Dead batteries

HUNTHARD

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On Sunday 11/21 boat was brought to local marina to be hauled. Boat wasn't plugged into shore power for about 5 days. I have 50 amp service over the winter and the boat is always plugged in. 5 days after being hauled the marina tells me my 4 - 8D batteries are dead.
Everything was turned off but battery switches weren't. All batteries are 3 to 5 years old. The ones I replaced were 10 to 12 years old. I guess the few questions I have is what would make them drain so fast with everything off and can they be brought back to life? I have a few trickle charges I am going to put On each pair tonight. My electronics guy said 4 to 5 years is the life expectancy. They have had charger / heated engine room over winter theirs entire lives, I find it hard to believe they were dead all season and only shore power or generator were keeping the, alive. I think ones of the 8D’s I replaced 3 or 4 years ago had the date of 2005 on it.

Thanks
 
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leaky

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That sounds like you have some type of draw, but by each pair you are saying there 2 pairs of paralleled batteries? You probably know this of course, but batteries in parallel can compete - basically they push charge back/forth infinitely and the inefficiencies of moving charge eventually kills them, batteries of the same type do this to a less severe degree where they should not die in 5 days but it might be a factor, basically in that situation if one batteries goes south then both do.

To have 4 batteries that are < 5 years old all jut shit the bed, no I don't buy it's a problem with the batteries unless they are out of water, or something really bad is happening to them during charging, but it does only take 2 if there are 2 pairs in parallel. To get down the the bottom of it you may need to experiment a little, ie remove the lead that parrllels them, trickle charge independently, check results, hook the parrallel lead back up and check results, etc.. etc..

Or it could just be a draw - when you say switches were left on, are all 4 batteries on the same circuit where it only takes one device to kill all 4? By turning the switches off you will isolate a draw as a problem, assuming there is nothing directly wired. Something like a stuck float switch is great for this type of thing, ie if a battery switch puts all 4 batteries on same circuit, a bilge pump hooked to one battery therefore has access to all 4.
 

aegus15

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I would try to bring them back , had a similar experience with a 1 year old 8D battery, still not sure why it drain , my trickle charger would not recharge the battery, ( 48 hours ) …brought it to interstate battery ( Freetown MA) where I bought it and was told it needed to be ZAPPED and a trickle charger would not do it.( ( high amp Zap??? ) not sure what they did, but 24 hours later battery was back and 2 years later no issues yet …….it is worth a shot , these are not cheap as you know . These batteries are not that old ( 3/4 years ) and life expectancy should be 7 to 8 years , I was told .
 

Genius

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what type of batteries? Lead acid or AGM? Throw the trickle charger out. A HD charger will take a while to charge 4, 8D batteries.
 

aegus15

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Mine was lead acid ….. as I said ,trickle did not work , needed a high amp charge ….
 

WoundUpMarine

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Brooksie

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Test for parasitic draw, it sounds like something is drawing current w/o you knowing it. Contrary to what you mention, storing your batteries in a heated space shortens their life, leaving a charger on them all the time, and connecting batteries in parallel also can shorten their life.
Once you get them charged again, just put a test light (12v bulb) across the battery switch terminals with everything turned off including the battery switch. If it glows, even dimly, you have a current draw. Then start disconnecting things until the bulb goes out. You are looking for a small draw so a small bulb or or multi-meter would be best. Many items have a small standby draw and may add up.
If you have old or failing battey permanently connected in parallel with another newer battery one will drag down the other except under charging conditions thus hiding the problem until you are not charging. Additionally, when you are charging, the bad/older battery can cause overcharge in the newer/better battery.
Being on a dock with a charger covers up a multitude of sins which are apparent right away on a moored boat.
 
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HUNTHARD

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Thanks for all the replies, they are batteries that you add water. Had two little trickle chargers for each pair over night and boat had power this morning. Now that we got everything powered up we will check the water levels and start to trouble shooting the draw. My guess is a bilge pump somewhere. Thanks again I was happy not to have to lug the huge charger Down there!
 

Genius

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Very important you check the water level before charging. There is no way trickle chargers have fully charged a bank that size. Properly anyway.
 

Brooksie

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Very important you check the water level before charging. There is no way trickle chargers have fully charged a bank that size. Properly anyway.
What genius said. Get a hydrometer for 5-7 bucks at Advance or Autozone. If you decided they were charged with a volt meter, you were just measuring "surface charge". The surface charge can be removed ideally by waiting 24 hrs w/o charging or discharging or by hitting the starter for 30 seconds.
 

Genius

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Another word of caution is; charging creates hydrogen gas. Make sure its ventilated somewhat, IDK if you are shrink-wrapped yet.
 

traditions

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I was always told to never leave battery switch on both. Use both to start ,and switch to 1 battery after. A bad battery will draw down the good one. And if you have problems, ou will still have the other battery charged. Works for me. I usually get 7 years or better out of Interstates.
 

cb34

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Bring the batteries up to full charge. Then disconnect them and see over time If they hold the charge with no load
 

Brooksie

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I was always told to never leave battery switch on both. Use both to start ,and switch to 1 battery after. A bad battery will draw down the good one. And if you have problems, ou will still have the other battery charged. Works for me. I usually get 7 years or better out of Interstates.
True, he has 4-8D's so they may be permanently paralleled 2 & 2 not the best way to go especially if you have old and new paralleled. I see no problem starting on both especially in winter but don't leave on both.
I think, when discussing batteries, first we need to know if the person is in a slip & and on a charger vs: on a mooring. Two different worlds IMO
 

traditions

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True, he has 4-8D's so they may be permanently paralleled 2 & 2 not the best way to go especially if you have old and new paralleled. I see no problem starting on both especially in winter but don't leave on both.
I think, when discussing batteries, first we need to know if the person is in a slip & and on a charger vs: on a mooring. Two different worlds IMO
I always turn off the battery switch when I leave the boat. I have two pumps wired direct o the battery, and they are up a bit in the bilge, so they never come on , unless there was a problem .On my novi, I had a problem with a batter6 going down, and I load tested it after a good charge, and it tested out good, but would be dead after a day fishing. I chased it around, and swithed the cables around, and finaly replaced it, and the problem went away. I never really understood what was wrong, must have been a bad battery
 

leaky

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I always turn off the battery switch when I leave the boat. I have two pumps wired direct o the battery, and they are up a bit in the bilge, so they never come on , unless there was a problem .On my novi, I had a problem with a batter6 going down, and I load tested it after a good charge, and it tested out good, but would be dead after a day fishing. I chased it around, and swithed the cables around, and finaly replaced it, and the problem went away. I never really understood what was wrong, must have been a bad battery

That's how I do it as well - never leave anything on thats not needed.

On the bilge pumps and such, I come off the direct battery leads somewhere before before the switches but not actually at the battery, ie a power lug, and I put a breaker followed by a small fuse panel. That feeds bilge pumps, chargers, battery combiners/auto-charging-relays, and anything I want always on. Then I can minimize connections at the battery while also having a shut off for all that stuff if I want via the breaker, and straight forward protection via the fuse panel as well. One of those setups per battery.
 

leaky

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Thats a good way to do it. I just run a line to the battery , which has a fuse and a push pull switch, so I can shut it off when I want .

I also like those 3 position push/pull switches, I found a slightly nicer way I think I will do it in the new boat with these 2 gang switch panels (ie one per pump, one switch forces pump on, one auto) but the push pull for me was always simple and intuitive - and a freak out moment you just pull them out all the way to make sure it's on.

All depends how much stuff you got going on and where batteries are located as far as if you want the added structure/cost. Start adding 12 volt refrigerators, leads for memory on the stereo, courtesy lights you want to turn on as you enter the boat to even see the battery switches, starts getting messy with inline fuses. 2 batteries with a 1/2/both/off and a boat on a mooring without an onboard charger charger, nah don't need it, cleaner to skip it.
 

Dave588

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I was always told to never leave battery switch on both. Use both to start ,and switch to 1 battery after. A bad battery will draw down the good one. And if you have problems, ou will still have the other battery charged. Works for me. I usually get 7 years or better out of Interstates.
Interstates are good batteries made by johnson controls. Thats what i usually look for.
 

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