batteries 6 volt

I was going to use 8 T-105's which I can get for about $90 foot print 7"X10"
then it was suggested to get 4 L16H-AC, they cost $295  size foot print is 7"X 11.7"

so $720 vs $1200 but half the space.

It looks like almost the same amp hours.

Comments

  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,039 ✭✭✭✭✭
    4 L-16's will give you a manageable, 2 strings of batteries. 8T-105's are going to give you 4 strings which are difficult to keep a equal amount of resistance on. This will cause premature failure of your battery bank as the problem will compound as time goes on unless you spend lots of time monitoring  and even rotating your batteries. Sounds like this is in an RV, especially fun contorting around and among the battery bank. Also you will have double the cells to check, fill and monitor specific gravity on.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • Ako
    Ako Registered Users Posts: 184 ✭✭
    edited March 2017 #3
    What do you mean by rotating batteries exactly Littleharbor , been considering rotating my set of 4x6v L16s so the current flows in the opposite direction through each of them but cant find any evidence to support this other than physically moving them could possibly mix the fluids while doing so . If you have anything that shows rotating batteries is beneficial in other ways i would be most grateful for a link .
    2240 Watt Array  4 x 460 Watt Mono Panels + 2 x 200 Watt Panels
    Victron Smart 150-70 MPPT Charge Controller
    24 volt Battery Bank 4 x 6v 400 Amp/Hr Trojan L16 AGM
    LiFePO4 Lithium 100 Amp/Hr Battery for Backup
    Victron 1600w Multiplus Compact Inverter/Charger
    DC to DC Charger ( Non Isolated )
  • lipets
    lipets Solar Expert Posts: 61 ✭✭
    if your cables are not exactly the same lengths the draw and charge rates are slightly different so rotating is supposed add longevity.

    I rather have all the cables made right.

  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,039 ✭✭✭✭✭
    edited March 2017 #5
      With a DC clamp meter you should be able to monitor amperage going into each individual strings of batteries and decipher which ones are taking more and less amperage. Batteries themselves will have differing amounts of resistance. Add to that varying cable lengths and the compounding negative effects of uneven charging you get progressively worsening uneven  charging.  Because of these problems, multiple strings of batteries are not recommended.
       Here,  http://www.smartgauge.co.uk/batt_con.html   is some info for wiring up parallel strings of batteries. Method #3 , using buss bars and even length cables would be recommended. That being said You really should size your batteries based on your loads and buy the proper sized batteries to avoid having parallel strings in the first place.
      Ako, How are these L-16's configured? 2S2P for 12 volt? If wired as  a 24 volt bank this really doesn't apply. As far as current flowing in the opposite direction, that's not possible. If you are wired for a 12 volt bank you simply need to make your positive and negative connections at opposite, diagonally opposed corners of your bank ala method #2 of the smart gauge link. If you are concerned about mixing the electrolyte in your flooded batteries you should equalize charge them and verify equal state of charge with a hydrometer.
     

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Watt-hours (capacity) will be roughly the same for a given weight and size of any lead acid battery.

    L16s are taller than golf carts, so if your limitation is horizonal space only, yes they take up less space. They also have the advantages of simpler wiring and easier maintenance mentioned above.
    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