n2aws
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Slight correction. Schneider recommends 440ah per XW Pro as the minimum, so it'd be 4 of those EG4 batteries. (and even then it's still technically undersized by 40ah)
Schneider XW and a single server rack battery
- Thread starter hwy17
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hwy17
Anti-Solar Enthusiast
I am, actually.
Unrelated firmware update failure, and comes with territory of a secondhand discontinued model. I am happier to be more experienced with xanbus now.
Goals are different. I don't have the money to charge past these problems but it's not the point for me anyway. The problems are the hobby, the cheaper and easier I can get my hands stuck on them the better.
I have an Orion JR2.
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hwy17
Anti-Solar Enthusiast
You know what it probably is, it's the overall tone of mine throughout the thread that expresses someone struggling and frustrated. That makes people want to help, and the easiest way to help would be to advise a different path that it less extremely fraught with problems.
I get it, that's on me. I do not always live up to the Zen of the art of motorcycle maintenance that I philosophically intend to. I try to stop in the frustration and remind myself "you choose to do this, you do it on purpose, and you'd be less happy if you didn't have these problems on your hands" but I am human and I will get lost in the thick of it over and over.
Just trust me that I am choosing to have these problems.
I get it, that's on me. I do not always live up to the Zen of the art of motorcycle maintenance that I philosophically intend to. I try to stop in the frustration and remind myself "you choose to do this, you do it on purpose, and you'd be less happy if you didn't have these problems on your hands" but I am human and I will get lost in the thick of it over and over.
Just trust me that I am choosing to have these problems.
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GXMnow
Solar Wizard
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Since you are doing this as a learning experiment...
I wonder if a moderate bank of super capacitors might help out what you are trying to do.
The maximum voltage of 16S LFP is 58.4 volts. Ultra Caps can typically charge to 2.7 volts. So you would need 22 of them in series.
There is a 2.7 volt 500 Farad super cap listed on Amazon
They are not exactly cheap, but that is a whole lot of surge current capability.
The data sheet on those caps show a peak current rating of 264.7 amps.
If you hunt around, I'll bet you can find a reasonable deal. I think these are the same caps in a 3 pack
Just $15.69 for 3 of them.
Or this board of 6, with balancing circuits.
It's $34.61, but you would need to wire 4 in series to handle the full operating voltage.
There are much better super and ultra caps available, but these seem like a decent cost to performance ratio. They are no 5,000 Farad Maxwells, but they are about 1/10 the price as well. But are they stiff enough to keep the XW happy? I have no idea. My XW-Pro pulls nearly double the average current on every half cycle peak of the AC waveform. Running at just 2,000 watts, the peaks are about 60 amps at 120 Hz.
If money was not an issue, 4 of these in series would do the job nicely
I wonder if a moderate bank of super capacitors might help out what you are trying to do.
The maximum voltage of 16S LFP is 58.4 volts. Ultra Caps can typically charge to 2.7 volts. So you would need 22 of them in series.
There is a 2.7 volt 500 Farad super cap listed on Amazon
They are not exactly cheap, but that is a whole lot of surge current capability.
The data sheet on those caps show a peak current rating of 264.7 amps.
If you hunt around, I'll bet you can find a reasonable deal. I think these are the same caps in a 3 pack
Just $15.69 for 3 of them.
Or this board of 6, with balancing circuits.
It's $34.61, but you would need to wire 4 in series to handle the full operating voltage.
There are much better super and ultra caps available, but these seem like a decent cost to performance ratio. They are no 5,000 Farad Maxwells, but they are about 1/10 the price as well. But are they stiff enough to keep the XW happy? I have no idea. My XW-Pro pulls nearly double the average current on every half cycle peak of the AC waveform. Running at just 2,000 watts, the peaks are about 60 amps at 120 Hz.
If money was not an issue, 4 of these in series would do the job nicely
hwy17
Anti-Solar Enthusiast
I did consider super caps!
But:
1. The price. A decent quality super cap set looked like it was going to cost $1200+ in which case I could just get more battery.
2. I think 100ah cells are in fact perfectly capable of handling this inrush, and that's how I settled on BMS solutions.
So yeah, super caps are super interesting, but I don't have the budget to get into them. Or if there's a cheaper DIY option I think I'd be better off learning BMS design than that for now.
But:
1. The price. A decent quality super cap set looked like it was going to cost $1200+ in which case I could just get more battery.
2. I think 100ah cells are in fact perfectly capable of handling this inrush, and that's how I settled on BMS solutions.
So yeah, super caps are super interesting, but I don't have the budget to get into them. Or if there's a cheaper DIY option I think I'd be better off learning BMS design than that for now.
BentleyJ
Solar Wizard
Keep in mind the Orion JR2 relay is rated at 175mA. This relatively low current handling capability must be considered when choosing the external contactor. It may be necessary to use the Orion to drive a low consumption SSR or intermediate relay rather then connect the contactor coil directly to the BMS
hwy17
Anti-Solar Enthusiast
Thank you. Yes, I'm gonna use an intermediate relay.
hwy17
Anti-Solar Enthusiast
Had our first power outage and I just gotta say I am so pleased with myself and this bypass solution. It gets the job done and we're running on battery, baby.
Downside is I found out 950w charging is actually not enough to keep up with our non HVAC usage, turns out I underestimated how our usage has grown.
Downside is I found out 950w charging is actually not enough to keep up with our non HVAC usage, turns out I underestimated how our usage has grown.
GXMnow
Solar Wizard
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That always seems to be the case. I always end up using more energy than I expect.
My rule of thumb on many things regarding power...
Whatever power you carefully calculate you need, DOUBLE IT
hwy17
Anti-Solar Enthusiast
v3.30 firmware changelog for the Lifepower4 contains:
"1. The number of discharge overcurrent locking is changed to 1 time to prevent the high-voltage battery from triggering overcurrent protection for many times when the battery with a large pressure difference is combined"
That sounds like it is meant to address tripping when batteries of different charge states are paralleled. But if overcurrent protection delay has been adjusted from 500ms to 1s that might help me too. I will test.
"1. The number of discharge overcurrent locking is changed to 1 time to prevent the high-voltage battery from triggering overcurrent protection for many times when the battery with a large pressure difference is combined"
That sounds like it is meant to address tripping when batteries of different charge states are paralleled. But if overcurrent protection delay has been adjusted from 500ms to 1s that might help me too. I will test.
hwy17
Anti-Solar Enthusiast
I think I've found the password to change my BMS parameters.
Question is am I triggering the .5-1.5s OC protection, or 300 "uS" short circuit protection. I think it's the short circuit as that has no corresponding alarm parameter and I get no alarm light or event.
I'm confused how short circuit is defined as microseconds when all other parameters are stored in the raw data as ms. I guess I will try changing short circuit from 300 to 1000 at first.
Question is am I triggering the .5-1.5s OC protection, or 300 "uS" short circuit protection. I think it's the short circuit as that has no corresponding alarm parameter and I get no alarm light or event.
I'm confused how short circuit is defined as microseconds when all other parameters are stored in the raw data as ms. I guess I will try changing short circuit from 300 to 1000 at first.
hwy17
Anti-Solar Enthusiast
It didn't work. I can change settings now but the microseconds setting for short circuit delay is wonky.
It defaults to 500, if you enter 2500 it will save 2500. If you enter 5000 it saves and then reads 2440. Any number over 2500 ends up reading as some random number below 2500 based on a pattern I can't discern. It almost seems like the value saves and then is read incorrectly like a bits mismatch. But in any case saving 2500 or 5000 it still won't handle the inrush current on a 2 ton inverter heat pump.
It defaults to 500, if you enter 2500 it will save 2500. If you enter 5000 it saves and then reads 2440. Any number over 2500 ends up reading as some random number below 2500 based on a pattern I can't discern. It almost seems like the value saves and then is read incorrectly like a bits mismatch. But in any case saving 2500 or 5000 it still won't handle the inrush current on a 2 ton inverter heat pump.
wheelman55
New Member
Shopman. Where do you get the 440ah number for XW+? What voltage is that for?
I installed an XW+ NA along with one Discover AES 48v 130 ah battery. I kept getting faults and shut downs.
I was an early adopter of the Discover AES 48v 130ah battery. At that time there was nothing in the docs stating how many of these batteries to use.
At some point the documentation added info stating a minimum of two of the AES batteries and a max of three AES batts.
I now have three of the AES batts for a total of 390ah. The system is quite happy.
hwy17
Anti-Solar Enthusiast
The 440ah minimum comes from the Schneider manual but it's based in the lead acid era, and arguably was formed around lead acid hazards - ripple current damage to smaller banks and maybe electrolyte boiling with smaller banks. Basically schneider was saying don't call us with your problems if you're not at least using L16's. A 440ah lead acid bank would've only been a 220ah usable capacity anyway by most people's guidelines.
SparkyGriswald
New Member
@GXMnow , I bought 400Ah worth of EG4 LFP, before I recently found out about the 440Ah minimum rec'd by Schnieder - I am curious - how did you set it up with the Insight or Gateway to charge for a 360Ah system? Can you change the "Battery Bank Capacity" to something lower than 440Ah or is there a hard lower limit of 440Ah in the charge settings. If there is a hard lower limit to the charge settings - how does that effect the 2% battery charging exit situation? Manual - "This settings impacts one of the possible battery charging exit conditions: when charge current dropsbelow 2% of the Battery Bank Capacity for 3 min" Thanks!
hwy17
Anti-Solar Enthusiast
I know for sure that setting goes down to 100, probably even down to 1.
GXMnow
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I entered 360 amp hours and it accepted it without setting any error and worked just fine.
My system had no issues transitioning to absorb mode, but the absorb did seem very short. But I think that has to do with my Li NMC batteries. Lead acid and LFP cells both will have the voltage fall back a bit when the charge current drops. So it has to hold more current to keep the voltage up. With my cells, it never took more than 15 minutes for the current to fall to where it dropped to "No Float". And since I added my DC charge controller, it stays in Absorb an even shorter time as the DC charging is actually still pushing the voltage up.
From what I gathered with my initial setup, the 440 amp hour minimum recommendation is based on lead acid batteries being able to handle the current surges with a small enough voltage dip. Lithium batteries are much stiffer and the voltage changes much less with a big current change.
My system had no issues transitioning to absorb mode, but the absorb did seem very short. But I think that has to do with my Li NMC batteries. Lead acid and LFP cells both will have the voltage fall back a bit when the charge current drops. So it has to hold more current to keep the voltage up. With my cells, it never took more than 15 minutes for the current to fall to where it dropped to "No Float". And since I added my DC charge controller, it stays in Absorb an even shorter time as the DC charging is actually still pushing the voltage up.
From what I gathered with my initial setup, the 440 amp hour minimum recommendation is based on lead acid batteries being able to handle the current surges with a small enough voltage dip. Lithium batteries are much stiffer and the voltage changes much less with a big current change.
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