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Battery Charging question

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RedRaiderTooner

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Greetings all!

I have my boat stored in an RV garage with electricity. Both batteries had a full charge and the battery switch is off. Should I give both batteries a charge once a month to keep them full, or do you think it would be ok to charge after I pull it out of storage the end of February?

Not sure how much our mild texas weather would effect discharge.

Thanks!

Will
 
I went to my dealer yesterday and asked this exact question. Even though it is a trickle charger that shuts off automatically, they told me to unplug it and only charge it every 3 or 4 weeks. Their reasoning was that the charger could boil the battery by constantly turning on. They didn't think it was safe to leave it on all winter. I unplugged it yesterday, and I set a reminder on my iPhone to go back out to the boat in 3 weeks and plug it in.
 
Every battery has a diffrent discharge rate. Example traditional flooded batterys drain at a diffrent rate then Agm batterys abd the same is true for Gell and even Optimas have again a difffrent discharge rate. Its common for flooded led acid batterys to loose a charge over a long winter storage.

If you say you have access to power then Imo its a simple $50 fix and we can put a end to any argument weather to trickle charge or not.

A small 1-5 amp trickle "Battery Tender" charger will NOT boil or damage your battery. It has a automatic on off and float charge cycle and it SAFE to plug it in and forget about it.

Every boat I have has a On-board charger. With a small pig tail plug that allows me to just plug the boat in. this way Im sure i will have a New ready to go battery come spring time.

IMO a on board battey charger is a must for every boat.
 
Geewest said:
Every battery has a diffrent discharge rate. Example traditional flooded batterys drain at a diffrent rate then Agm batterys abd the same is true for Gell and even Optimas have again a difffrent discharge rate. Its common for flooded led acid batterys to loose a charge over a long winter storage.

If you say you have access to power then Imo its a simple $50 fix and we can put a end to any argument weather to trickle charge or not.

A small 1-5 amp trickle "Battery Tender" charger will NOT boil or damage your battery. It has a automatic on off and float charge cycle and it SAFE to plug it in and forget about it.

Every boat I have has a On-board charger. With a small pig tail plug that allows me to just plug the boat in. this way Im sure i will have a New ready to go battery come spring time.

IMO a on board battey charger is a must for every boat.
Click to expand...
Here is what I have in my boat. According to the write ups on it there shouldn't be a problem leaving it plugged in long term. I'm not sure why the dealer is hesitant to recommend that.

gallery_82_73_83416.jpg
 
Butchkid, I hope you just talked to the wrong guy at your dealer. They should be able to understand the "comes on when voltage is low and turns off when charged voltage is correct". A maintenance type charger, especially "battery tender" brands, as pointed out, will never boil a battery and I doubt a regular maintenance type will either.

Like Geewest, I use Battery Tender models and have had great luck with them for at least 15 years. In this case I would go with the forum. Good luck, Steve
 
I too have had great success with battery tenders remained plugged in all winter. I own 5 of them for all my toys and have never had a battery fail prematurely. (knock on wood)
 
I was told one time by a Delco Rep. that on deep cycle batteries.You where better off to let them completely discharge during storage.He explained if you did not the battery over a period of time would not hold full charge.
 
Turns out I have a miscalibrated voltmeter, so I deleted my original post that was here.
 
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Traditional deep cycle batterys flooded batterys dont do well with repeted full discharges these are discharges that are over 80% of the batterys storage.

A normal battery that you have in your car is called a SLI battery stands for starting , lighting . Ignition, these batterys have high cranking amps and are Made to only be dischargerd 20 to 30% example you crank over your car turn on the headlights and then your alternator starts charging the battery back up, now if you take a SLI battery and discharge it all the way mite than 3 or 4 times you have pretty much junked the battery,

IMO even deep cycles take a beeting when you run them all the way down over and over. My best luck with batterys is, keeping them hooked to a smart charger when ever possable.

I have 3 "92" amp hr deep cycle marine batterys in our 2275 r and when ever possable i plug the boat in. This keeps the batterys toped off at all times. Quality agm Batterys are a few hundred dollars each. A smart charger is only $100 or so. If you spend a bit on a smart charger your protecting your investment ( batterys) and more important your avoiding the hassel of a dead battery.

Btw i have Never heard that you should run down your batterys to keep them in good shape.

But it makes sence that a battery sales person told you that you should do this . This way you end up buying a new set of batterys every other year.
 
I too have a "smart" Dual-bank charger installed with 2 batteries in my boat. I have a waterproof plug mounted in the transom for the extension cord. Very convenient!!!

I try to keep the charger plugged in as much as possible during storage.
 
The Battery Tender Junior topped off the battery in 15 hours (after battery was off the boat for 2.5 months).

I remeasured, and still get 10 volts. Time for a new meter...

UPDATE: I tested a vehicle battery with the same meter. It showed 10 volts too. Meter going in the trash.
 
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Recomendation is to fully charge batterie OCV@ 13.6-14.2 before stoage then disconnect. They say batterie tender not recommended.The more i read a lot of it depends on personal preferance.
 
Have done some testing on my AGM battery's. I topped them off and did a voltage test. The best way to test is to fully charge your battery. Then let it rest or equalized after about 20 min's to 1 hr your battery should the be equalized. This is when you should test the battery's voltage. It Should be 12.6 or 12.7 that's a full battery.

My test was to see how long my battery's held full voltage.

They held the 12.7 for almost 2 months.

Do a test see if you boat has a voltage draw before you put it away for the winter. That way if your not going to install a battery tender you know your battery is not getting drained.
 
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OK I will jump in here. Having been a diesel tech for the last 20 years and having had battery classes I will keep it very short as I could type out many paragraphs and really muddy the water.

Deep cycle batteries have heavier lead plates in them which is why they are best suited for marine application because they CAN handle many many deep discharges and they stay good because as you all know a battery heats up when it charges. What kills standard batteries when deep discharging and fast recharge is that the plates warp and can contact and short out or just pull out of the bed they are mounted in. Where as the heavier plates in a marine or deep cycle are designed to handle the heat from faster charge and not warp the plates. The main reason for a trickle charger or battery tender is to keep the battery active inside to prevent scale build up on the plates which reduces the life and power of the battery. Over time on a battery that is inactive scale builds up on the plates and when the battery is put to use the scale will sluff off and accumulate in the bottom and if enough is deposited it to can create a contact path between 2 plates causing them to short out as well.

So in short if you want maximum life from a battery it is best to have a tender on it if not in use for more than a few days at a time even if its just a half an amp charger just something to keep it alive so to speak.

Hopefully you understand some of this. Or did I muddy the already murky waters even more?
 
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Very good explanation Bill, i would emphasize that it's the activity within the battery that keeps it alive, and that a discharged battery will freeze and ruin it, for those in cold climates. Well done ;)
 
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