Being a nitpick but I don't think people are using the term "nominally" correctly here. Nominally would be the general name which in our case would be 48V. So it is 48V nominally. It doesn't change based in the chemistry since we are all dealing with 12V, 24V, or 48V nominal systems irregardless of chemistry used. All the balance of system components are based on those nominal voltages.
Why does a 48V100Ah LFP battery have a capacity of 5,120Wh instead of 4,800Wh?
- Thread starter Banjohn
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sunshine_eggo
Happy Breffast!
Uh-oh... you're about to get out-nitpicked...
I'll partially disagree with this. Take my inverter for example. 38-66V operating range for a "48V" system. What makes this system 48V nominal? Do other inverters adhere to this same range? No.
Per NEC article 100: Voltage, Nominal. A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 volts). (CMP-1)
It's a term of convenience, but when considering specific components, nominal voltage becomes more than a convenience. It becomes very important. The capacity of a 51.2V nominal LFP battery is higher than a 48V nominal LFP (or lead acid) battery of the same Ah capacity. The capacity of a 51.8V nominal 14S NMC battery of the same Ah is even higher. If I used "48V" for the purposes of computing capacity of 16S LFP or 14S NMC, I'd get the wrong answer.
If I'm buying a battery, I want to know the nominal voltage. In helping others diagnose their issues, sometimes, this is the only clue that we're dealing with 15S instead of 16S.
IMHO, being fast and loose with incorrect application of "nominal voltage" is why the OP was confused to start with.
It's indeed very confusing.Uh-oh... you're about to get out-nitpicked...
I'll partially disagree with this. Take my inverter for example. 38-66V operating range for a "48V" system. What makes this system 48V nominal? Do other inverters adhere to this same range? No.
Per NEC article 100: Voltage, Nominal. A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 volts). (CMP-1)
It's a term of convenience, but when considering specific components, nominal voltage becomes more than a convenience. It becomes very important. The capacity of a 51.2V nominal LFP battery is higher than a 48V nominal LFP (or lead acid) battery of the same Ah capacity. The capacity of a 51.8V nominal 14S NMC battery of the same Ah is even higher. If I used "48V" for the purposes of computing capacity of 16S LFP or 14S NMC, I'd get the wrong answer.
If I'm buying a battery, I want to know the nominal voltage. In helping others diagnose their issues, sometimes, this is the only clue that we're dealing with 15S instead of 16S.
IMHO, being fast and loose with incorrect application of "nominal voltage" is why the OP was confused to start with.
Portable power stations are much easier to understand.
Yeah, you can pretty much guarantee that anything a portable power station claims is misleading. All designed to hook the unwary.
wpns
Solar Joules are catch and release
Why? Have you measured the output with a DVM?
Sorry, I don't what a DVM is.
Portable power stations are why I want to know more about DIY systems.
If I visit this forum without the knowledge of the portable, I would have turned away.
There is a learning curve for someone like me.
Portable Power Stations -> DIY 48V Systems -> Residential ESS
wpns
Solar Joules are catch and release
Sorry, Digital Volt Meter.
exmarkretired
New Member
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That gets people also. Old (er) people use the term VOM. Having dinner with an Electrical engineer, elctrician and an old tv technician that can fix anything including the old tube stuff... It was suggested you can almost tell a persons age by how they refer to 110 VAC rms if they use 110 115 or 120....
We tend to use the term multi-meter in Europe more.
B-ManFX4
Solar Enthusiast
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Portable power stations all have the same confusing battery components inside them too...
ricardocello
Watching and Learning
If they are really old, they say 50 cycle or 60 cycle instead of Hz.
Yes, it's more suitable for entry-level DIYers like me.Portable power stations all have the same confusing battery components inside them too...
And really really old, they say piles instead of battery (unless they really have the piles).
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