Tweet
Thats about as much voltage sag as a Fork Lift battery has at 35 amps @ 48 V.
-
-
That will limit the depth of discharge, especially when heavier loads come on.
A boost from a small LFP battery pack would help alleviate the problem and extend the range of the AHI pack. Would also help with efficiency, as AHI isn't as efficient with higher current draws.
The alternative is to run the generator more frequently.Comment
-
Since the Schneider Engineers were on site and set this system up, it's hard to for anyone to know what limits are programed into system.Comment
-
And that will initially show up when heavier loads come one even though the nominal battery pack voltage will be higher (due to voltage sag). This could inadvertently kick out the inverter, and thus one would encounter an annoying power outage, even though there is still plenty of capacity in the battery bank.
A boost from a small, highly efficient LFP battery pack could prevent that from happening, and extend the usable capacity of the AHI pack.
Somehow, I don't think manufacturers will be modifying all their inverters, at least not in the short term.Comment
-
At least one of their customers is reported to have whipped up a
hybrid system using the AHI Technology married to Marine Batteries.
However it sounds like a Direct Link set-up which makes it a
primitive hybrid. Nothing like what I propose.
One of my friends just fed Aquion Energy The Slave Bank idea
yesterday. I hear the guy was excited.
Problem: expense.
Became excited about the AHI deal years ago.
Now it's to the point of Look-see time.
Several key points have not been considered yet.
Bill Blake
Comment
-
That would be stupid and ignorant at the same time. To use a battery that cost twice as much as LFP, when LFP can run circles around AHI in every performance metric you can think of. LFP voltage does not sag to any significance until of a discharge rate of 3C or more, where AHI collapses to unusable with just a very small C/8 current. AHI is on the same ground as NiFe of unusable and impractical. You cannot tap the lower 40% or load it heavily not to mention extremely inefficient.MSEE, PEComment
-
I am not worried about the battery, but concerned that the inverter will drop off-line at a SOC much higher than I would find acceptable. I don't know if I am interpreting correctly, but if the OP is using 35% of the battery capacity daily, that wouldn't work for me even if I could use 100%. But I can't get near that.
As a point of note, while other many XW units are rated to go to 40V, the XW6848 that the OP has is rated only to 42V.Comment
-
Comment
-
AHI S10's were 1st Generation - S20's today are 2nd Gen.
Where that 540 Ah for 1st Gen. Aquion Energy Modules came from I don't know.
They had several different Modules all claiming 489 Ah using
S10 Battery Stacks for the first generation -
like we have been talking about.
The same size Modules today using S20 Stacks are 612 Ah
down to 30 Volts.
604 Ah down to 40 Volts.
Quite a percentage difference.
There are lots of spreads and number but anyway you cut it
if they are honorable and true this technology is on the move.
Aqueous Hybrid Ion .. Generation 3
is warming up in the bullpen for Later this year according to 'da boys'.
We will see.
old Bill BlakeComment
-
There's more to the cost of the battery than the upfront cost. It all will boil down to cycle life, and that's where the AHI batteries will very likely have the advantage. Do the math. AHI has a potential cycle life of 10, 000 cycles to an average depth of discharge of 25%. However, calendar life of both options remains to be seen.
Other fact is LFP battery prices are increasing. AHI prices are expected to drop.Comment
-
Unless the Schneider Engineers changed the firmware when they set the system up, we do know the were on site. XW-6048, Aquion Firmware ver 1.10. ? Of course we don't know that the hardware capability is. Midnight Solar has had a set of Aquion Batteries for over a year tweaking a controller for them.Comment
-
I don't know about the OP's exact location, but Honolulu gets 5.5 hours of sun on average in winter. Where I would build a system, only 1.75 hours average in winter.
The OP reports he hasn't used his generator at all, in I believe at least a month of use, in the heart of winter. And the deepest discharge is 50% This blew my mind. I don't know if you could find someone who could say the same in NY. I contacted a real estate salesman just two days ago who happens to be off-grid in the area I am considering. As I expected, he says he uses his generator on average every other day for about 3 hours with his FLA batteries. In summer, he has more power than he knows what to do with - typical story.
I can see how this system meets the needs of the OP very well. A huge advantage is the insolation, even if I have the number off by 50%. If I could go solar and not have to think about using a generator off-grid, I'd be thrilled. Right now, I'm looking at about $28K for an LFP system and gen backup. An AHI system maybe $45K. If I had unlimited space, which I do not, maybe for an additional $10K I could double the size of my array to boost the charge current at non-peak hours. At peak hours, I am already at the recommended peak charge current of the batteries. But I also have total shading at the margins (before 9:30, after 3:00).
I am new to this, but personally AHI is impractical for my application. Doesn't mean it isn't a valid technology. These two scenarios are at the extremes. Sunny Hawaii @ 21 deg N, and cloudy NY @ 42 deg N.
Just some thoughts I have as a read about this system, and drool a bit. I am interested in learning more about the OP's experience.Comment
-
Me too. It will be interesting to see at what point in the discharge path the battery drops below 42v and how the inverter handles the issue.
Seems kind of crazy for Aquion to advertise a very deep DOD battery yet a standard inverter will stop working way before you get to that discharge point.Comment
Comment