Did i ruin the batteries?

[jasin1]

How screwed am i? purchased 3 new group 31 batteries for my Boat a few weeks ago….I have my pier on a GFCI breaker and if we get a heavy rainstorm or someone is washing one of the boats and sprays the outlet by mistake i lose battery power on the pier…usually not an issue because i keep both of my battery switches off and all of the bilge pumps are wired direct to the battery but my boat stays pretty dry so thats not an issue…(left my engine room light on and the radio was playing down in the cabin) and left my starboard battery switch on which powers the starboard engine and house battery..was doing some work and forgot to turn everything off before i finished that day!…i usually check my breaker daily but didn’t yesterday or the day before so maybe two days off and walked down to the boat and batterys are dead.
house and starboard are 10.6 volts……irreversible damage?? i need the battery’s for when im overnighting on anchor and now dont know if i can trust them to hold a charge overnight.
Any battery gurus that can reassure me or should i just replace them now?..i do have a battery parallel switch and my generator starts off the port engine battery so i wont be stranded unless i forget to turn that port switch off while overnighting.

 

[Notanlines]

We had three batteries on the Fountain and had them run down badly a few times but we only depended on them for starting the engines. We did replace all three every two years, they always seemed to be in good shape. I would risk it.

 

[jasin1]

We had three batteries on the Fountain and had them run down badly a few times but we only depended on them for starting the engines. We did replace all three every two years, they always seemed to be in good shape. I would risk it.

yes i guess i will try them but mad at myself for the mistake…i guess i could try and stress test them on the boat but i only have a cheap amazon battery load tester…we use the battery’s overnight only if it’s cool out because i don’t like sleeping with the generator on so it’s just radio,lights and refrigerator and water pump and vacuflush…adds up pretty quick.
i’d like to use a lithium for the house battery or a 8d but not sure it would play well with the other battery’s and charger

If anyone knows a decent load tester that isn’t a arm and a leg i’d like to get one…could pull and have them tested at the auto parts store but what a pain getting them in and out of the boat
Also i see victron makes a battery saver that will disconnect the battery if it falls below a certain voltage but dont know how that would work on a three bank setup with a battery isolator …maybe you install one on each battery?

 

[flybouy]

I think you have 2 options.1. Take the batteries back to the store and tell them they were discharged when you installed the. Or 2. Give them a charge with a quality charger that has a routine to desulficate or "rejuvenate" the battery. I use a 10 Amp maintainer that I ordered from Amazon ( https://www.amazon.com/Automatic-Ma...c_cp_ppx_hzsearch_conn_dt_b_bia_item_1_t&th=1) that has worked very well for me.

 

[JRTJH]

OK, let's go through a few things first. I'd guess the batteries are GP31 "deep cycle batteries" ??? If so, they have thicker plates and won't warp and short out as easily. They are "new" and haven't got a history of previous deep discharges ???

As Marshall said, a good charge using a battery charger with a "repair/desulfate" cycle and let the batteries recharge fully. Then do a "test run" (for your own reassurance) and leave a few items on overnight (to simulate an overnight anchorage. If you have a good ammeter you can set the load, time the hours with that load and calculate the total amp drain over that length of time. That should tell you what you need to know to trust the batteries if they pass your test. As a "backup plan" like you said, just remember to shut down the port battery so you have generator starting capability to get you up and running if things go south. Another potential: Get a GP24 "marine deep cycle/cranking" battery, store it in the engine compartment as a backup to start the generator if everything else fails....

My "SWAG" would be that the batteries are OK if this is the only time they've been discharged. They weren't completely discharged for a prolonged time (maybe 24-36 hours) and they weren't subjected to freezing temps while discharged. A "repair/desulfate" cycle should be enough to keep them operating, especially if you have two "backup plans" (port battery for generator and a spare generator starting battery if that fails)...

As for the battery charger that Marshall posted on Amazon, I have one similar to the 20 amp choice on that page. It has everything the 10 amp model has plus it has a lithium charging profile as well. I'd look at that as a better choice, not because the 10 amp model won't work for you, but because if you're considering lithium batteries eventually, the 20 amp model will 'grow with you"....

 

[chuckster57]

DW’s 2013 town and country had a brand new battery. The fuel pump relay stuck “on” and the pump ran until the battery was completely discharged.

I replaced the relay ( another story) thought I was going to spend ANOTHER $200+ on a battery. My HF charger went into “reconditioning” and that battery is working like new now for the last 4 months.

All this to say, I would give them a try.

 

[jasin1]

I think you have 2 options.1. Take the batteries back to the store and tell them they were discharged when you installed the. Or 2. Give them a charge with a quality charger that has a routine to desulficate or "rejuvenate" the battery. I use a 10 Amp maintainer that I ordered from Amazon ( Amazon.com) that has worked very well for me.

good idea on the charger I think I’m gonna skip pulling the batteries for now as they are really tricky to get in the boxes

 

[jasin1]

Thanks for the reply

OK, let's go through a few things first. I'd guess the batteries are GP31 "deep cycle batteries" ??? If so, they have thicker plates and won't warp and short out as easily. They are "new" and haven't got a history of previous deep discharges ???

As Marshall said, a good charge using a battery charger with a "repair/desulfate" cycle and let the batteries recharge fully. Then do a "test run" (for your own reassurance) and leave a few items on overnight (to simulate an overnight anchorage. If you have a good ammeter you can set the load, time the hours with that load and calculate the total amp drain over that length of time. That should tell you what you need to know to trust the batteries if they pass your test. As a "backup plan" like you said, just remember to shut down the port battery so you have generator starting capability to get you up and running if things go south. Another potential: Get a GP24 "marine deep cycle/cranking" battery, store it in the engine compartment as a backup to start the generator if everything else fails....

My "SWAG" would be that the batteries are OK if this is the only time they've been discharged. They weren't completely discharged for a prolonged time (maybe 24-36 hours) and they weren't subjected to freezing temps while discharged. A "repair/desulfate" cycle should be enough to keep them operating, especially if you have two "backup plans" (port battery for generator and a spare generator starting battery if that fails)...

As for the battery charger that Marshall posted on Amazon, I have one similar to the 20 amp choice on that page. It has everything the 10 amp model has plus it has a lithium charging profile as well. I'd look at that as a better choice, not because the 10 amp model won't work for you, but because if you're considering lithium batteries eventually, the 20 amp model will 'grow with you"....

Funny you should mention the extra battery… I started carrying one in the engine room about five years ago when I got the fifth wheel…I carried it as a spare when camping and put in the boat when we went for longer trips.. stopped doing that about two years ago when I stuck the battery in my old tractor one day and guess I just got out of the habit. Well I appreciate all the suggestions. I never gave much thought about batteries til I joined this forum

 

[Bandit12]

For a good charger/maintainer with a reconditioning feature, look at a CTEK. I have one I use for my HF Predator 3500 generator. I had the genny in storage for over a year and wasn't able to plug it in. When We moved into the house, I brought the genny home, tried starting it with the electric start, not even a click. I hooked up the CTEK, put it in recondition mode and let it do its thing. We went camping over Memorial weekend and used the genny several times and it fired right off every time.

 

[flybouy]

Thanks for the reply

Funny you should mention the extra battery… I started carrying one in the engine room about five years ago when I got the fifth wheel…I carried it as a spare when camping and put in the boat when we went for longer trips.. stopped doing that about two years ago when I stuck the battery in my old tractor one day and guess I just got out of the habit. Well I appreciate all the suggestions. I never gave much thought about batteries til I joined this forum

I don't know how your boat is set up but this got me knocking some cobwebs off the crowsnest and I remember ours. It was a 30' SeaRay with twin gas engins and a Onan genetic. It had 3 batteries and 3 battery disconnect switch.

We spent many, many weekends "on the hook" all over the Chesapeake Bay and it's tributaries "gunk holes". This was back in the '90s, before led lights, lithium batteries, or other energy efficient devices of today. I kept the boat at Gunpowder Cove Marina so it was connected to shore power and the batteries were always charged.

When we were heading out I had a routine. First disconnect the shore cable and stow it in the doc box. Then I'd start the generator and turn on the air-conditioner to put it under load. My thinking was that if there was an issue with the genset I would know that before heading out. It wasn't a waste of fuel (couldn't even notice a change in the 120 gal tank), but a good practice to exercise it weekly thru the summer months. In the sweltering months I'd let it run until we got out of the no wake area and get up to speed.

When at anchor, I would set the battery switch from "all" to "battery 3" which was the "house/genset" battery IIRC. Sometimes we would run the Gen in the am if we were going to cook breakfast, using the Magna grill over the side would always make scrambled eggs it the water was choppy.

So the point of this long winded reply is that doing this I never had a dead battery or a weak one that made for slow cranking. I made sure that the generator was in good order. If I had it, then I could start the engines. If the generator battery failed then I could bring the other 2 batteries on line if needed. Hope this makes sense.

 

[jasin1]

yeah i can start my generator and recharge but another consideration is what effect does low voltage have on things like my refrigerator …don’t know if it would damage the compressor or circuit board …just irritating that i possibly shortened the life of the batteries… gonna get a bigger house battery eventually