Aquion Energy batteries

[Sunking]

OK Amy here is my issue. Internal Resistance is way too high. Using the product sheet for the M100-L082 which is a 48 volt 540 AH battery we can determine Ri from the Voltage vs Capacity curve of 75 milli-ohms. I know to most folks that means nothing to them, but that is significant. For low voltage systems one of the design goals is to limit voltage sag at the battery post to 2% of less. Using a nominal voltage 48 volts and 540 AH capacity means you can only draw .96 volts / .075 ohms = 12.8 amps. On a 540 AH battery that is a miserable C/40 discharge. That is unusable. Basically means you got this huge battery that can only supply a 650 watt load.

Now take something like a Rolls 4CS17PS a 4 volt 540 AH battery. It has a Ri of 1.03 milliohms. It would take 12 of them in series to equal 48 volts giving you a total of lets just say 13 millohms. Using the same 2% design goal you can draw .96 volts / .013 ohms = 74 amps or roughly C/7 discharge current. Using the Rolls equivalent you can supply a 3500 watt load.

Now here is where it really gets ugly. If you can only discharge at a maximum of C/40 means you can only charge at a max of C/40. Again most folks are clueless what that means. But in essence makes it completely unusable because there is not enough Sun Hours in a day to recharge. Bare minimum winter sun hours for a FLA is 3 Sun hours before you exceed a C/8 charge current. For these batteries bare minimum is 16 sun hours. No place on the face of the planet gets 16 Sun Hours. In the lower 48 states Tuscon has the best in summer at 7 Sun Hours.

Sorry I do not see any application these batteries can be used for other than extremely low power application for telemetry in extremely remote locations where is cost is not a factor. Good grief if ever fully discharged would take two full days of commercial power to recharge. On solar more than a week on the equator, 2 or 3 weeks anywhere else. Heck even FLA batteries are a challenge with their relatively high Ri, but these are outrageous now that I see the real data. No wonder they hide it.

[Amy@altE]

What I'd like to see is information about the SEI layer in Aquion batteries - and if there even IS one. I suspect so, but perhaps it doesn't grow as fast as lithium ion batteries do.

Still the big point is that by reducing the effect of the naturally growing SEI layer, and by using common chemicals, it is a very interesting technology. All the "green" and salesmanship bore me to tears. Tell me more about the SEI layer with Aquion batteries, and I'm all ears.

I got a reply back from my contact at Aquion. He said" SEI growth is a phenomenon associated with organic electrolytes. We do not have an organic electrolyte, so there is no concern."

There are a couple of simultaneous post right now about the Aquions, but since I'm here, I'll answer questions from both. I'm not allowed to post links here, but I do have spec sheets for both the 51ah stack and 541ah module that may answer some questions. I'll attach to this post. Aquion M100-L082 Spec Sheet.pdf and Aquion S20-008F SpecSheet.pdf You can see on the Voltage vs Energy graph that at the lower amp draw, the voltage sag isn't as much as at the higher amperage, which is what they have been saying, the market is for lower wattage over a long period. If we consider 40V the lowest configurable low voltage cutoff for most 48V inverters, we can see that at 10A draw per stack, you can use about 800wh before hitting 40V, but at 6A, you can get about 1700wh before you cross that line. At 2A draw, you're up to about 2400wh before the inverter shuts off. Now this is per stack, so if you want to increase your power draw, you need to increase the number of stacks appropriately.

Keep in mind that only going down to 40V instead of 30V brings your depth of discharge from 100% to 80%, increasing the number of cycles from 3000 to 4000.

[Sunking]

1) Low voltage requirements. I checked the specs for the DC Voltage input range of the popular inverters we sell. They seem to be able to handle about 80% depth of discharge. I personally don't like to design any battery to its discharge limit anyways, so I would tend to oversize a little to extend the life of the system, regardless of the battery type. I'm comfortable with 80%, around 40V. All but the SMA can go at least to 40V.
a) Magnum PAE = 36V
b) Schneider XW+ = 40V
c) Outback GTFX = 40V
d) Outback Radian = 40V
e) SMA Sunny Island = 41V

OK I assume you are talking about 48 volt inverters right. Under load a FLA battery is completely exhausted at 1.75 vpc. So with 24 cells is 42 volts on a 48 volt battery system. See any problem with that?

High internal resistance. I believe that is only an issue with high current draws, which this battery is not designed for.

That is a show stopper. FLA battery systems are designed to handle a maximum C/8 load current because any higher is going to has voltage sag problems. Typical battery systems are designed for 5-day autonomy. Assuming you have the national average minimum sun hours in winter of 3 sun hours. Means your panel wattage is also going to equal C/8 charge current, which means panel wattage = inverter wattage. Well that alone is a huge problem for off grid folks because it means they have to oversize the battery to meet the Inverts maximum demands for those occasional loads like a Toaster, Microwave, ect... To get the same usable capacity and the ability to run an inverter at maximum capacity means a extremely over sized battery way beyond 5 day autonomy.

If I were going to spend that kind of money I want a battery that is compatible with all the equipment today and would look at using LFP.

[Amy@altE]

Again, I'm 2 days into my knowledge of the Aquions, so I'll answer questions as I get the answers.

1) Low voltage requirements. I checked the specs for the DC Voltage input range of the popular inverters we sell. They seem to be able to handle about 80% depth of discharge. I personally don't like to design any battery to its discharge limit anyways, so I would tend to oversize a little to extend the life of the system, regardless of the battery type. I'm comfortable with 80%, around 40V. All but the SMA can go at least to 40V.
a) Magnum PAE = 36V
b) Schneider XW+ = 40V
c) Outback GTFX = 40V
d) Outback Radian = 40V
e) SMA Sunny Island = 41V

2) High internal resistance. I believe that is only an issue with high current draws, which this battery is not designed for. If you have high current requirements, this is not the right battery for you. If you are trying to run your fridge, lights, laptop, and TV, which is the list most of my off-grid customers give me, I don't think voltage sag will be an issue. I have sent in a question to my tech contact there to confirm. I'm also checking on the surge of a well pump, although for off-gridders, we usually have them use a PV direct pump to a cistern, then a small DC pump on the battery bank for house pressurize.

3) Sizing/Pricing. Let's play with an off-grid cabin with 2.3kwh loads a day (pretty much the loads listed above), 3 days autonomy, 50F temp. Lead Acid math = 2300wh / .94 inverter efficiency / 50% DoD x 3 days x 1.19 temp deration / 48V = 364ah 48V. That's one string of 8 Trojan L16-RE-B 370ah 6V batteries for Flooded Lead Acid (FLA), or one string of Concorde PVX-4050HT 405ah 6V AGM batteries. I've got $2872 for the FLA and $5062 for the AGM. I can't do the math for you for the sizing of the Aquions, as I have a calculator tool they gave me, but I see needing between 3 and 4 stacks (depending on some variables) Let's say 4 stacks, 9792wh. That's $4620. So, more expensive than flooded, but less expensive than AGM. Cool.

I'll update posts as I get more details.

Amy

[Sunking]

Amy while it is true they can deliver 12 amps, you neglected to say how much the voltage would drop would be incurred. That is the problem, they have very high resistance making them unusable. Manufactures are not going to make a major overhaul of their equipment line so customers can use a single vendors batteries. The high Ri and queer operating voltages make them pretty much useless with all equipment. I was excited to until the details came out. Manufactures would have to make equipment specifically for the batteries. Just like NiFe batteries queer voltages, that is not likely to happen. IMHO they got a dud that will go thud on the market. They will not be getting my investment dollars.

You can give a price if you are smart about it and give it $/wh capacity. That will trick the uninformed into thinking they are cheaper to use.

[SunEagle]

I was concerned about giving pricing because I have been (rightly) warned not to advertise on this forum. I'm trying to find the balance between being helpful and informative and not breaking the rules. Right now I only have pricing for the stack, not the x12 module, but I'm sure there is a discount, not sure how much. I'll check. I will say the stack is under $1000, plus freight shipping. You can go to the altestore website for more details, and someone there can work up a shipping quote for you, as well as find out the module pricing.

That's ok. I don't want to get you into any trouble here.

I was just looking for a ballpark price to see how it compares to a similar sized FLA or AGM system with the understanding there are limitations with those battery chemistry.

[Amy@altE]

I was concerned about giving pricing because I have been (rightly) warned not to advertise on this forum. I'm trying to find the balance between being helpful and informative and not breaking the rules. Right now I only have pricing for the stack, not the x12 module, but I'm sure there is a discount, not sure how much. I'll check. I will say the stack is a little over $1000, plus freight shipping. You can go to the altestore website for more details, and someone there can work up a shipping quote for you, as well as find out the module pricing.

[SunEagle]

I'm very excited. I just met with Aquion yesterday. altE Store is taking orders for the S20 stack immediately! Due to pent up demand, there's currently a 6-8 week lead time, but they are available for order and will be shipping from Pennsylvania in January. We'll be able to ship anywhere in North America, including to freight forwarders to go to the islands and beyond.

Here's a bit more technical details from what I learned yesterday. I'll be getting more details shortly, but here's the Readers Digest version. Each S20 "stack", the smallest component sold, is 48V 51ah, or 2.4kwh. Their Module is 12 stacks in parallel for 25.5kwh. The old lead acid parallel restriction doesn't exist, you can parallel as many as you need to make as big of a system as needed, even up to the MWh. Each stack is limited to about 12A. So if you need to draw 6000W @ 120V, that's 50A. 50A/12A= 5 stacks needed (minimum). That's 51ah x 5 = 255ah, 48V, 12.2kwh. You wouldn't want to go smaller than that regardless of which battery type you use, so the 12A per stack restriction really isn't a big deal for most off-grid or battery back-up systems, which is its sweet spot. It is not intended for high draw, fast discharge applications.

As far as the charging side, same deal, if you have a 3000W solar array, 3000W / 48V = 62.5A / 12A limit = 5.2 stacks, round up to 6 stacks. 6 x 51ah x 48V = 14.7kwh battery bank. If we figure the panels can generate 3000W x 6 sun hours (summer) x .67 inefficencies = 12kwh generated. So a 14.7kwh battery bank that we discharge down to 80% DoD is 11.7kwh. Hmmm, that seems pretty well matched.

There is still the issue of most inverters will shut down at a higher voltage than the batteries can go down to. They are working with the major manufacturers to open up that voltage window. So meanwhile, 100% DoD isn't possible with an inverter system. They expect 3000 cycles at 100% DoD (30V), and 4000 cycles at 80% (40V). So, the disadvantage of not being able to drain the batteries completely actually extends the life by almost 3 years, turning it into a plus. You just need to size the system accordingly.

Amy

Amy

That is pretty good information but you neglected to include any pricing for a single stack or if there is a price discount by getting the 12 stack system.

[Amy@altE]

Aquions are now available!!!!!

I'm very excited. I just met with Aquion yesterday. altE Store is taking orders for the S20 stack immediately! Due to pent up demand, there's currently a 6-8 week lead time, but they are available for order and will be shipping from Pennsylvania in January. We'll be able to ship anywhere in North America, including to freight forwarders to go to the islands and beyond.

Here's a bit more technical details from what I learned yesterday. I'll be getting more details shortly, but here's the Readers Digest version. Each S20 "stack", the smallest component sold, is 48V 51ah, or 2.4kwh. Their Module is 12 stacks in parallel for 25.5kwh. The old lead acid parallel restriction doesn't exist, you can parallel as many as you need to make as big of a system as needed, even up to the MWh. Each stack is limited to about 12A. So if you need to draw 6000W @ 120V, that's 50A. 50A/12A= 5 stacks needed (minimum). That's 51ah x 5 = 255ah, 48V, 12.2kwh. You wouldn't want to go smaller than that regardless of which battery type you use, so the 12A per stack restriction really isn't a big deal for most off-grid or battery back-up systems, which is its sweet spot. It is not intended for high draw, fast discharge applications.

As far as the charging side, same deal, if you have a 3000W solar array, 3000W / 48V = 62.5A / 12A limit = 5.2 stacks, round up to 6 stacks. 6 x 51ah x 48V = 14.7kwh battery bank. If we figure the panels can generate 3000W x 6 sun hours (summer) x .67 inefficencies = 12kwh generated. So a 14.7kwh battery bank that we discharge down to 80% DoD is 11.7kwh. Hmmm, that seems pretty well matched.

There is still the issue of most inverters will shut down at a higher voltage than the batteries can go down to. They are working with the major manufacturers to open up that voltage window. So meanwhile, 100% DoD isn't possible with an inverter system. They expect 3000 cycles at 100% DoD (30V), and 4000 cycles at 80% (40V). So, the disadvantage of not being able to drain the batteries completely actually extends the life by almost 3 years, turning it into a plus. You just need to size the system accordingly.

Amy

[MikeSolar]

Still, even with the odd install system, I'd be willing to try them out. Don't know if they are available up here yet.

[Sunking]

FLA are problematic with solar having an upper charge/discharge limit of C/8. Anything less is a real problem. Many applications require C/4 to C/2. Once you drop below 4 Sun Hours, you got a problem of charge rates being too excessive.

[Amy@altE]

I wouldn't say good or bad, just different. The product line he has are designed for small systems, so 15A max per string is fine for what is is designed for. I'm sure the bigger lines have faster rates, but again, I haven't had any training on them yet, so it's all speculation on my end until I do.

Amy

[Sunking]

My coworker is using Aquions in his off-grid office system in Colorado. He has only had them a month or so, so no long term reports, but so far, they are working great. They are treated a bit differently than lead batteries, they come with #10 wire and connectors on them, so you can combine them in a combiner box, using a breaker on each string, and you can only charge and discharge at a fairly low rate. He's got them charging from a Schneider XW charge controller, and again, so far so good. I'm getting more training on them next month, really looking forward to getting more details.

Amy

That is not good.

[Amy@altE]

My coworker is using Aquions in his off-grid office system in Colorado. He has only had them a month or so, so no long term reports, but so far, they are working great. They are treated a bit differently than lead batteries, they come with #10 wire and connectors on them, so you can combine them in a combiner box, using a breaker on each string, and you can only charge and discharge at a fairly low rate. He's got them charging from a Schneider XW charge controller, and again, so far so good. I'm getting more training on them next month, really looking forward to getting more details.

Amy

[SunEagle]

The way they talk about them, it seems they want them to be used for off grid as well. I would be very interested in seeing how they work because the only other options, at the moment, if you want better longevity than a lead acid is a flow battery or NiFe, and both have their issues. Still, I don't think we have seen this much work into storage in decades.

Since the big push for Renewable energy there is a lot of people and organizations drilling down and looking for the ultimate energy storage device. What is being spent is probably the national budget for a small country. Finding a solution first will make someone a whole lot of money and maybe worth the risk of spending a lot to do so.

It is still too early to tell if anyone has found a low or moderate costing (and marketable) storage system although a lot of companies like to boast about what they are doing and how green it will be. That is pretty much advertisement to get more investors and money to continue the research.

Who knows. Maybe Aquion Energy will turn out to be a viable device. Successful breakthroughs happen but they are usually not the result driven by greed. Most times they happen by accident.