FLA batteries or lithium?

jrcent
jrcent Registered Users Posts: 47 ✭✭
I went into a local shop to buy new  batteries. I was planning on upgrading to 48v with 6v lead acid batteries. I was advised against it and was told  to stay  24v and get 12v lithium batteries instead. 

Ah fla per ah lithium ? Cost per ah?

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    "I'm a sales droid" and I can sell you something that makes me $30 or $300 commission. If course the $13,000 dollar battery is better for me.  And if it's good for me, it's good for you. 

    Unless you have a special need that currently can only be met with Li, stick with plain flooded.  In 5 years when you need new batteries, hopefully the Li options will be better.
    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 ,

  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    Bang for the buck is still flooded lead acid, golf cart GC-2 format. They are way more forgiving than any other format. One mistake with lithium and its big bucks.
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
  • jrcent
    jrcent Registered Users Posts: 47 ✭✭
    I've been reading old posts here and the "I refuse to sell anything but the best " speal was sort of refreshing from the dollar store and cheap Ebay crap but selling me stuff I can't afford isn't going to work either. 

    I think that staying ~90% charged by having the right amount of charger and loading  will work really good. I've learned a lot from this forum in just a few weeks. Thanks 
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    "Most" people have a pretty high risk of "murdering" their first battery bank or two as they learn their systems. Leaving a load turned on during bad weather, visitors at cabin having everything turned on/hair drier running, etc....

    Using a "cheap bank" for the first time or two can help limit the damage to your wallet.

    Another question is your bank's operating temperature... LI Ion are probably better for room to high temperature operation. They do not self heat hardly at all, when compared to lead acid.

    However if your bank runs towards and below freezing during cycling, then Lead Acid is generally a much better choice. Lead Acid can cycle below freezing pretty well (just don't take below 50% state of charge--FLA battery will freeze around -4F):

    https://www.trojanbattery.com/pdf/WP_DeepCycleBatteryStorage_0512.pdf

    And generally, Li Ion should not be cycled at freezing or below temperatures.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited June 2019 #6
    jrcent said:
    I went into a local shop to buy new  batteries. I was planning on upgrading to 48v with 6v lead acid batteries. I was advised against it and was told  to stay  24v and get 12v lithium batteries instead. 

    Ah fla per ah lithium ? Cost per ah?

    What was the reasoning behind the 24V in leu of 48V nominal? Given the choice I would have used 48V, however  all my existing equipment was 24V so it was a logical decision. My experience with both LA and LFP leaves me wondering why anyone would want to use LA. When my current LA batteries die, they will definitely be replaced with LFP, without a second thought, they are far superior in every aspect except initial cost, but even that can be misleading, if the time is taken to do the math the actual cost is very close, at least for a DIY bank. 

    There are many opinions, most based not experience, but rather on fear of the unknown, it's not as complicated as the fear mongers make it out to be, it's actually rather simple. Initially my thoughts were influenced by such imisnformation, but decided to make the switch despite not needing to, i couldn't wait for the dinosaurs to die so I could get out of the jurassic period, didn't want to be caught with my pants around my ankles in a last minute decision, glad I did, ive no regrets.

    One additional point, if temperatures are below freezing without any way to compensate , then perhaps that could be a challenge, but not something so overwhelming to warrant dismal entirely , personally I have no such challenges in a tropical location.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jrcent
    jrcent Registered Users Posts: 47 ✭✭
    Reason for 24v was 48v was overkill for an off grid cabin  and I could run everything from 24v. I tried to explain the lower amps but didn't matter 
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    edited June 2019 #8
    If your peak wattage loads are less than ~2,400-3,600 Watts and your Battery (20 Hour) AH capacity is less than ~800 AH, then a 24 volt battery bank makes sense.

    The other major issue is to look at the available hardware... Sometimes there is a difference in the level automation/connectivity/etc. between 12/24/48 volt devices.

    Do the paper design (and do a 24 vs 48 design too) first and make sure all the major available components meet your needs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited June 2019 #9
    There is merit to the explanation, a part time system may not benifit entirely from higher voltage, but as loads are unknown it's hard to judge either way, if high demand loads are common 48V may help, however in the overall picture it really doesn't matter, 24V or 48V, both would work, just not 12V, even if that was ever a thought.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jrcent
    jrcent Registered Users Posts: 47 ✭✭
    Thanks Bill.  

    So  with  around  3kw requirements  and the cost of lithium batteries  needed for 24v vice the cost for 48v then 24v would be adequate and do what it needs to do. So he wasn't wrong just thinking long term and better technology. Still money I don't have at this time. I can see  "murdering " my first set of  batteries. I also am hoping that battery technology will be better in 3-8 years. 

    I will sit down and figure it out on paper and see. Can always upgrade  later but  another good inverter in 48v after  buying  a 24v one is wasting money.  I feel like if going to go 48v sooner or later  than  sooner is better.  Everything else can be reconfigured from 24 to 48. Inverter is  24 or  48 specific. 
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Li batteries do have a different operational voltage range than Lead Acid--Make sure your AC inverter's input is compatible (or better yet, programmable low voltage/programmable charging setpoints if inverter-charger).

    Li Ion batteries do have better discharge characteristics and higher current support--So as long as your cables are heavy enough to support the 24 volt current (or whatever voltage you choose), it sounds like you are fine.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    One of the reasons that I stick with 24 volts is that DC referigerators are 12/24 volts only and in an inverter failure I still have my lights and referigerators. My average loads are small enough that I do not tax my system running on one bank alone. I do not parallel my battery banks unless nessecary.
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
  • jrcent
    jrcent Registered Users Posts: 47 ✭✭
    edited July 2019 #13
    I like the idea of 2 separate systems  with 1 at 12v and the other  at 24v or 48v which I'm still am trying to decide. Powering a RV for now until cabin is finished 

    Found some information about charging agm batteries  by charging them parallel with a full good battery. Says that it will  help so wanted to try it and see if I can get a little more life from my battery bank. Hopefully it will help. 

    I want "happy batteries " lol
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    jrcent said:
    ...

    Found some information about charging agm batteries  by charging them parallel with a full good battery. Says that it will  help ....
    A full 12v AGM battery cannot recharge another battery to fullness.   AGM batteries generally want 14.5v for full recharge.
    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 ,

  • jrcent
    jrcent Registered Users Posts: 47 ✭✭
    Ok. Thanks Mike 

    Would having a battery charger connected to both batteries work? If one battery is good with a 14.4v charge and the 2nd battery is low and hard to take a charge? Watched a video from Optima showing this. 
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Connecting a depleted battery in parallel with a fully charged one will cause a cascade of current fron the good to the bad, eventually the voltage would stabilize where both are at the same potential. Is this a good idea?  If the depleted battery was at an extremely low state of charge, the current could be extremely high, which would result in arc flash, the high current would likely exceed the maximum charging  current the depleted battery could safety handle and in the case of flooded batteries in particular, there is the risk of a hydrogen explosion.

    Be very careful with batteries, they may appear benign, but have tremendous energy potential, even a 7Ah battery can provide >100A for a brief instant, that's arc welding territory, play safe.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jrcent
    jrcent Registered Users Posts: 47 ✭✭
    That's crazy that the Optima battery company is advertising that as a way to recharge its agm batteries when discharged too low.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    edited July 2019 #18
    Optima are "pure lead" batteries (at least some of them, as I recall) and have some very different aspects to their "behaviour" (they are supposed to be very nice/rugged batteries, if not cheap).

    I believe the paralleling good+dead battery is to get the "dead" battery over ~9-10 volts so that (those charge controllers with reverse polarity detection) will start up the charger.

    Also, if I remember correctly, the Optima batteries are supposed "need" high charging current for best life.

    -Bill "not a battery engineer or sales person" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I run two systems (12v + 48v) and it does have advantages; I run 12vdc loads like LED lights directly, and have a nice little Morningstar inverter (only available in 12v). It does have downsides though in complexity and added components.
    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
  • jrcent
    jrcent Registered Users Posts: 47 ✭✭
    edited July 2019 #20
    BB. said:
    Optima are "pure lead" batteries (at least some of them, as I recall) and have some very different aspects to their "behaviour" (they are supposed to be very nice/rugged batteries, if not cheap).

    I believe the paralleling good+dead battery is to get the "dead" battery over ~9-10 volts so that (those charge controllers with reverse polarity detection) will start up the charger.

    Also, if I remember correctly, the Optima batteries are supposed "need" high charging current for best life.

    -Bill "not a battery engineer or sales person" B.
    So this would only work if under voltage and charger is showing bad battery. Otherwise put the battery that is low on charge and just let it go as long as it takes without inverter on.

    Estragon said:
    I run two systems (12v + 48v) and it does have advantages; I run 12vdc loads like LED lights directly, and have a nice little Morningstar inverter (only available in 12v). It does have downsides though in complexity and added components.
    I just got a morningstar 12v inverter and connected it to my RV coach batteries. I want to use it for nighttime frig and lights (not much more than that for load at night in RV) . So far it is very clean power and very low power draw..

    I want to use my solar system to plug into RV shore power for daytime power (frig, washer,  computer,  TV,  etc...) and supplement with generator and propane as needed. Will eventually be a system for house also . Seems like a good way to make everything run that I need. 
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    JrC,

    I am just taking some guesses at what people are trying to do... As always, the best approach is to get the manual/information direct from the company and their engineers.

    The problem is that many of these batteries are a combination of private label/alternative construction depending on who is asking for the private labeling, are not clear what the battery construction is (AGM, GEL, VRLA), etc... So, identifying what you have and falling back to good practices is always the next step.

    Generally, for deep cycle flooded cell lead acid batteries, nominal rate of charge should be 10% of the battery's 20 Hour capacity (200 AH * 10% = 20 Amp charge)...

    Once the battery goes above ~80%+ SoC, then the battery will naturally start to limit the charging current (down to 1% or less at 100% SoC)... And this assumes the voltage setpoints are to spec (i.e., ~14.75 volts for a FLA battery "absorb" setting).

    Other constructions and chemistries have different requirements. Do not make any assumptions.

    And then there is the world of trying to "recover dead batteries"... All sorts of suggested methods to try and "fix" these batteries. Some people have good rates, others have almost no positive results on recovery. And it also depends on "how the battery failed"... Somethings may help--Other failures, like corroded/failed internal bus/grids, cannot fix).

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