What make and model batteries do you use?

South AfricaSouth Africa Solar Expert Posts: 295 ✭✭✭
edited February 2016 in Solar Beginners Corner #1
Hi there,

I have been wondering lately, with Tesla Powerwall looming, what make and model batteries are used by men/ woman, the real off-gridders, who have no access to utilities whatsoever?

I.e. the men, to qualify, must do so with a wife, this is important, for us men living alone have a different standard than living with a wife ... my wife told me. :D 

Seriously, why did you choose the make?
And how long would they last / have they lasted you?
At what DOD?
Would you buy them again?
Would you buy Tesla batteries?


  • mike95490mike95490 Solar Expert Posts: 9,362 ✭✭✭✭✭
    First, there is NO tesla powerwall battery, it is fictional.    Rated to be used 1x a week.

    2nd, the off grid life is vastly different for most women, unless they were raised in a mud hut.

    3rd, assume your first set of batteries will be damaged by a mistake you make, so go cheap (but not too cheap)  and expect them to not last as long as they should

    4th  you are going to need a generator, and if you have winter, you need fuel for it, plan it well, you will use it and it's backup a lot

    So, my first set was used L16 batteries, 8 of them to make a 48V bank.  I'd already sized my inverter to handle the well pump, firdge and microwave.    Now I use NiFe batteries.  They are thirsty for water - even more than lead acid is.  And need electrolyte replacement, not looking forward to upending 40 90# batteries to dump 3 gallons of juice out of them, remix and refill them all.
    LFP does look very interesting, but not enough history on them yet,
    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 ,

  • South AfricaSouth Africa Solar Expert Posts: 295 ✭✭✭
    Mike, I laughed out load, re. the fictional Powerwall.

    Re. the wife's, most of us who have done our little solar systems where I am, everything is quite easy, until SWAMBO and her kids gets involved. We found that a woman's needs are men's wants therefor the part of the entire system, i.e. to get the family to understand, takes THE most effort of the entire system.  :D

    So you also started with Trojans. I ended up with T105RE's, 4 of them, as I am using the utilities as backup. Generator, never thank you. Just switch off more stuff. 

    NiFi batteries ... one day when I am all grown up! .... or our Government has brought the grid to its knees. No power failures lately, probably because so many small businesses and mines had scale and / or close down last year, so there is surplus for now.

    LFP batteries, yes, specs sound excellent ... talk is cheap, but money buy's the whiskey.
    When I see real off-gridders go for LFP's batteries before lead acid, that is the day I will look more deeply into them.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    My SO is fairly content, the first inverter, she had to run the hair dryer on the low setting. She even found a 1000W iron at a junk shop. New inverter, things are a bit better. But when we got it we dug the vacuum, and the toaster, kettle, adn the toaster oven out of the kitchen box. So far she hasnt tryed to run them all at once.  But she still occasionally does random things like start watering the garden or run a load of washing in teh evening.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,

  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    edited February 2016 #5
    Started with a used 1100Ah 2V Telecom AGM, thing I didn't know at first was it sat for >4 months on the loading dock at the recovering agent. Got a Blue sea MPPT CC but it could only take 3 - 120W PVs... So it died after 4 years of undercharging, my learner set, $200, scrap value.
    So in the meantime I found this forum 7 years ago and learned a lot...!
    Started looking for a replacement AGM, as in sig line,took 2 years to find the right size, but at least 800Ah by my calculations.  Got these from a 4 yr old install in a  repeater site that was shut down when the small Co.  got swallowed up by Verison, 2 yr left on the warranty...
    They are tough, and SWM BO is learning quite fast, she is yelling at me if the inverter panel shows yellow rather than green...
    I had one near death experience 2 winters ago when we didn't get back, due to deeeep snows, for 2 months rather than 1... 8 volts on a 24 V set, started the gen up and 4 days later, it was happier, added another 4 panels to the array and shut every load off, 3 weekends and she was back up, purring ever since.  This winter we left the inverter on, deliberately, to test the MidNite Monitoring setup...  if something went bad we could be out there in a few days, Problem was /is that the CC and the Server would fight and the CC lost most times, Still a work in progress, RMA in the works. 
    However the battery hung in there, never below 23.3 V even with 3 - 5 day dark spells and a 40W +- constant load for the inverter, modem, WiFi, and bridge and CC.
    BTW, I bought a 48 v battery and split it in 2, so I have a back-up in place, reading about some of the LiFePO4 guys over on the Midnite forum makes me drool...
    Summary, this make of AGM is  very sturdy IMHO, just tough to find.

    Tesla?  WHO???

    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
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    First set of batteries; GC-2, golf cart batteries.  
    From Sam's Club. Why?  .... Price was great.
    Bought in June 2009, installed same month.
    Daily DOD is normally up to a maximum of 20% of the capacity
    Still going. Would I buy them again?  I don't see why not.
    To be fair I guess, I should say that it is a part time recreational property, so does not get used to the same daily cycles as a full time residence. However from may through August of most years it gets used full time. Spring and fall most weekends. Winter; depends...

    Generator on hand for those few times we have extended cloud coverage.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • 2twisty2twisty Solar Expert Posts: 199 ✭✭✭
    I have 16 GC2s (48v bank) that are about a year and a half old.  Many people start with GC2s since they are inexpensive but provide a reasonably good capacity. I have a generator that I use for cloudy days and for those days that I want to get up to float early for a good equalize.

    For my loads, I really need more solar panels. On most days I am able to get to float, but only late in the afternoon.  I'm also only charging at about C/15 rate when on solar only. This is primarily why I will use the generator to give them a good strong charge and EQ every now and again.

    My usual DOD is about 25%.  Sometimes more, sometimes less. I live here full time.
  • karrakkarrak Solar Expert Posts: 326 ✭✭✭✭
    edited February 2016 #8
    My first off-grid setup used second hand flooded NiCd batteries ex railway locomotives that I got for free. They had woeful efficiency of around 70% and you never really knew how much charge they had in them.

    When a friend of mine asked me to put together an off-grid system for them about three years ago I had a look at the different battery technologies and from an operational point of view on paper LFP batteries came out well ahead of other options and we were prepared to take the risk that they would last the distance.

    After nearly three years they are still operating like new. I have seen reports on other forums of no detectable change in operational characteristics of LFP batteries up to six years old in much larger off-grid and grid connected systems than mine. Makes me much more confident that you should get at least ten years use out of them, which is the point at which they become cost competitive with LA batteries.

    My battery is sized at at round 3 days total power usage in mid winter. I don't have a generator. Average daily use is around 20-25% of battery capacity which goes up to 50-70% during cooking binges. The average DOD of my battery is 25% and minimum I have taken it to is around 85%DOD

    If you are happy to use a generator you will probably get a better return on investment by having the battery sized at between 1-2 days total power usage and recharge the battery to around 50%DOD with the generator when it gets to 80%DOD.

    I would definitely buy an LFP battery again if they last the ten years and I don't see any reason why they won't.

    If you use some sort of battery monitoring/management I don't see why you would damage a battery. This goes for LA batteries as well. If you are flying blind without something to warn you that you are damaging your battery them yes you probably do have a good chance of damaging your battery.


    Off-Grid with LFP (LiFePO4) battery, battery Installed April 2013
    32x90Ah Winston cells 2p16s (48V), MPP Solar PIP5048MS 5kW Inverter/80A MPPT controller/60A charger, 1900W of Solar Panels
    modified BMS based on TI bq769x0 cell monitors.
    Homemade overall system monitoring and power management  https://github.com/simat/BatteryMonitor

  • SaiproSaipro Solar Expert Posts: 74 ✭✭
    13 years of using inverters. My typical "AGM" batteries (turns out I've been buying VRLA maliciously labeled and marketed as AGM) typically last a max of 30 months, no thanks to using just the inverter to charge (irregular grid and backup gen).

    Added solar a year ago and swapped out my LFP mini-bank for Trojan T105-RE x 8 for a 48V bank. Currently performing better than when I started. I guess they've attained full capacity now. I'm 80% or more off-grid (grid is very erratic, voltage fluctutates and hardly on for long so most times, I don't switch to grid). One year down the line and I'm happy. Wife with three teenagers in the house (the natural enemies/nemesis of RE and water .... and everything else requiring conservation).
    Semi off-grid

    255W Canadian Solar × 12, 200AH 48V US 185 XC2 bank, Victron Bluesolar MPPT 150/85, Victron CCGX, Victron MultiPlus 48V/5kVA/70A inverter (primary system) Victron Phoenix 48V/375VA inverter (backup for critical loads)

    300W Yingli × 2, Midnite Brat, 200AH 24V bank (powers DC LED security lights)

  • WaterWheelWaterWheel Registered Users Posts: 340 ✭✭✭
    Woman in the house??? double your battery bank or make her get a perm.       Perms don't require hairdryers or curling irons,,, saves more power than a tankless propane water heater.

    1st battery bank on smaller system,    3 AutoZone 12v batteries which lasted about 2 1/2 years running a tiny AC unit in summer and a chest freezer in winter.      Later upgraded to Trojans.

    New larger system has 8 Crown 395amp/hr batteries for 48v.     Too early to tell how they work but they are much happier now that She Who Must Be Obeyed has gotten a perm. 

    Conext XW6848 with PDP, SCP, 80/600 controller, 60/150 controller and Conext battery monitor

    21 SW280 panels on Schletter ground mount

    48v Rolls 6CS 27P

  • MangasMangas Solar Expert Posts: 547 ✭✭✭✭
    edited February 2016 #11
    Sixty four Trojan L16 RE-B flooded cel 6 volt.

    Our family's off grid 4,000 sq ft home has everything a comparable on grid home has and more.

    My rule of thumb is 5-6 years battery replacement cost should run about the same or less than our rural grid utility expense for the same period.  So far it does.  

    Down the road, I don't see utility costs decreasing but I do see battery life increasing and battery costs possibly remaining in parity or maybe better.

    Time will tell.

    Ranch Off Grid System & Custom Home: 2 x pair stacked Schneider XW 5548+ Plus inverters (4), 2 x Schneider MPPT 80-600 Charge Controllers, 2 Xanbus AGS Generator Start and Air Extraction System Controllers, 64 Trojan L16 REB 6v 375 AH Flooded Cel Batteries w/Water Miser Caps, 44 x 185 Sharp Solar Panels, Cummins Onan RS20 KW Propane Water Cooled Genset, ICF Custom House Construction, all appliances, Central A/C, 2 x High Efficiency Variable Speed three ton Central A/C 220v compressors, 2 x Propane furnaces, 2 x Variable Speed Air Handlers, 2 x HD WiFi HVAC Zoned System Controllers
Sign In or Register to comment.