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wgriswold's avatar
wgriswold
Explorer
May 31, 2017

Testing 6V Batteries

While chasing down a charging problem with my truck last fall I had my two 6V in series batteries load tested at an auto parts store. They tested bad and Costco replaced them since they were about 8 months old. Yesterday I had the new batteries load tested again and the new ones failed. Costco again replaced them.

It seems unlikely that the batteries should fail twice in less than a year. Does load testing work on 6V deep cycle GC batteries? The kid doing the testing knew less than I did and I don't know much about testing batteries. We chose to use the setting for marine batteries since we figured that was as close as we could get to GC batteries. They also failed at the setting for regular starting batteries.

15 Replies

  • Bottom line is that if they don't power anything after charging them, they need to be replaced. I'd suggest you find the source of the draw that is killing the batteries or you'll be destined to a life of battery replacement. It may also lead to a bad situation after setting up at camp.

    You do have a disconnect switch or remove a battery cable while in storage?

    In a previous career, I maintained a fleet of over 500 6V batteries. They are very forgiving and hard to kill. If you have to keep replacing them, there is either a constant draw or they are not being charged right. From your OP, it sounds like a mix of both but we don't know how you are using them and what they power. Sharing that may bring better results.
  • 12v tester or 6 volt? did you test them in series? Did he charge them at 14.8 volts for at least two hours before testing?

    What was the amp draw for the test? what was the cut-off voltage to fail?

    Not sure I know the answers but the method needs to be explained.
  • Ecomony of scale I guess. You have a test by an independent business saying battery is bad. Kid or no kid he tested for that company. You didn't influence the test. Costco says they accept the test that says battery is bad and won't test it themselves. You have no way to dispute test or force Costco to test. Certainly in my state you have done nothing wrong. You can lead the horse to water but you can't...
  • Lwiddis wrote:
    Seems like you have discovered a new battery goldmine. Not sure of the ethics but Costco is buying tit...hmmmm


    Yes, it is odd. I asked Costco to test them but they said they do not do that. They accepted the test from the auto parts store. I don't want to take advantage of Costco, thus my question about the test.
  • Seems like you have discovered a new battery goldmine. Not sure of the ethics but Costco is buying it....hmmmm