New battery bank... 1000 a/hr bank or 1300 a/hr bank?

alyazalyaz Posts: 114Solar Expert ✭✭
The batteries I am considering have a 1000 a/hr or 1300 a/hr size.  Our current bank that is about 12 years old is 1065 a/hrs @ 20 hr rate.  (12 - 2 volt batteries for a 24 volt bank).  Am I missing anything here in my thinking about pros and cons of the two sizes?  I am leaning towards the 1000 a/hr batteries at this point.

1300 a/hr batteries - pros:  they should last longer than the 1000 a/hr batteries because over time they would cycle less; during sunny summer months I can store more solar energy as I am usually floating by about noon.

cons: will require more gen run time in winter and shoulder seasons; cost more than the 1000 a/hr batteries.

Thanks.
3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.

Comments

  • mcgivormcgivor Posts: 2,058Solar Expert ✭✭✭✭
    Depending on how much fuel the generator uses, plus wear tear, and service costs, it may be cheaper to expand PV, if the controllers are not maxed out. This would be for the larger Ah capacity, but one thing missing is how deeply the batteries are discharged, if historically the depth of discharge is shallow the added capacity may be wasted, or not utilized and if you're not using it you're loosing it. Batteries will degrade over time eventually dying even without loads, so sometimes less is more. If you got 12 years out of the current  bank, perhaps the ballance is good, so staying with the same capacity could be the best choice.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • alyazalyaz Posts: 114Solar Expert ✭✭
    edited July 29 #3
    Thanks.  I have been running the batteries down to 24.4v, at the most.   
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
  • westbranchwestbranch Posts: 5,084Solar Expert ✭✭✭✭
    Al, what are your daily Ah used? Looks like you would be getting about 100 Amps max, for charging, out of your system ... Are you anticipating an  uptick in consumption?
     
    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, Hughes1100 Sat Modem
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • BB.BB. Posts: 27,689Super Moderators admin
    Any thoughts about going to 48 vdc battery bank?

    Fewer mppt solar chargers (typically around 80 to 90 amps per controller maximum... A 1,000 ah battery bank would like around 100 to 130 amps of charging current... 500 ah @ 48 volts, 1/2, the charging current.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • alyazalyaz Posts: 114Solar Expert ✭✭
    I would think we are at about 5.5 kwh a day now.  We have adopted yet another dog, which we feed raw, so we have moved to two electric fridges and two small chest freezers.  Greenhouse watering etc....

    I like the sound of a 48v bank but pretty sure I would need a different inverter... off the top of my head I believe I now have the Magnum PAE-4024.  
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
  • Raj174Raj174 Posts: 634Solar Expert ✭✭✭✭
    The Magnum Energy MS4448PAE 4400 Watt Sine Wave inverter 120/240 Volt should be pretty much a drop in replacement. They sell for $1776.00 here at NAWS.

    Rick
    3600W PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 54.4V 207AH LiFePO4 no BMS, 4500W genset.
  • PhotowhitPhotowhit Posts: 4,662Solar Expert ✭✭✭✭
    You already have a working system and even an extra charge controller, as we have discussed before. I'd stick with the working system. I do hope to change when I replace my battery bank. But I'm running nearly half the battery bank you are, a remnant of my previous cabin system and haven't yet bought the proper inverter for my system.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • alyazalyaz Posts: 114Solar Expert ✭✭
    I had considered buying my new batteries from the sponsor, but living in Canada makes the process much more involved.  I could have them shipped to an address in Sumas, WA, but concerned with what may happen at the border when bringing them back.  Seems to be a lot of added tariff talk right now etc.  It is difficult to get a straight answer from the border people...  Oh well.  
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
  • EstragonEstragon Posts: 2,609Registered Users ✭✭✭✭
    I bought most of my system from our hosts (~4 years ago), had it delivered to the ND border, and had no issues crossing the border. Had to pay GST, but that was about it. The batteries I got locally though as shipping costs were prohibitive relative to price difference.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • alyazalyaz Posts: 114Solar Expert ✭✭
    edited August 1 #11
    Just thinking out loud here... so my last dilemna is do I go for the new bank of tubulars ($6248 shipping included) or the Rolls/Surrette 4KS21 ($7500 shipping included).  The Rolls/Surrettes are about 100 a/hr more capacity, and arguably a more tried and true company/technology... something I haven’t mentioned is that our home is up for sale (but seriously because of the remote location it could take years to sell).  So on one hand I don’t want to spend unneeded money, I still seem to like buying and getting quality / value.  :-)
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.
  • mcgivormcgivor Posts: 2,058Solar Expert ✭✭✭✭
    Buy the new batteries and the home will sell, not because the new owner appreciates the fact, it's just how it works, if I want rain I'll pump water for irrigation, if want sun, run the generator, it's a backwards principal. .... or so it seems..
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • EstragonEstragon Posts: 2,609Registered Users ✭✭✭✭
    Rolls are based in Nova Scotia, and I believe warehoused in Vancouver. You may want to check around locally for pricing, or maybe NAWS does a drop ship out of Vancouver?
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • BB.BB. Posts: 27,689Super Moderators admin
    +/- 10% in capacity between batteries is something that you will probably never notice...

    Check the charging voltage of the battery vs your DC input voltage range for your AC inverter/AC to DC battery charger(s)... Rolls (and many "industrial" type batteries have pretty high charging/EQ voltage requirement vs what a "typical" consumer AC inverter can accept...

    Typical AC inverter (even those with good quality) may accept 10.5 to 15 volts (24: 21-30 volts, 48: 42-60 volts)... While the industrial batteries take 16/32/62+ volts to charge. Add that cold batteries take higher voltage to charge (-5 mV per cell per degree C over room temperature, warm batteries--lower voltage; cold batteries--higher voltage). For those of us not in the great white north, the issue of high battery bus voltage faulting the AC inverter DC input voltage alarm, not a common issue. For those of you in the North, can be a real pain in the neck (cannot run AC inverter while charging/EQing a "cold" battery bank using "industrial" batteries--Have to bypass inverter to run AC loads while charging from genset/EQing).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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