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BMS's to Victron Multiplus

Hillbillybuddha

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I have 4 LiFePo4 12v 100ah batteries. I want to end up with 12v, 400ahs. Each battery has an external BMS. I want to charge these batteries through a Victron Multiplus. Would I hook up the BMS's to a bus bar, then the bus bar to a smart shunt, then to a Victron Lynx Power In, Victron Lynx Distributor. And hook up the multiplus to the Lynx Distributor?
 
Why not connect the batteries in parallel, in a balanced manner and then connect the charger to the batteries?

Your stated goal was to charge these batteries. All that other stuff is not necessary to charge the batteries.
 
Since the batteries are cells, I thought about connecting them in series and then connecting the four batteries in parallel. (They should give me 12v 400ah) and using one BMS. But I heard, if one cell goes bad, the whole battery is bad, so it's better to keep it a four separate batteries.

I would like to charge the batteries. That's true. But I'd really like to expand on my charging capabilities. I want to add solar and wind in the near future. I'd also like to be able to keep track of the batteries. How much power I'm using; how quickly they are charging.

Here's the system I designed (I still have to add fuses but I figured I'd do that when I figured out wire AWG.)

I bought everything on the list (and a few other things, like an or Orion DC to DC charger, a VE Bus Smart dongle from a guy who bought them for his boat but his boat caught fire before he could install them) and now I'm trying to install them on my boat.
Screenshot_20210802-231643_AndrOpen Office.jpgScreenshot_20210802-231643_AndrOpen Office.jpg
 
But I heard, if one cell goes bad, the whole battery is bad, so it's better to keep it a four separate batteries.
From what I have seen, cells don’t go bad like a light bulb. Worrying about that scenario is overblown.
With 4 distinct batteries in your battery bank, in parallel, one battery won’t drag down 3 batteries.

I do not have experience with a highly interconnected Victron setup so I will bow out. I love victron stuff though!!
 
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what exactly are the batteries in question (brand and model)?
 
what exactly are the batteries in question (brand and model)?
 
Ah, gotcha. There are pros and cons to each approach. If you parallel the cells first and then series (one battery, one BMS), you do "hide" cell-level issues ... but that's really rare once the battery is up and running and proven tested. You need a lot more bus bars to put this arrangement together - do you have enough?

If you go with the multiple battery approach, you need 4 BMS's obviously AND you need to fuse each battery (Class T ideally) so a failed battery can't cause the other batteries to try to dump into it.

As for the Victron equipment - it won't see the difference at all.

The diagram is accurate WRT the battery connections; just make sure you add a fuse to the positive side before the switch.
 
Sorry to hijack / revive this thread, but I have a similar mission and setup (48X 100Ah Fortune, 6X JBD BMS but not the Overkill model, 2X MPPT, SmartShunt, 2X Orion Cerbo GX) and am hitting a similar wall: How to efficiently (i.e. not going overboard in terms of complexity) yet safely connect the whole lot?

I don’t have a diagram but let’s see if I can bring across my intended setup like this:

Solar panels —> MPPTs —> DC Pos BusBar —> Charger Switch —> Breaker—> Multiplus —> Battery Switch —> ANL* fuse 200A / 32V (should be good for 400A @ 12V, no?) on positive and SmartShunt on negative —> BusBar(s) —> BMSs + batteries (all inter-fused with 200A fuses) and Cerbo GX.

And then also starter batteries connected to Multiplus with an Orion DC-DC and a dedicated Starter Battery / Alternator charging switch.

*Yes, I know it should ideally be Class-T, but they are very hard to find in Europe

There will always be a better setup, I know, but for now, will it work? I need to move my boat to a place where I can work on it a bit more (12 hour sail) and currently have zero power so need a quick and safe working setup ¯\_(ツ)_/¯
 
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