How long to charge battery?

[Big Al1]

I just got a new battery and am having problems that I, an electrical engineer cannot figure out. I was using a 1.5amp charger/maintainer to charge my battery at all times it wasn’t in the water. After two years of this I noticed my battery would only last half as long so I got a new battery. New and old battery is a Walmart trolling motor battery, pretty small battery, can’t remember exact numbers. Anyway, my new battery wouldn’t charge. My charger is supposed to charge to I think 13.5V and then cut off. When the voltage would drop to under 13V it would cut back on. Worked great on old battery. New batter charges to like 12.3V and cuts off saying it is charged. So I got a new charger. Couldn’t find the same so I got a similar 2amp, I believe, that charges until it generates less than 0.5amps and then cuts of. The new battery would be completely discharged and the new charger would say it is charged up after 15 minutes. Go out on the water and the battery is dead in 5 minutes. So I busted out my 10 amp charger and charged for about 3 hours and went out last night. It ran the trolling motor for probably one hour continously and then died. It was reading 12V under load at first and then tapered down to 6V under load. This is only a 28lb trolling motor on a 14ft jon. I just charged it 10 hours last night and I know that would charge it enough so if it doesn’t last this times its got to be the battery, right? Or could it be the trolling motor? I was just wandering if anyone has had a similar experience. This is just frustrating.

 

[rickdb1boat]

Re: How long to charge battery?

Big Al1 <br /><br />I'd take the Battery back to Wallyworld and get another or better yet, get another one somewhere else. There was a post not too long ago about the quality(Or lack of) of Walmart Batteries. Personally, I've had pretty good luck with them. But my Son-in-law just replaced 2 deep cycle batteries from Walmart that were only a year old in his RV. Both were junk and they offered him basically nothing in the way of Pro-Rated rebate.<br /><br />Matter of fact, here's the link to the discussion:<br /><br /> web page

 

[Big Al1]

Re: How long to charge battery?

Yea, I should take it back. Even after 10hours of charging it still was taking 10amps. Isn’t it supposed to go down in the amount of amps it will take. The voltage got to 15V. I’m just wondering if my trolling motor may be going bad. It sounds fine and the prop spins smoothly with your hand. I used to get 2.5mph but now only 2.0mph, probably from the drop in voltage. If a new battery doesn’t fix, then it is the trolling motor.

 

[rickdb1boat]

Re: How long to charge battery?

When I charge mine using the 10 amp charger, it consistently drops to next to nothing Amps toward the end of the charge. Got to be the battery. Better to take it back now, rather than later..

 

[crab bait]

Re: How long to charge battery?

i can relate..!! it's a s o b,, i agree ... don't think it's the motor,, if'n it's a minni kota.. <br /><br />charger's are funny.. i have one ,,from start to finish,, the needle bounces/goes from one sweep to the other.. the whole time.. seems to charge ok but it's screwy anyhow..like a 'rythem keeper'..<br /><br />it's probably the battery.. <br /><br />somethin' has to be replaced.. for the-process-of-elimination to begin.. and guess the charger has...

 

[SlowlySinking]

Re: How long to charge battery?

Hi Big Al1, my vote goes for a bad battery, and you're right, the charge amperage should drop as it charges due to the internal battery resistance increasing. I had a similar problem with a so called float charger, what it did over a period of time was ruin the battery, I hooked up a 10 amp charger and in the morning I still saw a 10 amp charge rate, you could hardly touch the battery it was so hot, charger was a bit warm too. SO, I got to thinking, my car has never ruined a battery from overcharging, I just replaced the original 10 year old battery in the wifes car, so, I rigged a car alternator with an internal regulator to an old washing machine motor with a fan belt, solved the problem, battery gets fully charged and an amp meter shows end of charge cycle. It cost next to nothing, much cheaper than a first class charger.

 

[Solittle]

Re: How long to charge battery?

In addition to a charger you need a hydrometer. They are cheap and easy to read. You can have a battery what reads 12.5 volts and not last long at all. The hydrometer will tell you that.

 

[Boatist]

Re: How long to charge battery?

Big All<br />You may have a bad battery but you also have a charger problem if it is a automatic charger. I assume this is a deep cycle battery. You do not say what size but a group 27 can take over 10 hours to charge with a ten amp charger.<br /><br />You say after 10 hours the voltage got to 15 volts. Your charger should shut off before it reaches 15 volts, so either this is a manual charger which may not reduce the current as charges up or the voltage regulation is not working. Charger should not charge over 13.8 to 14.4 volts and for sure not over 14.8 volts.<br /><br />If this is a manual charger you need to turn off when it reaches 14.4 volts.

 

[JAZZedBW]

Re: How long to charge battery?

I do agree also. But what if you have a battery that is sitting from winter to charge up?<br /><br />I took it out of the boat and it wasn't sitting on the concrete it was in our basement where its warm and it was sitting on blocks becuase if it sits on concrete it will drain the battery. And covered it so nothing would hit the terminals. <br /><br />How long would you charge a battery after winter?<br /><br />JAZZ

 

[Stratosfied]

Re: How long to charge battery?

I have had the same trolling motor battery since Jan 97. (Voyager Deep Cycle). When I am at the camp, I hook up to a 6 amp charger each night and go out in the AM. When I get home, I hook up a Q-Beam spotlight to the battery and drain it out, then recharge. Works for me.

 

[crab bait]

Re: How long to charge battery?

it's funny ,,that how practices spread worldwide.. an people have firm belief that it's true & or it works.. <br /><br />i believe you'd be hardpressed to find a 'do it yourselfer' in the free world ( iraq excluded ) that doesn't believe that sittin' a battery on concrete drains it.. <br /><br />an article in POPULAR MECHANICS disproves it.. concrete has no affect on it all..!!<br /><br />the belief , probably stems from when batteries were in a wax cardboard shell.. <br /><br />but know what...??? <br /><br />i still throw down a scrap board first..<br /><br />what the heck,, it ain't hurtin nuthin'.. <br /><br />old supertitions are hard to break..

 

[rickdb1boat]

Re: How long to charge battery?

That's so true Crab Bait. I have read all the articles saying it does no harm to leave them sit on concrete, but I've been putting them on a shelf or piece of wood for so long, I just can't bring myself to throw it on the floor. Old habits are real hard to break.

 

[Ted S.]

Re: How long to charge battery?

I'm with boatist on this one. He's right about the deep cycle batteries. They need a much longer charge time to bring it up to full. I think it's because they have more or thicker plates. The advantage with these batteries is with a full charge, they take longer to discharge. The charger needs to have a manual setting and a deep cycle setting. 10 amps rate for 10 or more hours might bring it up to full but deep cycle batteries are funny....Give it a rest for a couple of hours and give it another 10 hours to be sure. I deal with a auto electric place in our area quite often with my work and they gave me this information when I bought new batteries for my golf cart.

 

[B_Eager]

Re: How long to charge battery?

Have you check for a worpped plate in the battery, Had this happen years back on a starting battery, if I charged it all night the amp gage would read high low but seemed to make no difference when I went to start the boat on the lake, but after motor warm up from two laps around the lake we would shut down to go water sking and the battery would not be even close to starting the boat, wait 20 min. and all was fine. After maney hours of testing I found during hard charge the plates would short and either cause a massive charge or no charge. Solution was put the battery in the truck and buy a new battery for the boat.

 

[Boatist]

Re: How long to charge battery?

JAZZedBW<br />All lead acid batteries self drain. Starting batteries need to be charged as least once a month. Charge until the voltage reaches 13.8 volts to 14.4 volts. If you have a good automatic charger then by this time current will drop to near zero. Starting batteries should never go below 50 percent of charges because of way the thin plates are made of a kind of spoung lead. Deep cycle batteries can go as low as 20 percent of charge without damage because they have fewer but thicker plates of solid lead. Still better to charge at least once a mounth.<br /><br />For my batteries I set up boat so can charge from front of boat from a battery charger or tow vehical so easy to charge without taking cover off or any real work. I charge once a month year round. I charge to 13.8 volts for conventional bateries (one you can add water too). I charge to 14.4 volts maintenace free batteries (Gel batteries or ones sealed that can not add water to) I have never had a battery that did not last as least 5 years on the boat.

 

[JAZZedBW]

Re: How long to charge battery?

Thank you, Boatist for the reply. I will do what you do to your batteries for my boat. Thank you!<br /><br />JAZZ

 

[427hawk]

Re: How long to charge battery?

i have had bolth good and bad luck with wal-mart batts. i have one in the truck that is about 3 years old and doing fine, the batts. in lawn tractors doing fine , the new one i bought for the boat, junk and took back , i am leary of of them

 

[roscoe]

Re: How long to charge battery?

All batteries must be stored in a dark place, definitely out of the sunlight. Thats why flashlight housings are not clear, and why they tell you to use a battery box on your boat. <br /><br />Just kidding.<br /><br />But on the concrete/wood thing: Back in the seventies, I read in atleast one "reputable" periodical that concrete was a no-no.<br /><br />We have proof that storage surface has no effect now. But many people were mis-informed and still are.