48v Small System

Discussion in 'Alternative Energy' started by RazrRebel, May 2, 2018.

  1. RazrRebel

    RazrRebel Well-Known Member

    Apr 16, 2013
    Southwest Va.
    Ok I have 4 T1275 batteries from my golf cart. They are rated at 12v , 150 amp hours each. I also have the 48v, 13 Amp charger. If i have the four in series for 48v, then I would only have 150 amp hours of capacity right? Right now I have a 32" flat screen tv. A DVD player, and four led lamps. Just wondering if I have enough batteries to run what I have now. If so I'll be charging from a small generator. This is all I have, as I had a house fire, and the golf cart body took major damage. If I do have enough batteries, what would be a good 48v invertor for now and later down the road "bigger system" and will I need a charge controller?
  2. ET1 SS

    ET1 SS zone 5 - riverfrontage Supporter

    Oct 22, 2005
    Forests of maine

    A charge controller has different modes; bulk charge, float charge, equalize charge, etc. These are needed for long-term battery health. They are each set at different voltages, depending on the battery manufacturer specs.

    I run a 48vdc system.

  3. wy_white_wolf

    wy_white_wolf Just howling at the moon

    Oct 14, 2004
    You won't need a charge controller unless you add solar to the system. I assume the charger you have if for a golf cart and should have it's own charge controller built in.

    As far as having enough power until you total up the usage (watt-hours) we can't answer that.

    I would suggest about a 500-600w pure sine wave inverter. Anything larger will waste energy and may not work if you happen to only be running 1 or 2 of the LEDs bulbs (minimum load requirements).

  4. MichaelK!

    MichaelK! Well-Known Member

    Oct 22, 2010
    Yes, you have only 150 Amphours of capacity, but that's at 48Volts. So, you have 150AH X 48V = 7200 Watthours of electricity. Assuming you don't want to ever deplete your batteries lower than 50%, and routinely deplete them less than 20%, you can get 3.6kwh and 1.4kwh of power respectively out of them. You yourself will have to add up your loads, but lets say the TV uses 100 watts per hour, the DVD player 50 watts, and the LEDs combined 50. At 200 watts continuous consumption, you can drain your batteries for more than 6 hours before hitting the 20% mark, and 18 hours of continuous use before hitting 50%.

    This inverter could work for you.

    If you want to go premium with the thought of future expansion, I'd go with this hold-house inverter. Note that it's designed to be hard-wired into your main electrical panel.

    About 750 watts of solar panels could easily replace the 20% usage above on a typical winter's day.

    You want to charge at about 1/10 of your amphour capacity, so to get 15amps at ~59.3V (Trojan spec) you'll need
    15amphour X 59.3V X .8derating ~ 710 watts of panels. Get three 250watt grid-ties, wire them in series, and funnel that into a MPPT controller. Your batteries will stay happy with that configuration.

    If your real-world numbers turn out to be different, just replace my examples with yours and do the math.
    As you enlarge the capacity of your system, you can add more panels, then add bigger batteries, such as Trojan's L16s, which would bring your storage capacity to 18kwh. You'll need 2700 watts of panels though to keep a battery bank that size fully charged, but you get almost triple your daily capacity.
    Last edited: May 14, 2018