How to top balance offgrid with just BMS

time2roll

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Sorry, I forgot to mention I am going to run a 8s 24v setup. I'm not sure what you mean by "running to the top....etc."
No specific need to run anything to 3.650 (top). If all cells stay under 3.65v as the battery is run up to 27.6 you are good to go. The BMS or an active balancer can take it from there.

Yes if you do have a runner, the top cell can be bled down or the battery charging voltage can be reduced. Please post how it goes.
 

aklb43

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@aklb43 are your cells also matched and batched?
Being that they came from the reputable dealer on here that everyone seems to use, yes. I'm not sure if it would matter if they weren't matched though, being that I'd bring them all up 3.65v by placing loads on the cells that were climbing in voltage to fast to allow the other cells to catch up.
 

Just John

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Beginning to assemble my battery setup and know I need to top balance the cells for optimal life. What I have at the moment is:
4 Victron SmartSolar 100v/20a/48v CC
1 Victron SmartShunt 500a
2 Daly 48v/16s/300a Smart BMS w/Bluetooth
32 New/GradeA Eve 3.2v/304ah LifePo4 Cells
12 Trina 325w Panels

The intended battery configuration was to do a 16s for each BMS then parallel the 2 BMS to the bus blocks that the CC's are connected to.

Is it at all possible to properly top balance the cells with just the 2 BMS's? If so how?
Easiest and quickest would be to charge them up as a pack with an active balancer until you reach 3.65v per cell.

If these are matched cells from Amy, you likely don't need to worry. The two sets that I purchased from her were well-balanced to start.
 

aklb43

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Easiest and quickest would be to charge them up as a pack with an active balancer until you reach 3.65v per cell.

If these are matched cells from Amy, you likely don't need to worry. The two sets that I purchased from her were well-balanced to start.
Yes, they are from Amy. I think the overkill bms is a passive balancer. That should still work right?
 

Just John

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Yes, they are from Amy. I think the overkill bms is a passive balancer. That should still work right?
I use a JBD and it works quite well. Overkill is just a better tested and warranted JBD. If you didn't buy cells labeled as "bulk" from Amy, those matched cells are shipped from EVE at identical states of charge. Assemble a pack and charge them up, you'll be fine.
 

aklb43

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She didn’t say anything about “bulk”. They are coming from a Houston warehouse.
 

Just John

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She didn’t say anything about “bulk”. They are coming from a Houston warehouse.
Amy from Luyuan doesn't have a Houston warehouse. It must be another Amy than the one we have used since 2019.

 
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aklb43

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Amy from Luyuan doesn't have a Houston warehouse. It must be another Amy than the one we have used since 2019.

 
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