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2014-159 HR in CT
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Discussion Starter · #21 ·
Good info, and I understand that delivering a product for customers needs some more stringent parameters.

My current thinking is that...

- when the juiceBOX is being battery 4, the most draw should be about 50A if the 4 batteries distribute the maximum fused 200A load evenly

- if I connect a 1000W inverter, load should be about 80A... might be the highest load I'd use.

- the cost of the name brand breaker is more than I spent on the whole JiuceBOX!

- I thought about an ANL fuse... have the parts already and it would fit well, but... I like the idea of using the breaker as an on/off switch too...

So, I may think about it a bit and decide about the Blue Sea/ Buss breaker... not sure that an 80A breaker (with it's built in time lag) wouldn't be OK for my application.

Hmmmmm.......
 

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Good info, and I understand that delivering a product for customers needs some more stringent parameters.

My current thinking is that...

- when the juiceBOX is being battery 4, the most draw should be about 50A if the 4 batteries distribute the maximum fused 200A load evenly

- if I connect a 1000W inverter, load should be about 80A... might be the highest load I'd use.

- the cost of the name brand breaker is more than I spent on the whole JiuceBOX!

- I thought about an ANL fuse... have the parts already and it would fit well, but... I like the idea of using the breaker as an on/off switch too...

So, I may think about it a bit and decide about the Blue Sea/ Buss breaker... not sure that an 80A breaker (with it's built in time lag) wouldn't be OK for my application.

Hmmmmm.......
I completely agree with using a breaker in that location and for the reasons that you noted. I use them for the exact same reasons.

Given that you already have the set up built, it is probably worth just using it for a while in it's intended use and see what happens.

Maybe there is a way to leave space for the other breaker type for if / when the existing one gives up.

Usually they fail "tripped" so it is more of an inconvenience than a real danger.

Just like a fuse, a thermal breaker is essentially a resistor so they will get warm during use - so slightly over sizing it rating wise isn't a big deal and probably a good thing.

Officially the rating is supposed to be lower than wire ampacity, but as a practical matter, what you are protecting against is a dead short. The internal battery BMS might trip before the breaker even if you run a lower amp rated breaker.

That is actually the other reason to use a breaker in that application. In most modern LiFe batteries, the internal BMS will trip from an overload, etc but not damage it. To reset the BMS, you have to isolate the battery (+) from external voltages / bus bar and a breaker is a very convenient way to do this without getting the tools out to swap a fuse in and out.

___

This is one of the reasons that I suggest 24 volt systems. One breaker shuts down and isolates 2 batteries instead of just 1.
 
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