Can I connect a shunt in between JK BMS and negative pole with short alu bar?
- Thread starter Enduro
- Start date
sunshine_eggo
Happy Breffast!
No. BAttery > BMS > Shunt
Yep, but that's not the question.
sunshine_eggo
Happy Breffast!
You sure?
What is the "negative pole" to you?
I interpret that as the negative pole of the battery, so you are asking if you can put a negative shunt between the battery and BMS. That answer is no.
JK14
New Member
Treating this like a wire gauge question: 20x2mm has a cross sectional area of 40mmSq which is close to 1 AWG (42.4).
Lets assume 100A running through it at 12V.
Such a short length will have minimal voltage drop - about 0.1%
Heat will also be reasonable at ~12degC or 20degF above ambient.
It will function much like a 3 AWG copper bar and should be fine.
I'd consider the max ampacity around 160-170A for that bar based on NEC chart 310.15(B)(17) in free air for ~1 AWG aluminum.
For example, 200A would generate ~50 degC or 85 degF above ambient which will be plenty hot to touch.
Lets assume 100A running through it at 12V.
Such a short length will have minimal voltage drop - about 0.1%
Heat will also be reasonable at ~12degC or 20degF above ambient.
It will function much like a 3 AWG copper bar and should be fine.
I'd consider the max ampacity around 160-170A for that bar based on NEC chart 310.15(B)(17) in free air for ~1 AWG aluminum.
For example, 200A would generate ~50 degC or 85 degF above ambient which will be plenty hot to touch.
sunshine_eggo
Happy Breffast!
running the numbers for myself...
20mm x 2mm = 40mm^2
Al is about 60% the conductivity of Cu.
.6 * 40mm^2 = 24mm^2
3awg is 26.7mm^2, so it's pretty close.
Personally, if you have more of the aluminum, I'd double it up.
Aggressively scuff both sides with scotchbrite or sandpaper to remove oxide. Apply NO-OX-ID A-special to all contact faces. I would do the prep and NO-OX to even a single bar installation.
Aluminum is a good conductor especially when you factor in the price of copper. However, it's prone to surface oxides that reduce conductivity. Corrosion prevention is key.
20mm x 2mm = 40mm^2
Al is about 60% the conductivity of Cu.
.6 * 40mm^2 = 24mm^2
3awg is 26.7mm^2, so it's pretty close.
Personally, if you have more of the aluminum, I'd double it up.
Aggressively scuff both sides with scotchbrite or sandpaper to remove oxide. Apply NO-OX-ID A-special to all contact faces. I would do the prep and NO-OX to even a single bar installation.
Aluminum is a good conductor especially when you factor in the price of copper. However, it's prone to surface oxides that reduce conductivity. Corrosion prevention is key.
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