House Battery Choice

[desertdeals69]

I have just completed some battery test with confusing results. I constructed a portable solar system using 6 golf cart batteries, 2000 watt inverter/charger, 6 100 watt solar panels, and an MPPT charge controller. This is the identical system we install in motorhomes only this is built on a rolling cart with the panels adjustable for tilt.

For my battery bank test I used:

6 5 year old Interstate GC2-110 61.4 lbs ea

6 new GC2-122 64 lbs ea

and 6 new GC2-107 60 lbs ea, all came from Sam's Club.

For inverter/chargers I used a Xantrex RS2000, SW3000, SW2012, and a Prosine 2000. My load was a electric heater set on low heat just over 1000 watts. The shut off voltage on the inverters were set at 10.6 volts.

The old batteries went an average 2 hours, the 122 went average 4 hours 8 minutes, and the 107 went an average 4 hours. I was replacing the old batteries in my motorhome and since the 107 group was only a few minutes less I went with them. The cost difference was a savings of $169. I don't understand why it turned out this way.

[dickandlois]

DD, did you get hydrometer readings of the batteries your where testing?

Could offer a reason for the readings being different.

Got to ponder you question a little longer!! Will see if there is any information on the battery cavity size and plate construction somewhere, to get a good comparison of any physical differences.

Rich.

[desertdeals69]

I would presume that the plates are a little thicker which is the 4 lb difference in weight. Bottom line is the time the charge will power the inverter. I don't think the hydrometer reading would be important. All the batteries were charged in 3 stages all the way to float.

[dickandlois]

Interstate Battery information link.

http://www.interstatedealers.com/pdf/201535.pdf

Rich.