Best Low Cost Battery Solution for "Poor Man's" Small RV Solar System

JDark
JDark Registered Users Posts: 18
I now have my 2 100 watt 12 volt panels. This is going to be a 12 volt system. Doing my off grid trailer has sent my credit cards past the roof and so not much left to spend on batteries. The 100AH RV battery is not going to last another 18 months, so getting a second one to pair with that is out. I am going to locate this RV in S. Arizona-can't get much better for sun availability than that. I spoke to someone who used to install there and he told me interstate: 2 6V 100 AH each at $100 per battery. Now we are talking along the lines of my budget.

Price works, but the person installing my system, will have nothing to do w/ interstate batteries. The ones he likes are the top of the line Trojans. I also think cheaper is better, as I am a newbie and do not want to blow expensive batteries in the name of learning how to care for my first battery bank.

There has to be something that is close to bottom dollar [my budget], but better than the bottom of the line interstate. I would too like more than total of 200AH, but not sure I can swing the cost.

After the bills I am creating now are paid off, hopefully a couple years or sooner, I will want to add more panels and batteries as I can afford. So I am just doing now what I can afford, but it's not forever.

Any ideas on inexpensive solutions??? [from there either the installer or I will find the best deal around-I am good at getting the best price once I find the right item].

Comments

  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    Sam's Club or Costco. Golf cart GC-2 batteries. 6 volts each, about 210 AH each. Series = 12 volts and 210 AH total. $80 each plus core, more or less. Not all of their branches sell them, so check around.

    I have used this type since I figured out the typical 12 volt RV battery is crap. About 40 years ago except back then there was no warehouse store to get a great deal from.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    Yep, Mountain Don's got it right, with 200 watts of panels 210 amp hour battery bank is about all you will want on 200 watts of panels, even in Sunny Arizona...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • PNjunction
    PNjunction Solar Expert Posts: 762 ✭✭✭
    Sam's Club or Costco. Golf cart GC-2 batteries. 6 volts each, about 210 AH each. Series = 12 volts and 210 AH total. $80 each plus core, more or less. Not all of their branches sell them, so check around.

    Since those are typically re-badged Deka / East Penn Promaster's, they make excellent learner batteries. Also consider Sears "advanced" gold, which are also Deka/East Penn rebadges.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    The important part is the "Golf Cart" in the name of the product. they are ruggedly built to withstand heavy daily depletion and be quickly recharged
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • cupcake
    cupcake Solar Expert Posts: 254 ✭✭✭
    I use six 12-volt AutoZone "Marine" deep-cycle batteries wired in parallel. They are group 27 batteries, about 110 amp hours each and about $110 ($1 per ah) at your local AutoZone
    They are wired to a 1.1kw pv array in a desert (always sunny) environment.
    ~1.5Kw PV in parallel
    Morningstar MPPT-60 controllers (2) in parallel
    3 Trojan tr-1275's in parallel 450ah total
    Samlex 2,000 watt 12-volt inverter hardwired


  • JDark
    JDark Registered Users Posts: 18
    Those SAMs ones sound affordable and good. I will go check into the Auto Zone ones.
    Thanx
  • JDark
    JDark Registered Users Posts: 18
    Called and Auto Zone only has the starting batteries. Called Sams and the highest they have is 6 v GC-2 at 122 AH each. Those are $112 plus core. Seems kind of overpriced for the amp hours. I was looking to pay closer to that for about 200 or more AH.

    Think I am back to square one again. I think these stores have changed their merchandise recently. Costco stopped carrying "Kirkland" and now only have interstate.
  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    What Sam's Club branch? I see you are in NM and this is a link to the battery the clubs around ABQ carry. At $84.52 plus core

    http://www.samsclub.com/sams/energizer-golf-cart-battery-group-size-gc2/prod6750008.ip?navAction=push

    same as the ones I bought there in 2009 except for the price being a few $$ higher today
    [h=3]Specifications[/h]
    • 6 volt
    • Minutes at 75 AMPS: 107
    • 20 AMP Hour Capacity: 208
    • Reliable Cycling Ability
    • Deep Cycle
    • Gang Vent Design
    • Polypropylene Ribbed Case
    • Post Type: UTL
    • Core Fee May Apply
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    JDark wrote: »
    ... Called Sams and the highest they have is 6 v GC-2 at 122 AH each. Those are $112 plus core ...

    A The GC-2 is really a case size. For Flooded batteries, they should all be in the 200 Ah + Capacity range. Perhaps the person quoting the Capacity misspoke.

    A Golf Cart battery is a REAL Deep-Cycle battery. They are by far, the best value in Deep Cycle batteries especially if you need the Capacity offered by a single string, and are usually commonly-available.

    IMO, Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • softdown
    softdown Solar Expert Posts: 3,895 ✭✭✭✭
    Golf cart batteries generally last at least twice as long as marine deep cycle batteries. They are what you want.

    Only problem I have them is that it takes a lot to make a 48 volt string. They are ideal for 12 volt strings. Use the heaviest copper wire that you can to connect them. There are good arguments for this.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • JDark
    JDark Registered Users Posts: 18
    I live in farthest south, NM now and far from Albq, but all the work is being done in Benson, AZ, they have to be purchased there and I think the Sams I called is the one Sierra Vista, AZ, closest one to Benson, AZ. The guy checked on the the battery specs and went and asked the mgr, also, so I know he did no goof. Found some marine ones at Walmart for a good rate, but after the posts above, I would rather have golf cart. I just need more than 75 to 122AH that the Sams ones have. I found some GC-2 in tucson that were about 200AH at a battery store, but the price seemed very high-almost as much as the trojans Well over 300 for 2. So far the only thing I have seen so far, in my price ballpark is: http://www.walmart.com/ip/20531543?reviews_limit=9& Looks like a very poor battery!

    So I am going to need a cheap place to buy the GC-2 w/ the higher amp hours near Benson.
  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    JDark wrote: »
    So I am going to need a cheap place to buy the GC-2 w/ the higher amp hours near Benson.

    website says in stock at Sam's in....

    Tucson Club (#6692)
    4701 N Stone Ave.

    Tucson, AZ 85704
    (520) 292-9789
    51.5 miles from Benson | See Map
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • JDark
    JDark Registered Users Posts: 18

    website says in stock at Sam's in....

    Tucson Club (#6692)
    4701 N Stone Ave.

    Tucson, AZ 85704
    (520) 292-9789
    51.5 miles from Benson | See Map

    Yes I called and spoke to the guy in the dept and his boss. They have nothing but 75 AH for $85 plus core so that would be 6 X $85 and 112 AH for $122
  • JDark
    JDark Registered Users Posts: 18
    Called the number listed above and they used to carry 6 volts the 75 AH one, but disc and now are only going to stock 8volt. So back to square one again. It looks like I will have to have them freighted after all. Any idea where might be the cheapest.
  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    JDark wrote: »
    Called the number listed above and they used to carry 6 volts the 75 AH one,...........

    I find it hard to believe that person. There are no 75 AH golf cart batteries. There are only one physical size of GC-2 golf cart battery. The AH can vary from about 208 to 225 or so between manufacturers. Plus the website lets me order the ones in the link. The website could be wrong, that has happened to me on occasion. Maybe try ordering online. They email you when ready to be picked up. If you don't pickup within the allotted time they cancel the order and issue a full refund. Too bad it is an hours drive ......

    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Johann
    Johann Solar Expert Posts: 245 ✭✭✭
    What about this battery.
    Sams Club, Duracell 6 volt 215ah $85 http://www.samsclub.com/sams/duracel....ip?navAction=
  • softdown
    softdown Solar Expert Posts: 3,895 ✭✭✭✭
    I think your phone person gave you bad info. Trouble with no training etc. Half the people are brand new and clueless. Sams Club and Costco are the go to stores for golf cart batteries. You will need a core battery or pay another $12...or so. They tend not to be too picky on cores.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Johann
    Johann Solar Expert Posts: 245 ✭✭✭
    Johann wrote: »
    What about this battery.
    Sams Club, Duracell 6 volt 215ah $85 http://www.samsclub.com/sams/duracel....ip?navAction=

    Correction for the zip code 85704
    Sams club http://www.samsclub.com/sams/energizer-6-volt-premium-golf-cart-battery-group-size-gc2/prod6000037.ip?navAction=push
    20 AMP Hour Capacity: 232 , 6 volts, $112,
    Looks like they have those.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    JDark wrote: »
    Called the number listed above and they used to carry 6 volts the 75 AH one, but disc and now are only going to stock 8volt. So back to square one again. It looks like I will have to have them freighted after all. Any idea where might be the cheapest.
    It is possible that they are talking about a 12V 75AH battery, although even that would be an odd capacity for a GC-2 case size.
    SMA SB 3000, old BP panels.
  • wellbuilt
    wellbuilt Solar Expert Posts: 763 ✭✭✭✭
    I bought 2 gc-2 in may and the tag on the wall had a different hr rate for the AH .
    I found the 20hr ah rate and it was 210 AH .
    The prices you quote are the real price.
    The guys don't have a clue .
    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • cupcake
    cupcake Solar Expert Posts: 254 ✭✭✭
    No matter which way you slice it, the going rate is $1 per Amp-Hour on any consumer battery. Of course there are more expensive options, but the going rate is $1 per amp-hour
    ~1.5Kw PV in parallel
    Morningstar MPPT-60 controllers (2) in parallel
    3 Trojan tr-1275's in parallel 450ah total
    Samlex 2,000 watt 12-volt inverter hardwired


  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    cupcake wrote: »
    No matter which way you slice it, the going rate is $1 per Amp-Hour on any consumer battery. Of course there are more expensive options, but the going rate is $1 per amp-hour


    ... at what voltage are you basing that?
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • cupcake
    cupcake Solar Expert Posts: 254 ✭✭✭


    ... at what voltage are you basing that?


    Usable voltages like 12 volts, 24 volts, 48 volts... yes there are 400ah 2-volt batteries - but there are no 2-volt DC-to-AC inverters... thus you need six 2-volt batteries in series to get 12-volts at 400ah

    or you can do 4 100ah 12-volt batteries in parallel giving 400ah total... but either way it all works out to be *about $1 per amp hour


    There is NO WAY to get cheaper batteries (ie low cost, high amp-hours) UNLESS the market demands it. Panels are becoming cheaper becasue the WORLD is in a 'solar bubble' right now with this grid-tied nonsense..leasing equipment..tax rebate bait, etc... that made alot of good cheap panels, but these systems are grid-tied, thus the battery market doesnt reduce the price of batteries because the demand is not that high.... only more off gridders will lower deep-cycle battery prices...

    ~1.5Kw PV in parallel
    Morningstar MPPT-60 controllers (2) in parallel
    3 Trojan tr-1275's in parallel 450ah total
    Samlex 2,000 watt 12-volt inverter hardwired


  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    $ per AH is not really a good figure... a 48 volt 100 AH battery holds 8x as much energy as a 100 AH 6 volt battery.

    You really do need to specify at some voltage.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • softdown
    softdown Solar Expert Posts: 3,895 ✭✭✭✭
    In addition, there are significant differences in battery quality, longevity, and technology. AGMs and Gels costs more. Good warrantees can not be free.

    But Cupcakes statement of supply and demand driving down prices is 100% valid. Much of the reason that, for many people, golf cart batteries will likely deliver the most battery for the money.
    BB. wrote: »
    $ per AH is not really a good figure... a 48 volt 100 AH battery holds 8x as much energy as a 100 AH 6 volt battery.

    You really do need to specify at some voltage.

    -Bill

    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdown
    softdown Solar Expert Posts: 3,895 ✭✭✭✭
    Being able to replace a bad battery with a readily available and affordable golf cart battery is pretty enviable. By comparison, I have to pre-pay in person and then wait a couple weeks. Plus I get less battery for the money. Since I made the mistake of starting with 8Ds, I will likely "ride them out" for awhile.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries