UPDATE- Solar PV's 20 (6V) batteries

Hi everyone,
After acquiring 20 (6V) lead acid batteries (160Ah per battery) I had to decide which configuration was best in order to use them.
So after much (con?) figuring.... I decided put them in 24V arrays .....so that means..... I can at least put an electrical charge into the (5) 24V arrays simultaneously by using the 24Volt charger from my dozer and connecting the 5 arrays in series?
Is this correct?
Any comments on this?

Next summer when I start using power tools inn the form of 120Vac I will need to convert 24Vdc to 120Vac.

Any comments on doing this? If not,

1) What type of inverter should I use?
2) How can I monitor battery usage (depletion)?
3)

I will be more able to select and operate a solar PV and charging system next summer

Please post comments.

BTW: Discharge [email protected] 1.75VPC is 8hr 25.0, 5hr 35.2, 4hr 41.4.
what does all that mean?
THANKS
KEVIN.

Comments

  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    inverter suggestion:

    True (pure) Sine wave, with continuous wattage rating at least 2x the run power of your highest power tool. The idle/standby power will not be too much different, but the heavy surge needed to spin up a large tool motor, will tend to shutdown the inverter, as it senses an overload condition.
    This will likely be an expensive inverter. $$ A mod-sine inverter will likely fry power tools, unless they are stamped AC/DC.

    24v charger suggestion:
    Automotive chargers, even a 24V one, will likely leave your 24V system undercharged, as they don't quite reach Float Voltage, and seldom have an equalize setting.
    Get a charger designed for 24V Deep cycle battery banks, that has at least 3 stage charging with Equalize
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • westbranchwestbranch Solar Expert Posts: 5,153 ✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    re your BTW I think , Ctrewzer will probably corct me if wrong, the munbers should be read as

    Discharge rating. TO (reach) 1.75VPC is:
    8hr @ 25.0 amps, 5hr @ 35.2 amps, 4hr @ 41.4 amps.

    the 1.75 v MUST be measured under load.

    HTH
    Eric
     
    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
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Some other problems come to mind.

    1)
    You will be running 4 batteries in series to get 24V
    &
    I'll assume you plan to parallel 5 strings of 4, to get a 800AH bank.

    If you have taken the bank down to 50% charge, you have pulled 400 amps out, which to replace at a C/10 (one tenth of Capacity) charge rate, requires a charger of about 40
    Amps, for at least 5 hours. Faster charge rates may overheat and warp the cells.

    morning edit after coffee : 40A charger for 10 hours, not 5. Pretty stiff for an alternator, as they heat up, their output drops quickly.


    2) parallel strings : Past 3 strings, and you get into weird management issues, where 1 string will have a higher resistance, and another will have lower resistance, causing 1 string to age faster. You need perfect cables and connectors to share the current evenly, which is tough to do.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    hello everyone,

    I am going to attempt to charge to my (5) 24Volt arrays ..... using the alternator from my buldozer (same voltage).

    I am familiar with 12Volt chargers that plug into the wall and apply 8, 4 then 2 amps charge as the batteries regain their charge? Bulk, maintenance and float?

    Q: So, are you saying the bulldozer will not charge deep cycle storage batteries from its alternator?

    If I buy a Deep Cycle battery charger? How will that work ? If I only have the dozer for now?

    There is apossiblity that the neighbor might show up with his portable generator? If I ask him

    Any suggestions?

    I am new to this

    Kevin
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Kevin,

    The discharge rate specs provide an indication of total battery capacity based on certain time and/or load conditions. The common spec is 1.75 Volts per cell (Vpc), which is the voltage of a fully discharged single battery cell under load at 77 degrees F. For a typical 12 V battery with six cells, this spec says that the battery is fully discharged when it reaches 10.5 V under load.

    The “8 hr, 25 A” spec means that the healthy and fully-charged battery can sustain a 25 A load for 8 hours at 77 F until the single cell voltage drops to 1.75 Vpc, or 5.25 V for a nominal 6 V battery. This suggests a total battery capacity of 25 A x 8 hours = 200 Ah.

    The common standard battery capacity spec is based on a 20 hour discharge period. Based on the specs provides, I would estimated the 20 hours capacity of each battery to be ~250 Ah, or 12.5 A x 20 hours.

    As a practical matter, fully discharging a battery greatly reduces its useful life. Typical average daily discharge is in the 10% to 20% range, and batteries are rarely discharged below 50% stage of charge (SOC).

    Accordingly, the actual nominal total capacity of your 24 V battery bank is likely ~1,000 Ah, cased on the estimated 20 hours spec. However, typical daily discharge should only be in the 100 Ah to 200 Ah range, and you avoid taking more than 500 Ah from the batteries before recharging them.

    Flooded-cell deep-cycle batteries require a four-stage charger for proper charging and maintenance: bulk, absorption, float, and equalization. For a 24 V system, the target voltage for the latter three stages should be ~29.6 V, 26.4 V, and ~31 V, all at ~77 F. Cold batteries require higher voltages, and warm/hot batteries require lower voltages. The resting voltage (no loads or charging for at least three hours) for your "24 V" battery bank will be ~25.4 V.


    Automotive/truck/dozer alternators are spec’d to recharge starting (SLI) batteries, not deep-cycle batteries. Accordingly, I doubt that your dozer alternator will be able to properly charge the battery bank.

    Trojan Battery recommends a charge rated at ~10% to 13% of battery capacity. For your 1,000 Ah battery bank, that would be something in the 100 A to 130 A range, at 24 V to 31 V nominal.

    You should use a true sine wave inverter. Your power tools and other motorized loads will likely run cooler and last longer. The size of the inverter (on Watts) will depend on your loads.

    One very good and rugged inverter to consider is the OutBack VFX3524. It can deliver 3500 W continuously, and it includes an 85 A four-stage charger that can powered from a generator. Although <100 A, the 85 A charger is big enough for the 1,000 Ah battery bank. It ain't cheap, but it's worth the price.



    You’d need an 120 VAC generator rated at ~3,600 W continuous, a 3,600 W (continuous) 120/240 V generator with a balancing transformer, or an ~7,200 W (continuous) 120/240 V generator to run the 3524’s charger.

    A battery monitor is required to monitor a battery bank’s SOC. The Xantrex Link-10 is a good choice.

    HTH,
    Jim / crewzer
  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Jim,
    On the same subject ......a Vietnam war veteran has a 28Vdc generator for sale. It used to power lights in rice fields. The motor is completely submersible.
    Q: Would this 28Vdc generator be capable of producing bulk, absorption, float and equalization voltage after I hook it up to a decent charge controller....that is. ??
    I still will be charging the same (5) 24V arrays @ 800a/h each
    Then I might use the same charge controller for some solar panels when/if I get money to install some? and then be able to switch back and forth between supply fields.
    Am I getting any closer ? or further from reality?
    What should the output of the generator be? other than 28V? to work this system?
    What kind of controller?
    Kevin
    BTW: Will a Prosine 1800W inverter work with this system? I think it will. I don't need a 4 stage charger on my inverter do I?..... if the generator is 28V
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries
    BTW: Will a Prosine 1800W inverter work with this system? I think it will. I don't need a 4 stage charger on my inverter do I?..... if the generator is 28V

    You will sometimes (winter) need 30V to recharge a 24V bank (you have to PUSH electrons back into the battery, and need extra force to get them in) so, 28VDC is marginal. You also need at least 40 AMPS capacity of charger, to recharge in a reasonable time. (50% discharge, needs 10 hours at 40Amps or 20 hours at 20amps)

    The charge controller monitors the batteries voltage as it charges, and reduces the current as it approaches "full" so it does not overheat the cells, and then applies an equalization charge at various intervals to maintain battery pack health.

    Forget Automotive Chargers and batteries. Except for using lead inside, and copper wires, this is VERY DIFFERENT, and you can quickly ruin your battery bank $$.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Hi Mike,
    Looks like I am getting a 120Vac generator then.
    I am getting quite an education about batteries. Now I see why you say cut down on the number of batteries (20)6V
    I wish I knew how much they have discharged!
    What do you think about those devices that "shake" the sulfation from the plates? Ever heard of them? Do they work?...Q: if the batteries have discharged what is the best procedure? I have not put them in strings or arrays (not yet?)
    Buss bar and connectors are all there apparently. I haven't seen these batteries since June 2007.
    Exide CA-9's
    Kevin
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Get these batteries charged ASAP, but it's likely too late, self-discharge may have taken them too low, for too long. 72 hours is too long, in my opinion.

    The electronic de-sulphaters *may* sort of work. Most are set to run a SINGLE battery, a bank is too much - they deliver a KHz frequency pulse to the cell, and high impedance wire, or a bank of batteries will dissipate the pulse before it gets into the plates where it's supposed to do something good.

    While looking for generator, look for a 240V one, less amps in the wires to waste as heat loss.
    A 3KW @ 240V should do it. Is a generator going to be your only recharge source ? Running a genset for 3 hours a day will get boorish after a month of hauling gas, changing oil....
    (maybe look at a low speed diesel ?)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Hi Mike,
    Yeah.... I've been looking at diesel generators over on Smokstak.com.
    Q: If I buy a diesel/welder then they often have a DC output for welding. Would that be helpfull to get a DC charge into these batteries? If DC voltage was adequate and amperage was controllable?
    I'm thinking of Lincoln or Hobart? .....can I recharge a bank of (5) 160a/h deep cycle 24V batteries with the output from a decent DC welder.?

    The generator/welder I have in mind is a Honda ew171 and the specifications are at the url below.

    .......would this be possible?

    Kevin
    anyone want some dead batteries??

    http://www.mayberrys.com/honda/gener...dels/ew171.htm

    envelopes2007
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    A welder is not designed to charge batteries, you will, under any conditions, need to have a large Charge Controller, to manage the charge, from Solar, Generator, or Domestic Grid.

    ew171 : DC50-170A Welding 26.5V
    AC output: 4000W max. (33.3A),
    So this would possibly get some charge in dead batteries, but 26.5V is not quite enough to fully charge batteries, as it's barely over the resting voltage.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • westbranchwestbranch Solar Expert Posts: 5,153 ✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Kevin, are you sure they are dead? don't give up just yet.

    If you were closer 8) I might go for a set, but they are off at your Island retreat, right?

    Cheers
    Eric
     
    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
  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Hi Eric,
    Willies puddle... heh?
    I'm not sure they are completely dead....... just a little bit dazed and confused??
    I think the posters here are painting a "worst case scenario" for me..
    First thing I need to do though....... is to check their existing SOC? I will
    1) read the voltage across the terminals
    2) measure the specific gravity of the electrolyte and
    3) determine how much they are currently discharged.

    Then I have two options
    a) Connect the alternator from the engine of my Komatsu dozer to the 24V @ 800 a/h arrays for an unspecified length of time or
    b) Connect the 26.5Vdc output @90 amps of a Honda welder/generator to these same 24V arrays for a similar undetermind amount of time.

    If this is correct? Will I be able to successfully "bulk" charge these Exide 24V arrays?

    Then I could finish them off? with a 120Vac battery charger plugged in to the AC side of a 4KW generator?
    Does this sounding at all possible to anybody?
    Last question,
    Q: Can I put a charge controller into the system? safely and securely? and which one is best?
    Surely, the charge controller doesn't care where the DC voltage comes from ??
    Does it care if it came from a generator/welder or a PV?

    Advise me please .......Oh, wise one(s)!


    Kevin

    ISNTT
    (i'm still new to this)

    Kevin
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries
    Then I could finish them off?

    You just might !

    1) the Komatsu dozer alternator is likely way too small to charge the batteries, it will likely burn up. I'd guess it's maybe a 35A alternator, to only recharge the starter battery. It , as has been stated before, is set several volts too low to really get much into the batteries, unless they are nearly dead.
    bad idea

    2) As I suggested before, you need a 3 or 4 stage charge controller to manage the output of your welder, you could let 90amps loose on your battery bank, but with out meters, you'll have no idea whats happening, till something DOES happen. (generator smokes, batteries boil, 90Amps melts something.)
    another bad idea

    You can do what you want, but I believe you don't know enough about what you are doing, to start "MacGyvering" it. http://en.wikipedia.org/wiki/MacGyver#MacGyverisms
    ... it's your battery bank, and your skin.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • westbranchwestbranch Solar Expert Posts: 5,153 ✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Mike, am I off target in thinking, since Kevin doesnt have any PV equipment thas yet, that he could (should) get a charger/inverter (inverter/charger?) that he can use later when he does get some panels. Powered off the genset.

    Eric
     
    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
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries
    crewzer wrote: »
    ::: snip :::
    Flooded-cell deep-cycle batteries require a four-stage charger for proper charging and maintenance: bulk, absorption, float, and equalization. For a 24 V system, the target voltage for the latter three stages should be ~29.6 V, 26.4 V, and ~31 V, all at ~77 F. Cold batteries require higher voltages, and warm/hot batteries require lower voltages. The resting voltage (no loads or charging for at least three hours) for your "24 V" battery bank will be ~25.4 V.
    ::: snip :::
    One very good and rugged inverter to consider is the OutBack VFX3524. It can deliver 3500 W continuously, and it includes an 85 A four-stage charger that can powered from a generator. Although <100 A, the 85 A charger is big enough for the 1,000 Ah battery bank. It ain't cheap, but it's worth the price.

    You’d need an 120 VAC generator rated at ~3,600 W continuous, a 3,600 W (continuous) 120/240 V generator with a balancing transformer, or an ~7,200 W (continuous) 120/240 V generator to run the 3524’s charger.
    ::: snip :::

    With/without solar PV, you still need a proper charge controller. You can hook your dozer, welder or generator to it, and let it automatically manage the battery charging. (once you configure the controller to your specific bank)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Mike and Eric,
    Gettin 24Volts into a battery is nothin' compared to getting something into my brain!! .....way to-oo much useless stuff in there like birthdays, feelings and other peoples pin numbers!!
    You are right I ain't no McGuyver!!.
    .
    1) 120VAC @ 3600W continuous
    2) 120/240V generator with transformer
    3) 120/240V generator @ 7200W continuous
    I am assuming (then) that all three of these options can be found on gas powered welding machines..... That is so-o good!.

    I am also assuming that the VFX3524 would love to be supplied by power from a new/used gas powered welding machine so long as it is NOt the Honda ew171.

    Am I correct in saying the Honda ew171 does not meet the power requirements from its DC side but will have lots of power from its AC side?

    The VFX3524 will operate from the Hondas ew171 AC side (and then I will live to thank every body for contributing to this site )

    Is the VFX3524 switchable from different sources of power. I only have sun in summer.

    Am I correct? Did I loseanything? Did I get everything I need now to get a charge safely into my batteries before Xmas?

    Hey I just realized yesterday what NAWS stands for!!

    Kevin
  • mike95490mike95490 Solar Expert Posts: 8,429 ✭✭✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    crewzer should be able to answer that, I've never used outback products, but he's the one who suggested it.

    The Honda ew171 welder/gen should, from it's 30A 120V twist-loc outlet, power that VFX3524 A-OK


    Mike

    http://www.mayberrys.com/honda/generator/models/ew171.htm
    http://store.solar-electric.com/vfx3524.html no grid intertie
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    Crewzer,
    OK...so, I pay $2,000 for an outback VFX2524 and consider it an investment to protect my health, batteries and the environment.
    Then I come to use the batteries.....and I need an inverter rated at twice the power rating of the my power tools that i will be operating.
    When I use the bank i need to monitor the SOC so I will know when to fire up the old generator again!
    DC supply?..... is of NO benefit me, my batteries or my wallet! Is this TRUE.

    I will have AC generation and can use the OUTback inverter but what about DC supply? When I get PV's will I need anew controller?
    Pardon me for being so dumb?
    But the forum said General topics!! couldn't find one for dumb topics!!
    Guess I'd like to purchase just one controller (not two)
    Kevin
  • H2SO4_guyH2SO4_guy Solar Expert Posts: 213 ✭✭✭
    Re: UPDATE- Solar PV's 20 (6V) batteries

    You might consider going with a 48 volt battery bank with a few spare batterys. It depends on your budget. Mine was quite small. Exeltech inverters are wonderful, I have two. 1100 watts continuous, and 2200 watts surge for motor startup. Average cost: $300 each off of eBay. These are pure sinewave and they rock. About $1100 new. They are phone companies that get rid of these occasionally and they still work well. MTBF (Mean Time Between Failures) is 20 years!

    If you have acces to mains power (grid), then think about the Harbor freight chargers. On sale they are about $20. 6 amps / 2 amps and 6 amps @ 6 volts. Important if you are charging a single battery. Then you can rotate them in and out of the strings, if you have a problem with one or two you have spares. It makes the strings last much longer. Most battery packs die because of the failure of only one or two units, and you would have four spares! The chargers can be hooked in series and then you have a 48 volt 6 amp charger. It works, I have done the exact same thing. That way you only have two stings of batteries, and much easier to deal with.

    I get used batteries cheap, and then charge them SLOWLY the first time, then pulse charge them for a week each to BLAST the lead sulfate crystals off of the plates. It can extend the capacity of the packs.

    Let us know!

    Skip in Kansas City
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
  • System2System2 Posts: 6,290 admin
    Re: UPDATE- Solar PV's 20 (6V) batteries

    thanks for the info on 48V systems.....I can't decide which way to go because ebay has xantrex 12V pure sinewave inverter/chargers for just $800. right now......and thats about 1/2 price!!
    So, I'm not only confused but tired right now!
    I'll re-read your post am.

    NO GRID.....will that change your post?
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