Aquion Energy up and coming battery....opinions please

[donald]

Aloha Bill,

.......lucky for us since we do have a EU7000Si but Auto-start will not be available till this spring .................

I'm curious how are you managing fuel on a generator you don't use? I manage my fuel by putting it in the car every six months or so. But you probably have a fairly large amount stored? When I buy generator gas I do purchase the best available, and treat it with sta-bil.

[OffGridHawaiian]

Has anyone heard how these badboys do just sitting ?

Since people are saying these AHI wonders of the Western World
might hang around for decades when being 'babied' and
Sunking says they Likes being charged cool and slow -
who knows.

If the electrolyte also holds up near forever
and they don't suck replacement electrolyte water like some fool -
these units might make good 'Slave Banks' to eliminate generators
(for the most part) someday.

We are still dollars per gallon away from that conversation
and 'The Theory of Batterytivity'.

Bill Blake

Aloha Bill,

We are using a bank 24 S10's and so far we haven't had to use any generator (lucky for us since we do have a EU7000Si but Auto-start will not be available till this spring according to the tech at Honda) We do live in Hawaii so I guess that helps.

Here's how they're doing.

Conext22615Batt.jpgConext22615load.jpgConext22615PVAC.jpg

[Sunking]

http://gigaom.com/2014/07/20/behind-...solar-storage/

Interesting read about use in offgrid solar

That story is full of holes if you know about batteries.

To start by claiming Lead Acid are low density which is true of about 40 to 50 wh/Kg. So what? Aquion batteries are much lower density of 20 to 30 wh/Kg. Not something they want to brag about and is a big negative.

Next they claim their price per Kwh of $500 which is the same oas Lead Acid is a huge lie. A top of the line Rolls 5000 series battery has greater cycle life at 220 per Kwh. Again something they do not want to brag about, so they lied. LFP can outperform Aquion in every technical category at $300 to $360 per Kwh.

If you know the facts, Aquion has nothing to offer.

[nat1971a]

http://gigaom.com/2014/07/20/behind-the-scenes-of-aquion-energys-battery-factory-the-future-of-solar-storage/

Interesting read about use in offgrid solar

[northerner]

One would hope so. The current out versus current in ratio is called the Coulombic efficiency (after the unit of charge, the Coulomb).
But often the sales literature or even the specifications do not make it clear which efficiency is being quoted.

I see other sites mentioning that the AHI battery has a round trip energy efficiency of 85%. Would really be great to get some feedback from actual users?

[Living Large]

One would hope so. The current out versus current in ratio is called the Coulombic efficiency (after the unit of charge, the Coulomb).
But often the sales literature or even the specifications do not make it clear which efficiency is being quoted.

For batteries with high internal resistance (higher in FLA than in AGM, for example) the difference between charging voltage and discharge voltage for the same current is significant.
Mike can tell you about the voltage difference for his NiFe batteries, for example.

I believe the equivalent to what Dereck stated above in regards to my focus on Ah, and not Wh - I was ignoring inefficiencies with high Ri. According to Dereck's estimate, and my calculations, the Aquion battery has about 6 times the Ri of the Rolls FLA battery he cited. I don't believe I have seen Ri specified by Aquion in any of its literature.

On another board, there is a participant who has been testing Aquion stacks for them, and I believe he mentioned that Aquion sent him a later version that was performing better in some regard. I may be wrong, but I believe he stated the newer stack has a lower Ri. I'll try to find that post.

[inetdog]

One would hope so. The current out versus current in ratio is called the Coulombic efficiency (after the unit of charge, the Coulomb).
But often the sales literature or even the specifications do not make it clear which efficiency is being quoted.

For batteries with high internal resistance (higher in FLA than in AGM, for example) the difference between charging voltage and discharge voltage for the same current is significant.
Mike can tell you about the voltage difference for his NiFe batteries, for example.

[northerner]

LFP is essentially 100% efficient in terms of amp hours but do not be fooled because amp hours do not mean squat. Listen to this and wrap your head around it because it is important to understand.

What is 1 AH on AHI being charged up at 60 volts? 60 watt hours right? What is 1 AH at discharge when below charge voltage say at 48 volts or all the down toward 80% DOD of 33 volts? Could it be 33 to 48 watt hours? That round trip efficient Northern is speaking about is gobbely gupe Marketers use to make their crappy product sound good. AH efficiency don't mean squat. Even if AH efficiency were 100% like LFP, watt hour efficiency is not because charge voltage is higher than discharge voltages. Good thing about LFP is the flat charge/discharge curve makes the efficiency as high as you possible can get say compared to FLA or AHI.

To consider efficiency, wouldn't one compare voltage levels for charge and discharge at a particular battery state of charge. For example if your charging at 1 amp at 50 volts, the difference in voltage would be not as significant if you now started discharging with 1 amp. The voltage for charge and discharge both go up as battery state of charge goes higher and vice versa.

I would think the efficiency of the AHI batteries that Aquion posts is referring to energy efficiency and not just AH???

[northerner]

You are certainly a cheer leader for them! Do you work for their sales department or do you just make a habit of believing all the sales BS companies put out?

Russ, I don't work for their sales department. I'm hoping it's not sales BS, as I myself am looking to reduce battery expense. I'm sure others are as well.

[russ]

There is nothing else out there that can even come close to competing with this! And the price is expected to continue dropping.

You are certainly a cheer leader for them! Do you work for their sales department or do you just make a habit of believing all the sales BS companies put out?

[northerner]

I do not agree that all things considered, AHI is "the most economical option". For my system, I need to upgrade everything just to charge them, and charging takes a long time. This all costs $$$. That is the downside to the discharge/charge characteristic that you argue lends itself to solar. As for absolute cost, for me there is a risk cost with AHI at this point. How do you put a price on that? You have people here still calling it vaporware.

As for cell balancing of LFP - that pretty much takes care of itself after initial balancing. Shunting will keep the cells in balance. It adds some complexity, small cost, and wastes a very small amount of energy.

An intangible is size and weight. The LFP is something like a pickup truck compared with AHI being a tractor trailer, IMO. Literally and figuratively. I like being able to move stuff around without a lot of effort.

The only difference in charging will be in the difference of efficiency between AHI and LFP, which on average should only be about 10%. Actually having a larger bank, which is likely for a more efficiently designed AHI system, will reduce the amount of generator run time, allowing you to get through longer periods of cloudy weather. A properly designed solar system in conjunction with storage, will allow you to minimize generator run time.

The biggest expense with an off grid system by far, is batteries. They have a cycle life and need changing periodically. So savings here will have the biggest impact. Current price for LFP is over 20 cents per kwh, factoring in cycle life. Current price for AHI is 16 cents per kwh. This is more than a 10% savings, so is the better value. The big plus is if AHI drops down in price to 70% of what it is now, as expected by year's end, that would put it at just over 11 cents per kwh. There is nothing else out there that can even come close to competing with this! And the price is expected to continue dropping.

[Living Large]

Bottom line is overall cost, ie price per kwh over the batteries rated cycle life. If LFP's came down in price and the issues with cell balancing worked out, I would consider them. At this point, the AHI batteries are likely the most economical option (providing they put out as advertised), and price is expected to drop.

I do not agree that all things considered, AHI is "the most economical option". For my system, I need to upgrade everything just to charge them, and charging takes a long time. This all costs $$$. That is the downside to the discharge/charge characteristic that you argue lends itself to solar. As for absolute cost, for me there is a risk cost with AHI at this point. How do you put a price on that? You have people here still calling it vaporware.

As for cell balancing of LFP - that pretty much takes care of itself after initial balancing. Shunting will keep the cells in balance. It adds some complexity, small cost, and wastes a very small amount of energy.

An intangible is size and weight. The LFP is something like a pickup truck compared with AHI being a tractor trailer, IMO. Literally and figuratively. I like being able to move stuff around without a lot of effort.

[Living Large]

I'm thinking another module could be added to the Aquion stack full time, no switching required.

One stack consists of 8 modules so:

at 59 volts/8 = 7.37 volts per module. 1 extra module would be 66.4 volts, well within the range of both my Outback inverter/charger and Midnite classic

at 40 volts/8 = 5 volts per module. 1 extra module would bring it in at 45 volts, well above the 42 volt cutoff, and equivalent to the 40 volt cutoff with 8 modules.

Problem with low voltage cutoff solved!

This also increases the price, weight and size of a stack by 12.5%. It's an expensive band aid.

[Living Large]

LFP is essentially 100% efficient in terms of amp hours but do not be fooled because amp hours do not mean squat. Listen to this and wrap your head around it because it is important to understand.

What is 1 AH on AHI being charged up at 60 volts? 60 watt hours right? What is 1 AH at discharge when below charge voltage say at 48 volts or all the down toward 80% DOD of 33 volts? Could it be 33 to 48 watt hours? That round trip efficient Northern is speaking about is gobbely gupe Marketers use to make their crappy product sound good. AH efficiency don't mean squat. Even if AH efficiency were 100% like LFP, watt hour efficiency is not because charge voltage is higher than discharge voltages. Good thing about LFP is the flat charge/discharge curve makes the efficiency as high as you possible can get say compared to FLA or AHI.

Thank you for pointing out this nuance. A newbie like me can forget about efficiencies, not having worked with the hardware yet. When the rubber hits the road, a "little" thing like this will be huge.

[northerner]

Man, I wish I was there. Nov & Dec, was about 6 weeks of heavy clouds/storm in northern California. Burned a bunch of fuel. got nearly nothing from solar for 6 weeks

I live in northern Alberta, and go through a period from about mid November through to about mid January, where I am heavily reliant on generator power. It basically requires daily generator run time as the sun is relatively low in the sky and only out for 7 to 8 hours. Even haze and high cloud reduces incoming power significantly. On a cold clear day in mid winter, I can receive up to 10 kwh in, from a 2.8 kwh solar array. A month on either side of that period is transitional, where only occasional generator runs are needed, and next to no generator run time beyond that. We do receive plenty of sun here though.

This winter has been cloudier than I've seen in the past. Had about 100 hours of generator run time in December.