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Two BMS Parallel Connection
#1
Is it possible to wired a two bms in parallel connections? for example, 50ampere 3S and connected to two 100P3S power wall. How to wire the connections if possible.
TIA...
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#2
With a Batrium, you can put as many longmons on one pack as you'd like, wiring them in parallel. The more longmons the more balancing current you will have. I can't speak for any other BMS since Batrium is the only one I have.
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#3
The issue with the cheaper BMS units, if your using them for protection is that if you have say 40A load and you have two BMS units in prallel that have FET's rated for 20A load when the low voltage level is reached and your pack is disconnected the timing between the two disconnects will not be the same and therefore you would end up with 40A trying to go through a 20A rated BMS. That is in a good case of just 2 units in parallel.

If it is just for increasing balancing current then yes, connect as many as you want in parallel. The same voltage tollerance levels will apply in that all the units will not operate/balance at exactly the same time (start and end voltage)..

With two 100p3s packs just have one BMS for each pack or connect the packs in parallel and connect the m to a single BMS.
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#4
Clarify here, I'm sure you mean 3s100p as 100p3s would be 100 sets of 3s connected in parallel. This would mean you would need at least 100 bms units. I think you mean 100 cells in parallel for a pack connected in 3s configuration, as this would yield a minimum of 1 bms that can handle a 3s configuration.
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#5
Stack them all up, 100 BMS units like slices of bread from a baker with an exceedingly long bread tin... oh, it's late, humour going sideways.... time for sleeeeep...
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#6
Hey Mike, what is the balance current for Batrium? I haven’t been able to find specs on their web page.
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#7
1.8A Max per Longmon From what I remember from other threads
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#8
I believe the longmons are rated for 1A if passively cooled and 2A if you have a fan cooling them.
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#9
Continues 1A and max 2A in general. And how couldnt you find it? I guess you didnt check the page for the longmon? https://www.batrium.com/products/longmon...0677864200


Good enough for rather huge packs! Recommended max 400-600A per 1A of continues balancing.
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#10
(06-25-2018, 11:37 AM)completelycharged Wrote: The issue with the cheaper BMS units, if your using them for protection is that if you have say 40A load and you have two BMS units in prallel that have FET's rated for 20A load when the low voltage level is reached and your pack is disconnected the timing between the two disconnects will not be the same and therefore you would end up with 40A trying to go through a 20A rated BMS. That is in a good case of just 2 units in parallel.
Wouldn't you just ensure the BMS's that you select are adequately rated to ensure that one single BMS can handle the maximum possible draw your system is designed to work with?

Sorry I know this is an old thread but thinking of doing a similar thing myself as I like the idea of the increased balancing capacity of a BMS for ever battery pack.
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