Troubleshooting issues with Dual-purpose battery

New boater here. Thanks in advance for any help!

My new-to-me 25' bowrider's been in the water for a week and it looks like there's no charge on the dual purpose battery (Duralast 27 DP-DL). I'm looking for advice on whether I should (a) charge the battery myself; (b) replace the battery; or (c) hire someone to troubleshoot the issues. Some quick comments/symptoms:

  • I don't know the age of the battery - I just bought the boat in Oct - but visually it looks great (pic below) and like it's been well taken care of.
  • The (very reputable) storage facility is supposed to check the battery before they launch it. I'm trying to confirm whether or not that happened - or what the reading might have been.
  • After launch, it took the boat out for 2 quick drives (1 hr total), and it seemed fine. I saw no warnings/lights indicating anything was off. And I definitely thought I turned off all electronics when leaving.
  • A couple of days ago, I couldn't get any power to any electronics or get the engine to start. The next day I confirmed with a multimeter that there was no charge to the battery.
  • With the battery switch on, the voltage reading was zero. With the battery switch off, it read 0.2V.

So I'm trying to figure out if I should assume it's just a bad battery and either charge it or replace it, or whether that voltage difference is big enough that I should assume there's a significant parasitic draw, and have someone else find the find/diagnose the problem (I'm not confident I could find the source of the problem).

Any recommendations?

Thanks in advance!



  • A discharged battery is not necessarily a bad battery. It just means that the battery has been drained. This is relatively normal if you do not have a charging source keeping your battery charged and the boat sits for a while. You need to keep your battery on a maintainer charger to ensure that it stays charged and ready to go. You should also monitor the battery electrolyte level to make sure it is at the proper level and is not low.

    Of course, turn off your battery switch when leaving the boat to help reduce parasitic loads that might drain your battery over time.

    Once the battery has been recharged, it can be tested at any West Marine store to ensure that it is still good and holding a charge properly.

    I always recommend taking a jump starter device with you, as it can save your day out on the water!

  • In my opinion, it is time to replace the batteries. Install Marine batteries and install an onboard charger to help out with charging needs!

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