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what bms to use ?

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(@sid-genetry-solar)
Member Admin
Joined: 4 years ago
Posts: 2883
 

I've only got ~12kwh of batteries so you're well ahead 😉.  At some point I would like to double that to 24kwh--but personally don't see any real reason to go further than that.


   
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(@notmario)
Reputable Member
Joined: 3 years ago
Posts: 314
 

40kwh of LiFePO4... wow.
I got 10kwh. Eventually i'd like 30kwh... basically 72 hours of normal power use...

I did now know you could use any [basically] AC breaker for 24v... I've been using fuses instead. (never blown one, thankfully...)
A bit weird... would one use a double-pole breaker? Or single pole on positive?

Now i see some cleanup in my future...


   
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(@sid-genetry-solar)
Member Admin
Joined: 4 years ago
Posts: 2883
 
Posted by: @notmario
I did now know you could use any [basically] AC breaker for 24v... I've been using fuses instead. (never blown one, thankfully...) A bit weird... would one use a double-pole breaker? Or single pole on positive?

Whatever works.  Issue with higher DC voltages is the arc--which if the breaker isn't specifically designed to quench said arc, the breaker will literally start a fire when you trip it or turn it off.  But more often than not, an AC-rated breakers will have a 32vDC rating (when listed).  It could be safe to assume that an AC-rated breaker with no DC rating would also be safe for 32vDC.

You could use a double-pole breaker and double it up for double the amperage rating...maybe? 

I don't see any benefits to disconnecting DC negative honestly.  Risks of disconnecting DC negative would include "floating" equipment...or the worst being alternate unexpected ground paths (like RS-232 or USB cables) that aren't rated to carry significant current.  If one of those got blasted with power due to an open ground, you'd have fried cables and blown electronics very quickly!


   
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