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BMS Behavior in Parallel Battery Configuration

HRTKD

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+A = B = C-

The above battery wiring configuration is what we often see for lead acid batteries. It's simple, but not optimal. For a LiFePO4 battery, it's my theory that this is a bad configuration that could lead to undercharging.

If the BMS in battery A detects that the voltage has reached the limit it will disallow charging (High Voltage Disconnect). It can also do this if one of the cells within the battery exceeds the cell voltage limit. Once the BMS in battery A disallows the charge, it more or less gives the (middle) finger to batteries B and C, which may not have reached their full charge yet.

Is this theory correct?

Note: the above configuration is NOT how I have my two LiFePO4 batteries wired. Both my batteries have equal access to the charge source at the common bus bar. I'm asking for a friend that is new to LiFePO4.
 
There's still a parallel connection between the batteries, so if battery A goes HVD or LVD, the other two batteries are still active and now each sharing 1/2 of the current vs. 1/3.

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The lower 3 batteries are still in the circuit.
 
Thanks. I can see that I was wrong with my theory.

If this was a series connection, instead of parallel, would your answer be different?
 
Thanks. I can see that I was wrong with my theory.

If this was a series connection, instead of parallel, would your answer be different?

Very. Your theory would apply.

The other series batteries would get no incoming current due to the HVD battery's 0A allowed, but all batteries could still discharge provided they're separate port BMS.
 
I run 5 packs in parallel. the 2x 175's do reach 100% before the 3x 280's. As each 175' goes into "storage mode" when their Amp Input reduces to 1.5A +/- a bit the balance of available Amperage gets split between the 280's, as their Amps Taken decreases down to the combined End-Amps seen by Charge device. Once the entire bank is registering the endamps (in my case that's 14A) the charge switches into Float Mode and all the packs then level up together very nicely.

In my config, all packs are connected to the Common DC (Busbars) with equal-length wires.
Storage Mode is something that is built into the Chargery BMS and may not be available in other makes & models.
I am changing my entire BMS fleet to JKBMS B2A24S15P and I know these don't have a "storage" mode as such but I do not think this will be an issue in any case.

SERIES is another monster... 1 cuts off the other will get the full blast of what is available and if the BMS is not designed to handle a doubling of voltage & amperage, then you release the Magic Smoke.

BTW, I watch this "dance between packs" pretty much every day, so take it for what it's worth.
 
The other series batteries would get no incoming current due to the HVD battery's 0A allowed, but all batteries could still discharge provided they're separate port BMS.
SERIES is another monster... 1 cuts off the other will get the full blast of what is available and if the BMS is not designed to handle a doubling of voltage & amperage, then you release the Magic Smoke.

Two different answers. They can't both be right.
 
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