Author Topic: Discharging Deep Cycle Batteries (Read 3524 times)

TimV · « **on:** May 04, 2005, 10:33:26 PM »

I have 2 large very heavy deep cycle trolling motor batteries one is a year old now and the other is 2 years old both have maybe 20 hours of use on them. Stored in garage where it does not freeze and were both charged before winter.

I am now discharging them both completely by having hooked a headlamp on each of them from a car. Will leave on headlamp all night long. This should flatten them .

Then I will put on a 2 amp deep cycle battery charger. I am told this is best thing to do to get maximum life out of a deep cycle battery.. Neither battery is a combo start/troll.... Let me know if I should not let them get that flat...Thanks Tim V

PS have been discharging for about 2 hours now and both seem very strong still

johnlm · « **Reply #1 on:** May 04, 2005, 04:38:37 PM »

If your looking for someone to stop you then I guess I will say - I would not discharge them that far. Im not sure where you heard the thing about discharging them fully then slow charging them. Ive never seen it help a lead acid battery to fully discharge it.

John

picmacmillan · « **Reply #2 on:** May 04, 2005, 04:38:56 PM »

dont discharge the battery completely, in fact dont discharge it more than 20%, if in fact you do discharge it 50%, you will have damaged your batteries, and they will not charge to their full potential again...look in my picture files and get my file on bateries.pdf..it has all kinds of information on how to treat your batteries, to get the most out of them......pickster

Norm · « **Reply #3 on:** May 04, 2005, 04:50:48 PM »

IMHO Stop! I am not an expert on batteries...

but this just doesn't sound right. I have heard

about discharging some type of batteries ...

maybe the old NiCads.

I have left my SLA battery over two winters

It is out in the shed I feel that as long as it is kept fully charged (Not Overcharged) this battery will Never freeze.

I make sure it never goes below 80% of full charge, in fact I doubt if it has ever got down

below 90% of full charge.

( :>) Norm.

Norm · « **Reply #4 on:** May 04, 2005, 04:55:32 PM »

In the time it took me to write my first reply

two others answered ahead of me. So I guess you

get the idea.

Norm.

Chiron · « **Reply #5 on:** May 04, 2005, 05:15:14 PM »

What he/they said, in Spades!

Lead/acid batteries ane NOT the same as the older NiCads. The only thing you get by completely discharging a Lead Acid battery is toxic scrap.

wooferhound · « **Reply #6 on:** May 04, 2005, 06:19:16 PM »

Here are a coupla links to an entirly large amount of information about batteries

http://uuhome.de/william.darden/carfaq.htm

http://www.uuhome.de/william.darden/batlinks.htm

nothing to lose · « **Reply #7 on:** May 05, 2005, 01:53:45 AM »

ACK, EEK

Was this advice from a battery sales person trying to up their sales quota for the month maybe??

I won't say it, everyone else has already.

If the batteries work to begin with a slow steady charge or pulse charging should be good to help revive them maybe to better performance if you want.

ACK, EEK on the total drain

I don't even do that with the shot 6V ones yet that only hold 4V!

ghurd · « **Reply #8 on:** May 05, 2005, 08:24:16 AM »

I, so that makes 2 of us, HAVE heard that too.

It is bunk. BS. Wives tale. Whatever.

It will cook the batteries.

For trolling motor use, charge them as soon as you get back.

The longer they spend low, the shorter they live.

Don't forget to check the water.

G-

Tyler883 · « **Reply #9 on:** May 05, 2005, 01:26:03 PM »

the best way to get maximum life out of a battery is to keep it indoors with a conituous conditioning charge, then never ever use it for any reason! LOL

RC in FL · « **Reply #10 on:** May 05, 2005, 06:56:14 PM »

Best thing for Lead Acid is a constant trickle charge at about 13.3 vdc. Keeps battery charged and not high enough rate to create much electrolyte water vaporization (bubbling).

Two primary things about inactive Lead Acid batteries.

Any discharge either from regular loading or self discharge creates lead sulphate on the plates. Initially it is like soft moss and easily reversed back to lead on plates and sulphuric acid in electrolyte by recharging. If left there for month(s)it hardens like tartar turning to plack on your teeth. The harded lead sulphate does not easily reconvert to original parts when you apply charge. Lead sulfate is an insulator, not good to have coating the plates.

Second item is stratification of electrolyte. Acid drops to bottom, water goes to top of battery. A moderate discharge for 30 mins (only about 5%-10% of capacity consumed. Discharged at about 20%-30% of A-H rating in amps, 25A for 100 A-H battery) and immediate recharge will mix things up. A procedure called equalization (controlled overcharge) can be used. It takes battery up to about 15 to 15.5 vdc for 30 mins to couple of hours depending on size and type of battery. This will mix up electrolyte and sometimes break loose lead sulphate. Battery will bubble like crazy with some hydrogen outgasing. Not a good method for sealed, maintance free type of battery.

sinclairbrett · « **Reply #11 on:** May 13, 2005, 09:05:39 AM »

The view i can give is like any thing treat them with respect and they will 1.help u when u need them most and 2. they will not bite u

( I have good experience of abusing batterys it cost me a lot of sight in the right eye thats why i respect them now)

TimV · « **Reply #12 on:** May 16, 2005, 05:05:24 PM »

Progress report: My gas motor starting battery seems to have come back and stays at full charge or at least what I think is by my chargers meter and will shut down and "charged" cvomes on almost immediatley. Same for my smaller trolling motor battery full deep cycle battery.

My newest and super large capcity full deep cycle trolling motor has not fully recharged yet but is still taking a slow trickle charge for several days now. I can not get the guage on the charger to go to "green" even by boosting it to 10 amps.It bubbles slowly. This battery weighs near 100 lbs.It was not totally dead when I went to shut the light off when discharging it after 10 hours hooked to a large headlight(posted earlier)

I broke my hydrometer aand will pick one up in morning and test all the batteries..maybe its not a total loss....Guess i wont do this again..lol TimV

ghurd · « **Reply #13 on:** May 16, 2005, 08:02:39 PM »

A 100# battery is going to take a while to trickle charge.

What is that? 250AH?

Maybe put the 10A to it for several hours,

then back to the trickle charge.

Either way it is going to take a while.

The ones that say 'charged'.

The starting battery, hook up a head light for an hour and see what it says.

The trolling battery, do it for 2 hours.

A bad battery can read 'full' after charging.

It is after some discharge when it shows up as bad.

An excessivly bubbling battery while trickle charging is a bad sign.

All the cells should read close to the same.

The more BBs a tester has the better.

Maybe I'm paranoid about boat batteries.

I get a new starting battery every year,

and test the deep cycles.

And I carry a full 12v 7AH.

At least my 'Coast Guard come help me please radio' will work on any of them.

Here by the Great Lakes people die because of bad batteries.

G-

TimV · « **Reply #14 on:** May 17, 2005, 05:09:46 AM »

Hi

I am lucky ..I am on south end of Lk Champlain in NY/VT where its only a 1/2 mile or less wide...so if we get a dead battery not a problem like it is for you folks on the really big water. Being from UP in Mich. I know exactly what you face on the big lakes.

use my batteries to push us through the weeds looking for that special place the fish went to....but we never seem to find it...Fish win 99.99% of the time....lol.

I had an uncle of an uncles uncle twice removed and added back again, who was a Great Lakes captain who had 4 wifes (all died in childbirth as story goes) and 36 children....(I think he must have some help while out on the water)

"A bad day of fishing is better than a good day at work."

ghurd · « **Reply #15 on:** May 18, 2005, 12:23:33 AM »

An old timer told me this...

My first wife died from eating poison mushrooms.

My second wife died from eating poison mushrooms.

My THIRD wife died from eating poison mushrooms.

But I can't get this one to eat mushrooms!

I'm getting geared up for our fly-in in Quebec.

Building a takedown pocket mill for the AAs, camcorder, sonar, etc.

Up to 70ma@12v, and 130ma@6v.

Not so great yet, but it is light and will fit in a big pocket.

Needs some parts made on-site, like hotdog stick type things.

It'll give me something to do when they want to stop for stuff like food.

They always want to do that.

Every-dang-day, I hear "But I'm Hunnngry" or "But it's Snooowing"...

She should have eaten before she married me!

Actually, she loves it too. I got a keeper.

G-

TimV · « **Reply #16 on:** May 18, 2005, 03:31:00 PM »

I hope you have really good bug repellent. With all this cool weather and rainy days I bet when it does decide to warm up.. them French speaking bugs and black flies will carry off a small horse.

Hard to find a "good woman" who likes fishing anymore.... I got a keeper also and she is willing to clean a fish or two on special occasions!!

Got a floating ball tester today. Going over tonight and check the big batteries charge.It was still taking a trickle this am and let it go at 10amps for 3 or 4 minutes but still did not kick off charger. TimV

ghurd · « **Reply #17 on:** May 19, 2005, 09:00:23 AM »

Only 100% DEET.

And we start burning those mosquito coils in an enclosed are a day before.

About 3 days of breathing that coil smoke and the bugs don't even notice you.

Not healthy, I'm SURE, but that is why the locals never get bother by bugs.

The stuff stays in your system, as far as the bugs can tell, for about 60 hours.

So have to remember to keep them burning, as it takes 3 days to get the effect again.

People who say that is a bad idea have never actually experianced the flys in late May or early June!

TimV · « **Reply #18 on:** May 20, 2005, 05:23:36 PM »

Being eaten by the 'little buggers" sure gives you a respect for them that never can be found in a persons backyard..Think of it as "paying your dues'Now enjoy that trip!

pyrocasto · « **Reply #19 on:** May 20, 2005, 10:02:54 PM »

The bugs were so bad one time camping at the beach, that the thrid night I needed sleep so bad we lit a bug coil in our tent and fell asleep. It cant be good to breath in "Raid" but it was the best sleep that trip. :-)

pyrocasto · « **Reply #20 on:** May 20, 2005, 10:05:12 PM »

I wouldnt trust your smart charger, but I would your multimeter. My smart charger shuts off and says full, but a few min later my batteries are down to 11 volts. I've been trickle charging them with 2 amps now for weeks, just moving around to each on. Mine are 160#(250AH).

TimV · « **Reply #21 on:** May 21, 2005, 08:55:15 PM »

I got a ball tester.Says all are overcharged.5 floaters! 4 is full chatge. But on a happy note the charger now indicates each is full charge. Will run the big one down for a couple hours and retest. I still have a week to trickle it if need be.

And speaking flying critters..I have a small(very small)poorly built camp(fishing schack)on Lk Champlain that is right on the water(right now at 98.5 feet above sea level its actually more like in the water... On a warm night and the windows all open I put on a long sleeve insulted underware shirt after bathing in OFF or some sort of insect repellent...And still spend more time "slapping and scratching"than I do sleeping.

This year I have a 10000 BTU AC to take with us and i will attemt to freeze the little buggers.

Wife thinks the electroic zapper does a number on them..but thats outside...Where are the bats when you need one.........

Less than a week till rest relaxation and F I S H I N G !! !! And more F I S H I N G

pyrocasto · « **Reply #22 on:** May 21, 2005, 09:19:42 PM »

I would suggest a bug net around the bed. works numbers.

Big All · « **Reply #23 on:** May 22, 2005, 10:00:13 AM »

For some fun 'round the campfire, get yourself a few of those electric tennis raquets.

You get a mini lights show and the evil grin of revenge.

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Author Topic: Discharging Deep Cycle Batteries (Read 3524 times)