountable ACC Enable 3-year warranty Over-current...
daygreen.com daygreen.com
Click to expand...
Is this converter bidirectional? I hope so as it will need increase the voltage to charge and lower the voltage to discharge.
 
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