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Thread: Off Grid Saltwater Batteries

  1. #1
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    Default Off Grid Saltwater Batteries

    Interesting batteries that are about to be released for Off Grid use

    https://www.altestore.com/store/deep...le-48v-p11988/

    https://www.altestore.com/store/deep...ck-48v-p11941/

    6000 Charge cycles at 50% DOD, that's much better than anything currently out there, and no need for a complicated BMS like LiFePO4 batteries

    I'll have to keep an eye on these to see how well they do after a few years, they may replace my FLA batteries at the BOL if they prove to hold up to time and come down in cost
    Last edited by Tdale; 05-10-2016 at 12:07 PM.
    Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety.

  2. #2
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    they look really good on paper, I hope they work and get cheeper also.

  3. #3
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    The price caught my eye. I haven't checked to see how this $14k unit compares to the Tesla Battery Wall which is $3k. It would have to be pretty impressive to justify that price.
    In a crazy world, it's the crazy man who can get by - and it's about to get cray-cray up in here.

  4. #4
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    There is always Edison batteries which are proven to last for decades.

  5. #5
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    Interesting. Looks like more stuff to break in the larger battery module system, but 30kWh for $15k compares very well to trying to get that capacity using Rolls FLA batteries. Any kind of required and propriety HW, like the battery sensing module makes me wary, but wasn't clear from reading the operators guide whether that was required for a smaller amount of parallel battery 'stacks' or not though. 30kWh would be nice, but overkill for our needs and the 48v system would require some redesign of my system to work too. A 30kWh system with 6000 cycles @ 50% DOD would be the last set of batts I'd have to buy in my lifetime though, we only use about 3-5kWh per day.

    Guess I'm in wait&see mode on this, and other, new batt technology. One requirement for me would be redundancy/fault tolerance, at least the ability to reconfigure the system around failed components like a single bad cell in their stack of 8, for times it wouldn't be possible to contact them and wait for a warranty replacement to arrive.
    Everything marked, everything 'membered. You wait, you'll see.

  6. #6
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    So I've been looking at the cost comparison between different batteries and I think these saltwater batteries may be the ticket if they perform as advertised, even if they don't come down in price

    The Saltwater battery is $15,000 and has approximately 30KW of energy (48Volt @ 579Ah)

    Lets look at the standard FLA batteries most people (myself included) use

    If using T-105's:

    We would need 3 banks wired for 48 Volts (24 batteries) Average cost per battery is $150 so total cost is $3600, figure 1500 charge cycles at 50% DOD (Best case scenario), so we would need a minimum of 4 battery banks over time to compete with the 6000 charge cycles @ 50% DOD with the Saltwater battery, so total cost over time would be at least $14,400

    If using Rolls industrial batteries

    The Rolls 6-CS-17P is a good match for comparison. It's a 6V 546Ah battery and costs $900. We would need 8 of them, so $7200, Cycle life at 50% DOD is 3000 cycles (realistic goal with the 5000 series) so we would need 2 banks over time to equal the 6000 charge cycles of the saltwater battery, total cost is roughly $14,400 for the Rolls.

    IMHO Rolls are a better option than the T-105's because they are the same or lower cost over time and you only have one battery bank to deal with instead of running 3 in parallel.

    If using LiFePO4 batteries:

    Average cost per 3.2V 200Ah cell is $300, we would need 48 of them to equal the Saltwater battery so roughly $15,000 for the battery bank, We would still need a BMS but they are not too expensive these days so that's included in the cost above. We can estimate 4000 charge cycles at 50% DOD with prismatic LiFePO4 batteries, so the salt water battery will get an additional 2000 charge cycles at the same cost, that's a 50% improvement and the Saltwater batteries do not require a BMS so less to go wrong.

    If using NiFe Batteries:

    The cost is staggering.

    $3600 for a 12V 300Ah battery, (https://www.altestore.com/store/deep...ah-12v-p12018/) we would need 8 of them (two 300Ah banks run parallel) so $29,000 and the cycle life is a contested area. I have no experiance with Iron batteries but every chart I have looked at says 3000 to 4000 charge cycles at 50% DOD, I know people claim that NiFe batteries last a lifetime, but the charts don't show this to be true. Also NiFe batteries have Horrible charging efficiencies (50% to 60%), so I ruled them out a long time ago for my BOL.

    So it appears that the Saltwater batteries are going to be cost effective if they live up to the claims made by Aquion Energy.

    So why go with saltwater over FLA batteries. Well FLA batteries have a lot of disadvantages like sulfidation, stratification, the need to equalize the charge monthly, poor charge efficiency at the top 20% of the charge cycle (which is where most Off Grid systems stay), hazardous material when you dispose of them, Damage occurs if you go past 80% DOD, the list goes on and on

    Aquion Energy claims that Saltwater batteries do not suffer any of these handicaps. I'm definitely going to be keeping an eye on how they do after a few years of real world testing.
    Last edited by Tdale; 05-11-2016 at 01:32 PM.
    Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety.

  7. #7
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    Tesla PowerWall -

    Capacity - 7 kWh
    Price - $3000

    Technology - Lithium Ion

    Cycle Lifetime - 5000 under warranty

    https://en.wikipedia.org/wiki/Tesla_Powerwall
    A bigger battery called Powerpack, that can store 100 kWh of electricity, is projected to be available for industrial consumers, reaching a price point of $250/kWh...

    When originally announced in 2015, there were to be two models of Powerwall delivered: 10 kWh capacity for backup applications and 7 kWh capacity for daily cycle applications.[6] But by March 2016, Tesla had "quietly removed all references to its 10-kilowatt-hour residential battery from the Powerwall website, as well as the company’s press kit. The company's smaller battery designed for daily cycling is all that remains.".
    So basically 4-5 of the Tesla PowerWall would be equivalent to the Saltwater, and roughly the same price.
    In a crazy world, it's the crazy man who can get by - and it's about to get cray-cray up in here.

  8. #8
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    Quote Originally Posted by bruss01 View Post
    Tesla PowerWall -

    Capacity - 7 kWh
    Price - $3000

    Technology - Lithium Ion

    Cycle Lifetime - 5000 under warranty

    https://en.wikipedia.org/wiki/Tesla_Powerwall


    So basically 4-5 of the Tesla PowerWall would be equivalent to the Saltwater, and roughly the same price.
    No doubt LiFePO4 is a good technology.

    I wonder what the cycle life on the Tesla Power Wall is with a daily 20% DOD. This is where I plan my systems, to give capacity for a few days of rain, clouds, etc.

    The saltwater battery is claiming 16,000 cycles at 20% DOD, that's over 43 years of daily use.

    Chart comparing the Saltwater battery to a Rolls 5000 Series Industrial battery (Rolls on the Left, Aquion on the right)


    (Source https://www.altestore.com/blog/2016/...nergy-storage/)

    I wonder if it's all hype or if they will live up to the claims

    The Saltwater batteries do have some distinct disadvantages when compared to LiFePO4:

    For example the maximum discharge rate is much lower as is the maximum charge rate, but these will not be an issue for a well set-up off grid installation if you can afford spare capacity. If you need high discharge rates or high charging rates LiFePO4 is still the king

    Also charge efficiency on LiFePO4 is a little better 95% vs 90%, but the claimed Saltwater efficiencies are still much better than FLA which are horrible (Under 60%) in the top 20% of the battery http://www.otherpower.com/images/sci...Efficiency.pdf
    Last edited by Tdale; 05-11-2016 at 08:55 PM.
    Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety.

  9. #9
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    Default Guess I won''t have to watch this one any more

    http://www.foxnews.com/politics/2017...ankruptcy.html

    Seven years after Aquion Energy received a $5.2 million stimulus-tied grant from the federal government, the Pennsylvania company on Wednesday filed for Chapter 11 bankruptcy.

  10. #10
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    As much as I hate it, these companies are playing "the game". Maybe not the individuals with the idea and the passion, but the "investors". There are people who have figured out the system and make bank, these people need a big dose of conscience.
    Don't bring skittles to a gun fight.

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