Current best practice on life common port BMS wiring?

ericfx1984

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I have a pair of JBD 4s 200a common port BMS's... And a pair of 4s, 230ah, Eve cells

Plan to run a separate BMS on each 4S battery pack

However I'm seeing some conflicting information... Some folks suggest that the BMS should be allowed to handle charging the batteries.. other people seem to suggest that it is better to allow the solar charge controllers to be installed directly to the batteries therefore bypassing the BMS... I'm not really sure what the correct answer is and I was hoping somebody could clarify for me
 

sunshine_eggo

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I have a pair of JBD 4s 200a common port BMS's... And a pair of 4s, 230ah, Eve cells

Plan to run a separate BMS on each 4S battery pack

However I'm seeing some conflicting information... Some folks suggest that the BMS should be allowed to handle charging the batteries.. other people seem to suggest that it is better to allow the solar charge controllers to be installed directly to the batteries therefore bypassing the BMS... I'm not really sure what the correct answer is and I was hoping somebody could clarify for me

Depends. If you want to disable BMS protection for charging, you connect the charger directly to the cells. That way, if a cell has a problem, you can ensure you weed it out by destroying it with charging.

Alternatively, you can use the BMS to protect the cells from over-voltage by making all connections, charge/discharge, pass through the BMS.

In the event that the battery disconnects due to low voltage, charging directly at the battery terminals may be required to raise the voltage enough to reactivate the BMS.
 

ericfx1984

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Joined
Oct 10, 2021
Messages
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Depends. If you want to disable BMS protection for charging, you connect the charger directly to the cells. That way, if a cell has a problem, you can ensure you weed it out by destroying it with charging.

Alternatively, you can use the BMS to protect the cells from over-voltage by making all connections, charge/discharge, pass through the BMS.

In the event that the battery disconnects due to low voltage, charging directly at the battery terminals may be required to raise the voltage enough to reactivate the BMS.
Okay.. that makes sense thank you

So basically it sounds like it might be beneficial to have a bypass available for low voltage disconnect but providing everything is working correctly charging directly through the BMS makes the most sense
 

sunshine_eggo

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Okay.. that makes sense thank you

So basically it sounds like it might be beneficial to have a bypass available for low voltage disconnect but providing everything is working correctly charging directly through the BMS makes the most sense

Yes.
 
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