would 2 of these batteries make a good 12v system

trops357
trops357 Registered Users Posts: 7 ✭
in Solar Beginners Corner #1
hooked in series.
Enerwise Large Capacity Lead-Acid DDm 125-33
for $299.00 each
used
is this a really good price, fair, etc?
****************************
****************************

These were produced in December of 2006 and have a Design Life of 20 Years. The Batteries have been tested and present charge is 2.3 v per cell, (3 cells per battery). Due to the high current capacity of these batteries, they should be configured to produce 2 volts per battery, creating, for example, a 6 battery 12 volt system. Batteries measure 9" x 13" x 24"h and weigh 320 lbs. each.

Battery Label Reads:

Type DDm 125-33

2000 AH. NOM.

Cat. No.: 868416-CW

FR Nonspillable

12-2006


From the Manufacturer:
The PowerSafe DDm range offers an ideal solution for large capacity valve regulated lead-acid battery requirements. PowerSafe DDm's steel can design concept, with its integral racking system, provides a cost effective battery system with a compact, quick and simple installation process. With thicker positive plates for extended life, high-integrity unique post seal design, large copper post design for superior high-rate performance, and steel-encased cells providing uniform compression, the DDm is a superior product in performance and service life.



Features & Benefits:
Capacity: 2000Ah

Design Life: 20 years @ 25ºC(77ºF)

Protective steel can design providing uniform cell compression

Superior quality frame design allows maximum heat dissipation

High integrity welded/epoxy dual post seal design

Easy to install, low maintenance VRLA module system



Applications:
Electric Utility/Switchgear

Telecom

Uninterruptible Power Supply

Solar Power



Weight? Each Battery weighs 320 lbs. & Measure 9" x 13" x 24"h
· Share on Twitter

Comments

  • trops357
    trops357 Registered Users Posts: 7 ✭
    #2
    Re: would 2 of these batteries make a good 12v system

    forgot the pics, sorry , noob here
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #3
    Re: would 2 of these batteries make a good 12v system

    Can't say for certain as I live in Canada where everything costs three times what it should ...
    But looking at US prices on comparable 2V cells this seems to be a fairly good deal.

    I have to ask: why are you building such a massive bank for a 12V system? Twelve thousand Watt hours would run my place for ten days!
    · Share on Twitter
  • trops357
    trops357 Registered Users Posts: 7 ✭
    #4
    Re: would 2 of these batteries make a good 12v system
    Cariboocoot wrote: »
    I have to ask: why are you building such a massive bank for a 12V system? Twelve thousand Watt hours would run my place for ten days!


    1 ) because I am new to all this, and have no idea how long this would run my house.I am only trying to run my basement atm, 2 pc, 32" lcd tv, and some LED lighting. If these are more than I need atm , that is OK, cuz it gives me something to grow into.

    2) because I know somwone who is using some harbor frieght pannes with two 6V battery in series for 12V , and they are tall batteries, like in the picture, lead-acid. While he is off-grid, he is not living at a level I, or my wife would call comfortable.

    I dont mind buying more than I need atm, because there is nothing I would rather do than to make the meter run in the other direction, so to speak,. I know in VA the 2-way meter is sposed torun a year before they credit your overage.
    The city told me they could not credit solar back because their meters cant read it.
    but the va code says they have tosupply the 2 way meter and they will be re-imbursed for the cost..so why are they trying to fight me on it?

    I have no panels atm, but I am planing on building my own pannels from evergreen, or is it everbright?? Plenmty soldering electrical experience,
    terrible at spelling. gotta love these spell checkers.

    Thanks for taking time to respond : )
    · Share on Twitter
  • trops357
    trops357 Registered Users Posts: 7 ✭
    #5
    Re: would 2 of these batteries make a good 12v system

    here is some more info on my area.
    I live in southern va , danville. its right on the NC / VA line.
    I have quite a bit of roof area, ( I will get a good measurement soon, someone who cleaned my gutters, is going to clean my nieghbors gutters in a day or two.
    I will get him to measure the side of the roof that gets the sun almost all day.)
    I live at one of the highest points in danville, so not much is blocking the sun on one side. there is a fair breeze quite often too, probally be trying some wind generation too.
    · Share on Twitter
  • trops357
    trops357 Registered Users Posts: 7 ✭
    #6
    Re: would 2 of these batteries make a good 12v system
    Cariboocoot wrote: »
    I have to ask: why are you building such a massive bank for a 12V system? Twelve thousand Watt hours would run my place for ten days!

    Is there another voltage system I should be going for besides 12V?
    really sorry bout the noob questions, I will be reading the forums more.
    I appologize for coming off as " in a hurry" , but I am in a hurry because these batteries are within driving distance, and I dont see anyting comparable in price.
    I actually have not found mcuh at all except brand new stuff, which is out of my budget : (
    But I am new and have not been researching the market long at all. So there must be some lower cost options out there for some of the parts needed in a solar setup. I really would like to eventually have a grid tie-in system.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #7
    Re: would 2 of these batteries make a good 12v system

    You should start your project with a Kill-A-Watt meter and get some real world figures on the power consumption of the devices you wish to run.

    You might also want to consider some grid-tie options, even if the utility won't buy surplus power. Generally the grid-tie is cheaper than off-grid (no batteries) and will reduce your electric bill. Or are you looking for back-up for an unreliable grid?

    Take some time to figure out where you want to go with this and consider all the options before you start spending money.

    As for small-scale wind ... the "breeze" you need is a sustained 20+ mph without turbulence. It tends not to be too viable economically.
    · Share on Twitter
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #8
    Re: would 2 of these batteries make a good 12v system

    Those would work fine. Until you ruined them by not keeping them charged up enough. Chronically undercharging a lead-acid battery is a guaranteed way to ruin it.

    As icarus (Tony) said on other thread (and has been said about a million times on this forum):

    "The recommended charge rate for a battery bank is 5% to 13% of its '20 hour' Amp/hr rating.
    So for every 100 Amp/hrs you want at least 5 Amps of charge current."

    2 6v in series gets you 2000ah@12.

    So you need at least 100a of charging capability. Not that big a deal if you get the power from the grid, but for solar that's quite a lot.

    As an example, one of the forum members here,, 2manytoyz, measured his Harbor Freight kit:

    "The panels are rated at 15 Watts each, or 45 Watts total. But in actual testing, these panels produce about 0.7 Amps per panel, or 2.1 Amps for the array."

    http://2manytoyz.com/solarphase1.html

    So...you would need about 50 of those Harbor Freight kits just to meet the *minimum* charging current for that much battery.
    · Share on Twitter
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #9
    Re: would 2 of these batteries make a good 12v system

    Wow, I don't even have to write anymore,, should I be taking a hint?

    It should be pointed out that if you have the grid available, using a battery based PV system comes at about twice the cost at have the efficiency, leading to a net KWH cost of about 4 times as much as grid tie. Unless you either have a very unreliable grid, or you are worried about a massive, long term, end of the world scenario, you might be much better off looking into a grid tie system.

    That said, if you are interested in pursuing the battery based system, calculate your loads and work backward to design and size a system.

    My quick calculation is, take the name plate rating of a PV system, divide that name plate rating by to to represent all system losses including, PV, wiring, charge controller, inverter, and basic battery charging efficiency, then multiply that number by 4 to represent the average hours of good sun one can expect. (seldom more than 4).

    Most people over estimate the amount of sun they can harvest net/net, they underestimate the loads they will power, and those loads will grow with time. Pv solar systems don't grow very well, so it is much better to start with a proper designed system. I suggest that you read the following links to start:
    http://www.batteryfaq.org/
    http://www.windsun.com/Batteries/Battery_FAQ.htm#Lifespan%20of%20Batteries

    Don't hesitate to ask questions, the only stupid question is the one that isn't asked. There are some very smart folks here who have forgotten more about PV than most of us will ever know,

    Tony

    Ps re-reading your earlier posts regarding your conflict with the city and the utility. I suggest that you contact a local solar contractor or consultant or solar electrician. He can talk you though the process of grid tie, and I don't think there is a utility in the US that won't allow net metering or some for thereof. As I said that before, your dollars will go 4 times as far with grid tie solar rather than battery based.
    · Share on Twitter
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #10
    Re: would 2 of these batteries make a good 12v system

    it is nice to have somebody else say what you've been saying for a change isn't it? i have been able to sit back more myself.:D

    as to those batteries i would say it is a good deal, but telecom batteries aren't pressed into service much so you may not want to discharge them more than say 25% or 30%. your problem is giving them a proper charge as was stated.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #11
    Re: would 2 of these batteries make a good 12v system

    And when you look at the charging-from-solar aspect the deal may not be so good. To get that 100 Amps of current you'd need about 2000 Watts of panels, which come with a pretty big price tag, and at least two charge controllers, about 60 Amps each. That's roughly $5000 in panels and $400 for controllers plus connections, fuses, wire: $6000! Ouch. :cry:
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,641 admin
    #12
    Re: would 2 of these batteries make a good 12v system

    When getting used batteries--check with your local battery recycle shop before you take possession that they will accept those batteries and how much they will pay you or you pay them to properly dispose of the bank.

    Some battery mfg. add a bit of cadmium to product and it can cost you an arm and a leg to "scrap" your "free" set of batteries.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • trops357
    trops357 Registered Users Posts: 7 ✭
    #13
    Re: would 2 of these batteries make a good 12v system
    Cariboocoot wrote: »
    You should start your project with a Kill-A-Watt meter and get some real world figures on the power consumption of the devices you wish to run.

    You might also want to consider some grid-tie options, even if the utility won't buy surplus power. Generally the grid-tie is cheaper than off-grid (no batteries) and will reduce your electric bill. Or are you looking for back-up for an unreliable grid?

    Take some time to figure out where you want to go with this and consider all the options before you start spending money.

    As for small-scale wind ... the "breeze" you need is a sustained 20+ mph without turbulence. It tends not to be too viable economically.

    OK, I can get a meter 2morrow, I will look into grid tie, if that does not use batteries then how do you power at night? By using grid power??
    I want to use as little grid power as possible. So wont I need batteries for night use?
    · Share on Twitter
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #14
    Re: would 2 of these batteries make a good 12v system

    Grid tie works pretty simply. When your PV produces power, you use it. If you create more than you use, you sell it back to the grid at a prescribed rate. When you need more than you produce, (and at night) you buy it back, also at a prescribed rate. If you size a system correctly, your use and your production will be roughly equal, you may sell some back during the day, and buy it back at night.

    Understand, that if you use a battery system to provide power at night, you will have to generate ~30-50% more power just to stay even, AND will have battery costs (that are not insignificant) both to buy and then to replace every 3-10 years depending on usage.

    If you looking to do this to "save money" also realize that solar is going to be more expensive than grid power. Consider doing every conservation step you can do BEFORE you embark on PV. The rule of thumb is for every dollar spent on conservation will save ~$10 in Pv costs.

    Tony
    · Share on Twitter
  • trops357
    trops357 Registered Users Posts: 7 ✭
    #15
    Re: would 2 of these batteries make a good 12v system
    dwh wrote: »
    Those would work fine. Until you ruined them by not keeping them charged up enough. Chronically undercharging a lead-acid battery is a guaranteed way to ruin it.

    As icarus (Tony) said on other thread (and has been said about a million times on this forum):

    "The recommended charge rate for a battery bank is 5% to 13% of its '20 hour' Amp/hr rating.
    So for every 100 Amp/hrs you want at least 5 Amps of charge current."

    2 6v in series gets you 2000ah@12.

    So you need at least 100a of charging capability. Not that big a deal if you get the power from the grid, but for solar that's quite a lot.

    As an example, one of the forum members here,, 2manytoyz, measured his Harbor Freight kit:

    "The panels are rated at 15 Watts each, or 45 Watts total. But in actual testing, these panels produce about 0.7 Amps per panel, or 2.1 Amps for the array."

    http://2manytoyz.com/solarphase1.html

    So...you would need about 50 of those Harbor Freight kits just to meet the *minimum* charging current for that much battery.

    I think I have room for 50, lol. I guess my friend is not having any problem keeping his batteries charged because he uses very little. I would definatly use more than he is . I didnt realize that the panels could not keep the batteries charged. I guess I probally just leave solar alone, all the posts seem to say it costs more than grid power.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,641 admin
    #16
    Re: would 2 of these batteries make a good 12v system

    Off grid / battery backed solar does usually cost more than Grid Power (if you already have power at the property--if you are 10 miles from a power line--may be a different story).

    Very roughly (SWAG):
    • Grid Power: $0.10 - $0.30 per kWHr (California can be more)
    • Grid Tied Power: $0.10 - $0.30 per kWHR (before rebates)
    • Hybrid Inverter (GT+Off-Grid): $0.45 - $0.75 per kWHR (before rebates)
    • Off-Grid Power: $1.00 to $2.00+ per kWHR (no rebates available).
    Now, batteries are probably 1/3rd to 2/3rds the cost of a system (over 20 years)--so, with low cost/no cost batteries, you may really reduce some costs.

    Grid Tied is the most cost effective / least maintenance type system out there... Does not provide any backup power--and some utilities may not let you connect or may have very poor plans that make it economically nonviable.

    Depending on your needs--A solar system can save money outright (in high power cost states like California where we can pay $0.60 per kWH in hot areas with heavy A/C loads).

    Or--if you have multiple week power outages--a Hybrid GT/Off-grid system may make sense to you (solar panels + batteries + genset).

    Don't want to say XYZ won't work--but really comes down to your requirements and how much you want to spend.

    Many times, if you have cheap/reliable Grid Power--A standard home backup generator is a better deal (tie to natural gas or propane tank).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • Dapdan
    Dapdan Solar Expert Posts: 330 ✭✭
    #17
    Re: would 2 of these batteries make a good 12v system

    as a matter of accuracy those pictured battery is actually a 2V cell and not a 6v battery. The single cell pictured has 3 pair terminals to help carry high levels of current discharge and recharge. Therefore he would need 6 of these cells for a twelve volt battery.

    In terms of the cost, based on my experience with these large vrla battery banks I would say it is a good deal considering the age, Ah and the potential life remaining in these large cells particularly if the came from a telecom type application.

    Cheers...
    Damani
    · Share on Twitter
  • Kamala
    Kamala Solar Expert Posts: 452 ✭✭
    #18
    Re: would 2 of these batteries make a good 12v system

    Good call, Dapdan! Helps to count vent caps instead of terminals. Relates to this current thread.
    · Share on Twitter

Categories