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Battery Question

XafXaf Posts: 1,132 Officer
I have a sealed 12V marine deep cycle battery that I use for deep dropping with my electric reel.  Ninety nine + percent of the time it sits in my garage on a battery saver (smart trickle charger).  My question is,  "What should the life expectancy of the battery be under these conditions?"  I don't want to go offshore some day and find that the battery is dead and won't hold a charge.


  • The Cat's EyeThe Cat's Eye Posts: 1,741 Captain
    edited May 2022 #2
    Garages are not good places to store lead acid batteries. Battery life is reduced at higher temperatures. This holds true for ANY type of lead-acid battery, whether sealed, Gel, AGM, industrial or whatever.
    Some authorities say that for every 15 degrees above 77 degress F. battery life is cut in half.  

  • XafXaf Posts: 1,132 Officer
    I'm not too concerned about the heat in the garage.  I'm not sure why but my current garage gets warm but not hot even in the middle of August/September. The garage at my previous home would get so hot I could not stand to work in it even with fans blowing. 
  • The Cat's EyeThe Cat's Eye Posts: 1,741 Captain
    edited May 2022 #4
    My two car garage hits 90 plus degrees all summer long.  Probably due to the fact that my garage door faces south. If your garage door faces some other direction other then south it would be cooler then mine.  But the plus side of my garage facing south is that my roof covered patio faces north and is cooler for that reason then if it faced south. (Which is one of the reasons i choose my lot for building the house)
  • Kokosing LoverKokosing Lover Posts: 1,183 Officer
    My garage door faces north, and the interior temp punches right through 90 degrees every day of the summer.  It's also an unfinished garage with no insulation and no shade over the roof, which I think is the main driver for the high temps.
  • lemaymiamilemaymiami Posts: 4,909 Captain
    Two to three years is your battery's lifespan - longer than that can be achieved by careful maintenance.  As far as your garage is concerned you can also insulate the inside of a garage door (something I'm planning on doing when I replace my garage door this spring (double garage, east facing door...).  Back to your battery.. If in doubt place a proper charger on it the week before a planned trip (at least a six amp charger, a 10 amp would be quicker...) and if it doesn't charge up completely you're needing a replacement.  Whenever I keep a battery on my garage floor I always place it on a piece of wood -never on the concrete floor directly.  I was advised, many years ago that a battery can discharge into concrete, don't know if that's true but have never wanted to find out... 

    I've also considered a mini-split A/C unit just for my garage since it's my workshop as well as where my skiff sits and it does get cooking if I don't have the garage door and side door wide open when I'm working there (tying flies, making lures, building and repairing fishing rods, reels, etc.).  Add to that the much needed maintenance on my guide skiff (Use a boat hard and something always needs fixing...) and over the years I've often considered a stand alone A/C unit for my garage... just to keep it reasonable... 
    Tight Lines
    Bob LeMay
    (954) 435-5666
  • XafXaf Posts: 1,132 Officer
    edited May 2022 #7
    Lemay, I agree on the battery discharging through concrete.  After experimenting years ago I now store my battery on a short piece of  2" X 6".  I just completed a small kitchenette. bathroom and game room addition and added a mini-split unit. I am amazed how well it works.

    Back to the battery, it is already 4 - 5 years old and is still going strong, which is one reason I posed the original question.  I guess as long as it takes a charge and the battery conditioner indicates that it is good I'll continue using it.   

  • lemaymiamilemaymiami Posts: 4,909 Captain
    At that age your batt is doing great.   As much as I use and keep charging all of my batts I'm lucky to get three years out of them (standard wet cell batteries, 2- group 27 batts (for my trolling motor) and one group 24 - my starting and house battery... 
    Tight Lines
    Bob LeMay
    (954) 435-5666
  • The Cat's EyeThe Cat's Eye Posts: 1,741 Captain
    edited May 2022 #9
    By using a large window fan positioned on the floor at the propped open house door, i can lower the tempetature in my garage by ten degrees to about 80 degrees F in the summer months. i also made cardboard inserts to block the screened openings that are at the bottom of the garage door. I only do this if i need to work for an extended period of time in the summer months. Works even better at night.
  • TarponatorTarponator Posts: 20,467 AG
    edited May 2022 #10
    The following doesn't apply much to batteries, which seem to last only two or three seasons no matter what I do, but I thought I'd mention it anyway:

    You might consider a dehumidifier in your garages instead of an AC.

    It's not really the heat that causes problems, IMO, but rather the humidity in combination with the heat, and a dehumidifier is typically easier to install and cheaper to buy and run.

  • CaptjamesCaptjames Posts: 244 Deckhand
    Get a cheap load tester and load test the battery before going out. 
  • MissedMissed Posts: 749 Officer
    3 years is pretty much the life expectancy for a battery in FL.

    No idea about the lithium batteries, they are just pricey.
  • cortrcortr Posts: 538 Officer
    Agree that three years is the norm as far as battery life. Just replaced my 3 trolling motor and 1 cranking batteries 
  • Gr8LakerGr8Laker Posts: 109 Deckhand
    I've had my 2 Interstate batteries for 7 years, and they're still going strong. I don't abuse the boat and I keep the batteries clean and well ventilated. Always on a solar-powered trickle charger, too. ($19 at Harbor Freight)
  • Big MakBig Mak Posts: 6,470 Admiral
    A solar battery maintainer is a great way for the average boater to keep batteries working stronger on smaller boats for a longer life. 
  • cortrcortr Posts: 538 Officer
    Agree with Big Mak, solar chargers are great for maintaining battery. When fishing a long time with motor not running, solar will keep battery charged even if multiple electronics(GPS,stereo, power poles,etc) are being used at the same time.
  • LostconchLostconch Posts: 1,130 Officer
    I don't know where you get your batteries but the deep cycle batteries walmart sells are only guaranteed for 2 years
  • Docked WagesDocked Wages Posts: 3,167 Moderator
    edited June 2022 #18
    Battery life is typically designed to meet a certain number of life cycle charges.  A full life cycle is based on the depth of the discharge.  The use of a programable trickle charger (identify the battery chemistry and discharge level) greatly improves the life of your battery.  This will charge only the amount discharged then stop and some will go into a conditioning mode versus overcharging your battery which can be catastrophic. Therefore a battery designed for 500 life cycle charges may get 1500 life cycle charges through a charger that can identify the discharge depth.  Resulting in a 33% discharge recharged 3 times is only 1 lifecycle charge.  I had three Odyssey Extreme batteries in my Maverick on a Stealth 1 AC/DC charge combo, leaving it plugged in at all times.  I bought the boat with the batteries already installed (i.e. already used) in 2010 and replaced them in 2018. I did not use the boat much in the past five years due to having another boat, which distributed my life cycle across a longer period. Bottom line the battery life is directly tied to its recharge lifecycles and more often you charge in small cycles before full discharge the longer the battery will last. 
    Mark Wilson
    USCG 100t Master, Assist Tow, 200nm Coastal
    Marine Surveyor, SAMS, ABYC, IAMI, FMIU
    Wilson Yacht Survey, Inc. 
  • CaptjamesCaptjames Posts: 244 Deckhand
    Lithiums will go at least 2000 cycles, compared to 600 for agm, big difference in life expectancy.  They can also be run all of the way down to 10%, AGM's after 50% discharge the batteries get damaged and shorten lifespan faster.  Most lithiums have a 5 year free replacement warranty. They also last a lot longer per charge on a TM, 50% longer since they don't lose voltage as they discharge and draw more amps. 
  • flagoldflagold Posts: 1,608 Captain

    We had golf cart batteries on the Mischief we lived on and got 5 years out of them.  I attribute the lifespan to they had their own compartment away from engine heat and were sitting on the hull (cooled by water).
    Final Voyage Of Mischief:
    Zebco 33 ID Guide:
    Bridge/Jetty Rig: Any Depth Snag Free:
    Rebuild Grandpa's Zebco 33:
    Bomb Holes, Wrecks & Reefs ID & GPS#:
    Fish Attractor That Works: 
    Big Sheepshead With Snails:
  • MtgMamaMtgMama Posts: 137 Deckhand
    We just removed 3 Group 31 105 amp hour AGM deep cycle batteries and replaced with 36 lithium.. Been kept on triple bank noco auto charger , omly used 6 times down max 40 %.. $100 each.
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