Fusing 48V battery bank

TallGrass

New Member
Joined
Mar 2, 2022
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8
Hi all. I have (3) 48V 100mah LiPo4 in a server rack ran in parallel hooked up to an all-in-one Off-grid Growatt 6kw 48V. I need advice on weather to put a 200a T class fuse close to the busbar on the battery rack and put a shunt between that fuse and the inverter (or) can I put a 175A DC circuit breaker in between the bus bar and the inverter to act as an overcurrent protection and a disconnect? Are my calculations correct? 6000/48 = 125 x 1.25= 156.25amps. Should I be fusing the positive and negative?

I also have a question about charging the batteries fully before connecting them together. The batteries have a built in 125a breaker. Can I connect the batteries in parallel and only flip on one battery at a time to charge fully via the solar array, then once all are charged turn them all on? Thanks in advance.
 
Last edited:

jberger

Solar Addict
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Jun 1, 2021
Messages
269
You would fuse on the positive, as close to the battery as possible to protect the wire.
The Neg Shunt would need to be prior to the neg bus bar to track all of the current used.
I charged mine separately, then connected them together and turned them on, didn't want to accidently screw it up so that approach made sense to me.
 

Bud Martin

Photon Sorcerer
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Aug 27, 2020
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3,208
Since the inverter has conversion loss, typical efficient of inverter is about 85% (see the spec of your inverter).
So (6000W/0.85)/48V = about 147A will be pulling from the batteries.
 

TallGrass

New Member
Joined
Mar 2, 2022
Messages
8
Since the inverter has conversion loss, typical efficient of inverter is about 85% (see the spec of your inverter).
So (6000W/0.85)/48V = about 147A will be pulling from the batteries.
Thank you guys. I sent you a DM Bud Martin
 

rmaddy

Full-time Solar-powered Trailer Life
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Nov 16, 2019
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You should read through the following thread:

 
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