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larry_cad's avatar
larry_cad
Explorer II
Mar 27, 2021

House battery life

For several years now I have been conducting a battery life expectancy test with my diesel motorhome. In January 2015, we arrived at Quartzsite for a winter stay, our first shot at Q. Shortly after arriving, it became obvious my house batteries were not in shape for a long boondock stay. I have four 6V house batteries, 2 each in series, connected in parallel. I disconnected all four and tested voltage and it seemed I had two low batteries out of the four. Since I was driving into Phoenix anyway, I stopped at the Interstate Battery store along I10 and bought 2 new GC2-XHD-UTL, 232Ah deep cycle batteries which I installed upon my return.
Of course, best laid plans and all that, I still did not have sufficient power and (since I was not going to Phoenix) decided to replace the other two with Trojan T-105s with 225Ah@20, and 185Ah@5hr available locally in Q. All this took place within a couple of days. My goal was to see which batteries lived longest.

It is now 6 years later and all four are chugging along with no problems. During this time I have monitored water level, and kept the batteries and connections all clean. I have a Magnum Inverter/charger with 3 stage charge function. During the 6 years, I have had to add a nominal amount of distilled water, barely enough to mention.

Last year I took a trip from Ohio to Arizona (four months, july,August,Sept.,Oct), and back. This year we are spending the winter in Florida and two days ago I checked my water. Interestingly the Interstates took the typical nominal water charge, barely 1/4 cup. Meanwhile, the Trojans required a full cup in each cell!

I was surprised by this information and now will keep a much closer eye on those two as I take this as a sign of possible beginning failure.

I'm happy with 6 years out of both sets, just curious about the final outcome. I now have to decide if I will change all four when one or the other fails, or keep the winner going until...........





  • 2oldman wrote:
    Looks like those google pictures aren't going to display. Or they're pictures of a gray oval.


    Should have worked, but redid it anyway. Hope this is better.
  • BFL13 wrote:
    How are the load and charging wires connected on the four 6s? All on one pair or across both pairs? If the former, that pair is working harder than the other "downstream" pair so it might use more water.

    I had a pair of those Interstate 232s banked with a pair of Exide 226s for years no problems. Sometimes I added a pair of Trojan T-1275 12v batts to that so I had six batts in the bank and it all worked great. You can do that if they all have similar charging specc. The different AH sizes don't matter if you load/charge across the whole bunch.

    ISTR those Interstates had calcium to them while the T-105s have the antimony so they would use more water? Mex said something about that. Lately, the Interstate 6s are 225AH same as the T-105s and an Interstate guy told me they are made by Trojan. So if you had the newer 225AH Interstates they would not be "mixed" :)


    There is a 400 amp jumper connected from + to + and from - to - Kinda like I said, in parallel.
  • Looks like those google pictures aren't going to display. Or they're pictures of a gray oval.
  • My current Trojan T125s also seem thirsty compared to previous batteries.
  • How are the load and charging wires connected on the four 6s? All on one pair or across both pairs? If the former, that pair is working harder than the other "downstream" pair so it might use more water.

    I had a pair of those Interstate 232s banked with a pair of Exide 226s for years no problems. Sometimes I added a pair of Trojan T-1275 12v batts to that so I had six batts in the bank and it all worked great. You can do that if they all have similar charging specc. The different AH sizes don't matter if you load/charge across the whole bunch.

    ISTR those Interstates had calcium to them while the T-105s have the antimony so they would use more water? Mex said something about that. Lately, the Interstate 6s are 225AH same as the T-105s and an Interstate guy told me they are made by Trojan. So if you had the newer 225AH Interstates they would not be "mixed" :)

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