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cliffy49's avatar
cliffy49
Explorer II
Jun 30, 2020

Costco batteries

Just wondering if anyone has purchased the Costco GC@ 6 volt batteries in the last 18-24 months.

I am thinking about converting my single Marine/RV battery to 2 6 volt deep cycle batteries. Since Costco is about a mile and a half from the house they were my first choice. After reading the reviews for the Interstate GC2 I am not sure.

All the reviews I have read on the Costco site are very bad if not down right horrible. I realize that most reviews seem to be written by some one that has had a bad experience with the product, that is why I am asking for any new users or purchasers to give me some insight on there experience.

Thanks in advance for all the help.

17 Replies

  • The golf cart batteries at Sam's Club have good ratings on their website.... Duracell.
  • Not all 6 volt batteries are the same. Buy Industrial not commercial grade and you get what you pay for. Buy cheap get cheap. I bought Trojan t 125 forklift batteries for my first TT. Sold it at 10 years Batts still going strong. Second TT it was a no brainer, bought another set but after 4 years we decided to trade up. Bough a fifth wheel and took the Trojans off of the Sunnybrook and installed in the fiver then added two more. Four batteries 480 amps. Yes they are $450 for two, but 10+ years of perfect service, is worth it to me as we dry camp more than plug in.

    What you really need to understand is that flooded cell batteries if you discharge them more than 50% you shortening their life. After using a VOM to check batteries I installed a Trimetric battery meter. Just got back from a week on the beach. Dry camped and with solar and inverter never started the generator.
  • Purchased two GC2 batteries from Costco back in Feb 2019. Been working great. Just put a 65a load on them for 80 min. as a test a couple of days ago. Voltage was 12.25v at the end of the test. Took about 3 hours to charge them to 90-95% with a 45a converter. No complaints.
  • cliffy49 wrote:
    Since Costco is about a mile and a half from the house they were my first choice. After reading the reviews for the Interstate GC2 I am not sure.
    Mine have a sticker that says 2/19. They are the lighter weight batteries that get the bad reviews. Ive been taking specific gravity notes since brand new. Mine are working fine, but i barely use them. Only been weekend camping 3 or 4 times. They dont even have 30 cycles on them. For a battery rated for 1000s.

    The graphs ive seen say they dont even reach full capacity until over 100 cycles. Good chance mine will die from age instead of cycling.

    I will know their entire life. Curious myself to see how it goes. I would say buy them for these reasons.

    1. Price is good
    2. Costco is close
    3. Guessing youre not a full time boondocker that will drain and charge the batteries daily?
  • Bought (4) 6 volt from them about 16 months ago. Doing as expected.

    Ad a watering system and keep them happy. Flow-Rite is one. On Amazon and some auto part stores.
  • Not all Interstate GC batteries are the same. If you Google Interstate Battery you will find a local dealer that you can buy the Interstate Industral battery from. Mine are 4 years old and still going strong.

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