Reference books and books for beginners.

2»

Comments

  • Shade
    Shade Registered Users Posts: 23 ✭
    #32
    Re: Reference books and books for beginners.
    Cariboocoot wrote: »
    You will not get "unformed" FLA batteries. They will have been filled with electrolyte, charged to 'form' the plates, and then emptied again. Deterioration begins Day 1 and all you can do is slow it down, not stop it.

    It used to be quite common to ship batteries empty and the electrolyte separately (this before they were deemed 'hazardous material'). The idea was that the shelf life of the empty batteries was longer. They don't do this anymore because it isn't.

    Rule #1: batteries die over time no matter how they are treated.
    Rule #2: you can't change Rule #1.

    So, hypothetical, if I can get unformed batteries, what would the shelf life of those be? I
    am sure that is what we had in the Navy as backups. I do understand that if they were
    formed and then emptied that they would deteriorate, no doubt in my mind on that. I did
    not realized that is what they did. I assumed, my error, that they were what we had in
    the Navy.
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #33
    Re: Reference books and books for beginners.
    BB. wrote: »
    Again, we are talking about commercial batteries... Not saying that there are not other methods--Just that you need to confirm with the mfg/specifications that they are designed for decade(s) of "dry storage":

    http://www.solar-electric.com/deep-cycle-battery-faq.html


    And everything has is pluses and minuses... Forklift batteries will last a long time in service, but you need a supply of distilled (or filtered rain water) as they tend to use more water when charging/equalizing. Also, since ForkLift batteries have higher self discharge (towards the end of their life), I probably would install a 10-20% larger solar array than nominal rules of thumbs would suggest (a fork lift battery near the end of life can have a 1-2% self discharge rate per day).

    -Bill

    Thanks good info. I appreciate all the feed back.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,642 admin
    #34
    Re: Reference books and books for beginners.

    You probably have to call a couple of battery distributors/companies to see if you can find unformed batteries--Just don't know.

    From Battery University comments:

    http://batteryuniversity.com/learn/article/how_to_store_batteries
    On July 18, 2012 at 11:51pm
    John Fetter wrote:
    Martin - If your lead-acid battery has been stored for a very long time, the plates will most likely have become sulfated. That is not good. A sulfated battery refuses to accept a normal charge. There are many different types of products on the market described by their manufacturers as desulfators. Take your pick.

    I stored a lead-acid battery for five years without it becoming sulfated by using the following procedure:
    1. Remove caps. Empty out all the acid and store it separately.
    2. Flush out the battery cells two/three times with reasonably pure water, (can use drinking water), to remove most of the acid.
    3. Fill cells to the maximum with water.
    4. Replace caps. Put into storage.
    5. When the battery is needed, empty out the water.
    6. Fill the cells with the acid that you stored separately.
    7. Charge the battery.
    The battery will accept charge and give virtually 100% of the capacity that it had on the day when you put it in storage. The plates will not be sulfated. The plates will not be buckled. I presume this method can preserve lead-acid batteries in storage for decades.

    On October 5, 2013 at 3:31am

    John Fetter wrote:
    Dinh - I assume you mean lead-acid that has come off the assembly line, never been filled with acid, also known as unformed. I recently used batteries that came off the assembly line in 2002, were kept in storage all this time, filled them, formed them and they worked just fine.


    No idea if either methods are practical or even work as offered (I don't know anything about John Fetter)... The first one would not work if the batteries drop below freezing (pure water will freeze and destroy battery).

    In general, for every 10C (18F) you drop the storage temperature, the battery will last 2x longer (storage, lower self discharge, lower sulfation rates). If you can store them near freezing (0C), they should last 4x longer in storage (you still need to follow all the rules for keeping filled batteries charged, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #35
    Re: Reference books and books for beginners.
    BB. wrote: »
    You probably have to call a couple of battery distributors/companies to see if you can find unformed batteries--Just don't know.

    From Battery University comments:

    http://batteryuniversity.com/learn/article/how_to_store_batteries

    No idea if either methods are practical or even work as offered (I don't know anything about John Fetter)... The first one would not work if the batteries drop below freezing (pure water will freeze and destroy battery).

    In general, for every 10C (18F) you drop the storage temperature, the battery will last 2x longer (storage, lower self discharge, lower sulfation rates). If you can store them near freezing (0C), they should last 4x longer in storage (you still need to follow all the rules for keeping filled batteries charged, etc.).

    -Bill
    Already emailed Rolls/Surette, I will post their reply.

    I was thinking of putting my batteries in my crawl space
    (I have a 4' clearance in my crawl) the temp in there in
    the cold part of winter is generally 50F and 65F in the
    heat of the summer. This was also to shorten my DC
    runs in my original plans.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,642 admin
    #36
    Re: Reference books and books for beginners.

    Cycling batteries should be "inspected", specific gravity logged, and water added around once per month (minimum).... Plus access issues for moving cells/batteries around/wiring up cabling, etc. I am not a fan of making that a pain in the back by installing a 4' tall space.

    Also, batteries always worry me (non-trivial fire hazard, a bit of acid mist, etc.)... I would think twice about installing under a home in a crawl space.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #37
    Re: Reference books and books for beginners.
    BB. wrote: »
    Cycling batteries should be "inspected", specific gravity logged, and water added around once per month (minimum).... Plus access issues for moving cells/batteries around/wiring up cabling, etc. I am not a fan of making that a pain in the back by installing a 4' tall space.

    Also, batteries always worry me (non-trivial fire hazard, a bit of acid mist, etc.)... I would think twice about installing under a home in a crawl space.

    -Bill

    Access will not be an issue, my access 'hatch' will be right next to the battery rack.
    As far as fire, in the crawl is no better than in the house. I did think about outside
    but the problem there would be hot in the summer and below freezing for 2-3
    months in the winter. Constant cool temps would be better I would think.

    Reminded me of a story about an old Navy buddy of mine, he was trying to tell me
    that they got cold and had snow up in the SC mountains. I asked him how deep his
    water line was buried, he said 6-12 inches. I asked does it every freeze. He replies
    never that deep! I said my line is 48-60 inches deep and has frozen once in 20 years.

    "Cold" is relative... and then there is Canada...
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #38
    Re: Reference books and books for beginners.

    Okay lets see if I am starting to absorb some of this stuff...

    We use 62.4kWh per day of electrical power from the grid.
    That is 62400 Wh per day if I have a 48V battery bank that
    would require 1301 Ah of battery storage at 100% efficiency
    and if assume that the inverter is 90% efficient then that
    would translate to 1446 Ah of battery storage. So round up
    to 1500Ah at 48V. Is my math and concepts correct?
    · Share on Twitter
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    #39
    Re: Reference books and books for beginners.
    Shade wrote: »
    Okay lets see if I am starting to absorb some of this stuff...

    We use 62.4kWh per day of electrical power from the grid.
    That is 62400 Wh per day if I have a 48V battery bank that
    would require 1301 Ah of battery storage at 100% efficiency
    and if assume that the inverter is 90% efficient then that
    would translate to 1446 Ah of battery storage. So round up
    to 1500Ah at 48V. Is my math and concepts correct?

    Most batteries can only be discharged 50% or so. You need to take this into account. Further discharge may be harmful.

    Some, such as Surrette 5000 series can be discharged 80%. Then, things get difficult. One of the reasons I bought my batteries (Trojan) was because they advertized they could discharge 80%. They can, but they are incredibly hard to charge back. To achive 100% SoC I have to charge them at very high voltage for long time (5-7 hours) at least once a week. This introduces inefficiencies, which are hard to quantify, but you need to be somehow prepared for this. My batteries are extremely freaky, but I think, you should be preapred for similar things.

    My point is that you cannot look at the batteries as a reservoirs which you can fill in or empty. They're very picky on how you can charge and discharge them.
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #40
    Re: Reference books and books for beginners.
    NorthGuy wrote: »
    Most batteries can only be discharged 50% or so. You need to take this into account. Further discharge may be harmful.

    Some, such as Surrette 5000 series can be discharged 80%. Then, things get difficult. One of the reasons I bought my batteries (Trojan) was because they advertized they could discharge 80%. They can, but they are incredibly hard to charge back. To achive 100% SoC I have to charge them at very high voltage for long time (5-7 hours) at least once a week. This introduces inefficiencies, which are hard to quantify, but you need to be somehow prepared for this. My batteries are extremely freaky, but I think, you should be preapred for similar things.

    My point is that you cannot look at the batteries as a reservoirs which you can fill in or empty. They're very picky on how you can charge and discharge them.

    Thanks, so if I need X Ah of power my battery bank should be 2X Ah capacity?
    · Share on Twitter
  • mtdoc
    mtdoc Solar Expert Posts: 600 ✭✭
    #41
    Re: Reference books and books for beginners.
    Shade wrote: »
    We use 62.4kWh per day of electrical power from the grid.

    Um. Who wants to take this one..;)

    .....


    OK, sorry Shade but that is a very high amount of energy to supply with PV for an individual home and would likely cost a few hundred thousand dollars.

    First - you generally want to plan on 25% depth of discharge per day (giving you up to 2 days of no sun before getting to the critical - do not exceed- 50% dod)

    So 1300 Ah is 25% of 5200 amp hours of battery!

    To supply that with solar a rough approximation is you want an array that will provide a 10% charge rate = 520 amps. At 48V nominal that = 25k watts.

    But wait - it gets worse!. PV STC ratings are only accurate under ideal conditions. Wire losses, inefficiency in charging and discharging batteries and inverter inefficiencies all add up. The rule of thumb is to use 77% of STC ratings to get a realistic approximation of PV output in full sun.

    So 25k/0.77 = 32.5 K array needed!

    Solar insolation depends on location, season, local weather, shading, etc but a rule of thumb is that on average you can expect a full day in the sun to give you power equal to 2 x PV array STC rated wattage.(more in summer, less in winter, etc)

    32.5 x2 - 65 kwH. Which is back were we started!

    So 5200 AH 48 volt battery bank, 32.5 kW PV array, a whole mess of charge controllers and several inverters, plus lots of copper and associated hardware. You can do the math!

    One word: Conservation.
    · Share on Twitter
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #42
    Re: Reference books and books for beginners.

    32 kw of off grid PV, with associated batteries and hardware is gonna cost somewhere in the neighborhood of $250,000. Do a ten year life cycle cost to the batteries (if you are luck!) and budget another $100,000 to replace them. Pretty expensive kwh, even in an end of the world scenario!

    Tony
    · Share on Twitter
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #43
    Re: Reference books and books for beginners.
    Shade wrote: »
    Thanks, so if I need X Ah of power my battery bank should be 2X Ah capacity?
    Plus any sunless autonomy you desire, I prefer at least three days, so that old make, X battery times 2 times 3 or 6 times the battery capacity or thereabouts. If you skimp on batteries y ou will kill them, if you skmp on PV to charge them, you will kill them.

    T
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #44
    Re: Reference books and books for beginners.
    Shade wrote: »
    Now for those faint of heart about energy consumption, sit down before viewing my graph.

    Attachment not found.

    And I have no idea what the heck happened in Nov and Dec of 2010?

    I did say the above earlier in the thread
    mtdoc wrote: »
    Um. Who wants to take this one..;)

    As I rework the house thing will improve the numbers were more for an exercise,
    as I told my wife we do not have enough acreage for all the panels we would need...
    The barn and shop average an added 50% to that consumption.

    Also in a SHTF situation quite a few of those load would be turned off like the hot
    water heater and the baseboard electric heat. I have a Simple Pump for manual and
    DC operation, so the well pump can be turned off as well.

    My current electrical rate is $0.051 per kWh. Keep in mind I do not have any other
    utility bills, water, sewer, natural gas, propane, heating oil, etc... My company pays
    my phone bill as I work from home...
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #45
    Re: Reference books and books for beginners.

    I guesstimated $150,000; but with the sunless day cap added, $300,000.

    Not realistic at all. But I knew that, I will be starting on my house work
    this winter. Loads will be known and a plan will be developed.
    · Share on Twitter
  • mtdoc
    mtdoc Solar Expert Posts: 600 ✭✭
    #46
    Re: Reference books and books for beginners.
    Shade wrote: »
    Also in a SHTF situation quite a few of those load would be turned off like the hot
    water heater and the baseboard electric heat. I have a Simple Pump for manual and
    DC operation, so the well pump can be turned off as well.

    Heat your home with wood.

    For hot water the realistic options are direct solar hot water, wood fired boiler (or wood stove coil), propane (length of viability depends on tank size), or if you want to do it with PV - a heat pump hot water heater.

    I have a Nyle Geyser which works well and can heat our water (family of 4) with about 2kWh a day.

    Lighting, water pumping, clothes, dish washer and refrigeration with reasonable conservation measures should be less than 10kWh a day for a 3000 sq foot home.
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #47
    Re: Reference books and books for beginners.

    Got my books today.
    Davidson, The New Solar Electric Home
    Boxwell, Solar Electricity Handbook, 2013 Ed.
    Mayfield, PV Design & Installation for Dummies

    Also 3 books on wind.
    Woofenden, Wind Power for Dummies
    Shea, Build your own Small Wind Power System
    Bartman, Homebrew Wind Power

    With wind I will need a 60-80 foot tower to get above the tree line;
    So PV will be my first install, with wind as a possible add on later.
    · Share on Twitter
  • Shade
    Shade Registered Users Posts: 23 ✭
    #48
    Re: Reference books and books for beginners.
    mtdoc wrote: »
    Heat your home with wood.

    For hot water the realistic options are direct solar hot water, wood fired boiler (or wood stove coil), propane (length of viability depends on tank size), or if you want to do it with PV - a heat pump hot water heater.

    I have a Nyle Geyser which works well and can heat our water (family of 4) with about 2kWh a day.

    Lighting, water pumping, clothes, dish washer and refrigeration with reasonable conservation measures should be less than 10kWh a day for a 3000 sq foot home.

    Already heat with wood.
    Direct solar water heat would only be viable 8 months of the year.
    Also my south facing roof is 100% shade and is going to stay that
    way.

    Wood fired heat in a SHTF situation is a viable option and one I have
    explored. For day to day, not interested, if society does not collapse
    I can afford electric hot water, but lowering my electric bill is always
    a good thing.

    Thanks for the link to Nyle that is very interesting technology.
    · Share on Twitter

Categories