OT: 2 amp vs. 6 amp charging

[Uniguy]

What are the advantages/disadvantages? Does a battery hold a charge longer if charged w/2 amps, or does it just last longer lifewise? Boat died on me, just shy of the dock luckily, but it seemed like I sure lost my charge quick this time out. Thanks in advance for any insight.

 

[MotorradMike]

Lead acid batteries should be charged at a maximum of 10% of the amp/hour rating. 6A is way below that for what I suspect is a car battery in your boat. The nicest thing you can do is to put it on a battery tender which will bulk charge, float charge, then maintain with a trickle.

Batteries don't like over-charging or over-discharging.
I suspect this one is toast.

 

[CalG]

Charging batteries

If you have wet cells, not the "Gel Cell or "Glass Mat" style batteries, returning from dead flat, a charging amperage great enough to promote bubbling and circulation is a very good thing.

The electrolyte will stratify and change concentration with respect to the plates when the charge rate is too slow.

Once the battery is restored to over 80% capacity, a slower charge is beneficial.

You can just listen to a battery that is charging correctly. fizzzzz and burp, but not a boil.

 

[Mmfh]

One thing to remember, don't leave the battery in your boat over the winter. If you have the normal wet cell RV type battery powering that trolling motor, sitting over the winter without a battery tender will most times kill it.

Batteries do good over the winter if they are charged. If the battery is allowed to sit and go dead, and also sits in the cold over the winter, dead. The cells could and usually do, stratify. I think that is what its called when a layer developed over the cell.

Anyway, you said it isn't doing what it used to do. Probably have a dead cell, take to a battery place and have them check it for free. Sometimes you can bring batteries back by giving them a short burst of high amps, then coming back down to the 6 amps. Putting a load on the battery for a minute while rapid charging sometimes is helpful as well.

New battery, keep inside over the winter, or keep a battery minder hooked up to it.

Good Luck!

Mm

 

[JL Sargent]

bass pro has or had their xps I 5/5/5 charger on sale couple weeks ago. It is a very good charger/tender you might consider. interestingly this charger will desulfate the batteries every 21 days. It charges 3 banks @ 5 amps per. I also saw it on eBay.

Here is the one I bought but they sell various configurations of it.

http://www.basspro.com/Bass-Pro-Sho...y-Charger-XPS-iT-5/5/5/product/10224685/58453

 

[CalG]

Dead batteries "sulfate". That starts as soon as the the charge goes lower than about 70%. Sulfation bridges the plates with precipitate. Really bad.

The "stratification" or depletion I mentioned has to do with the electrolyte in a good battery.

There are many informative references on the web. search "Charging wet cell batteries" for a sampling.

 

[JL Sargent]

You might have boat motor problems too. Rectifiers in outboards can crap out, diodes shorting, etc. So you might have bigger fish to fry than the charger.

Also to be clearer, I'm using my charger for 1 cranking and 2 deep cycle batteries for my trolling motor. I have a regular habit of discharging them below 70%.

 

[gnorbury]

Dead batteries "sulfate". That starts as soon as the the charge goes lower than about 70%. Sulfation bridges the plates with precipitate. Really bad.

Whiskers are more commonly associated with NiCds. Sulfation of a lead-acid battery is hardening of the lead sulphate on the plates, which inhibits the chemical reaction that occurs during normal charging. i.e. lead sulphate + water + electricity => metallic lead + sulphuric acid.

Cell bridging in lead-acid batteries is often caused by plate erosion, which is when parts of the metallic plates fall off (during discharge) and collect at the bottom of the cells. When the debris gets high enough the cell shorts out. Deep cycle batteries have antimony added to the plates to harden the lead and resist erosion. They usually also have a larger "trash" area at the bottom so more material can fall off before it causes a problem.

In the OP's case, it's unclear to me whether we are talking about an electric trolling motor with dead batteries or an internal combustion engine with a failed charging system.

 

[Porschefix]

If the ends of the battery have any bulging evident it most likely has been frozen and that will sorely damage the charge holding ability also. FWIW

 

[Uniguy]

Me thinks...

...I got it figured it out now. Thanks for everyone's help.

 

[gnorbury]

...I got it figured it out now. Thanks for everyone's help.

Great news! So what did you find?

 

[gnorbury]

Lead acid batteries should be charged at a maximum of 10% of the amp/hour rating. 6A is way below that for what I suspect is a car battery in your boat. The nicest thing you can do is to put it on a battery tender which will bulk charge, float charge, then maintain with a trickle.

Batteries don't like over-charging or over-discharging.
I suspect this one is toast.

You can charge much higher than 10pct of C provided the charger is capable of regulating the charging current to limit maximum charging voltage.

 

[edwin dirnbeck]

HOW CAN ANYONE KNOW ?
A typical automotive battery Is a cheap throw away sealed unit.When they fail after 2 to 5 years they have very little value.Many people have well thought out theories of why they fail.I say that if you really HAD to know why batteries failed,you would need to dissasemble THOUSANDS of batteries from different manufacturers . WHO has done this? As for as I know there is no INSTITUTE FOR THE PREVENTION OF BATTERY FAILURE. I am sure some manufacturers have had early failures of THEIR products and have disasembled THEIR batteries in order to find the problems,but the problems of one brand would little relevence to other brands.You can find people to swear to ANY answer you want about batteries,from never set a battery on concrete to putting baking soda in batteries and about 20 different rejuvinaters.I think most people are well meaning But their good or bad experience is based on a one time phenoninum ,such as setting a perfectly good battery on the ground and 3 hours later it nerver works again.Here is my story,I have a battery in my mower that is 9 years old ,I have never cleaned the terminals or trickle charged it in the winter so I will never clean terminals or trickle charge any battery.Edwin

 

[Vernon Tuck]

The OP did not ask for a brand recommendation so I'm probably going off topic. But I just have to scream OPTIMA MARINE BATTERY! It's far and away the best battery I've ever owned.

Expensive. And worth every penny.

 

[dbsuthe]

HOW CAN ANYONE KNOW ?
A typical automotive battery Is a cheap throw away sealed unit.When they fail after 2 to 5 years they have very little value.Many people have well thought out theories of why they fail.I say that if you really HAD to know why batteries failed,you would need to dissasemble THOUSANDS of batteries from different manufacturers . WHO has done this?

Actually, it's quite easy to know. Science gives us a very clear view into what is happening in a battery. Everything that heppens in a battery can be measured and observed.

Lead-Acid batteries have been around for more than 100 years. The materials are so simple that people used to make their own in the late 19th and 20th centuries. The home made batteries powered early radios as well as other equipment necessary to early rural life.

Did you know that the phone system runs off batteries? Well, they use a huge bank of batteries in each central office to power the system during power outages and simply run off the batteries while they are charging. Companies like AT&T ( Western Electric and Bell Labs ) have done a huge amount of research to determine the optimal charge and discharge of lead acid batteries. A 1% improvement in charging efficiency represents a huge savings when you think of a nationwide phone network. All of their findings are well documented.

Batteries will last a long time with proper charging, discharging and maintenance. Industrial batteries at the phone company last 20 years or more. The battery in my car (with a solar trickle charger) lasted 10 years.

Dan

 

[S_W_Bausch]

It seems a forklift mechanic hasn't entered this conversation, else "equalizing charge" may have been mentioned.

Equalizing Charge For Stationary Batteries ? Battery University

Okay, back to the O.P.'s question, and what I found when attempting to charge a motorcycle battery at a "2 amp" setting. The voltage was less than 12 volts, if I recall, which is useless for charging a "12 volt" battery to full charge, which is (if we trust Wikipedia) 12.6 volts.

Automotive charging systems are (usually) at least 13.8 volts output.

If the charger puts out 12 volts, the best you could hope for is less than 50%.

Automotive battery - Wikipedia, the free encyclopedia

So, the O.P. needs to check the charger's output voltages before trusting the charger to be useful.

If the O.P. had a daily-use or weekly-use vehicle where a battery could be safely mounted and easily spliced into the charging system (cigarette lighter?), that would be a fail-safe way to ensure the battery's charge.

I have thought of this for my propane forklift's battery, but have never gotten around to it.

 

[JST]

Charging can be done at any rate that doesn't "boil" the battery by over-gassing it. Not going to be an issue at 2 or 6 A.

I'd recommend a 10A charger minimum..... unless you like to wait a long time. You can put on a low current "battery minder" to keep rarely used batteries charged up.

Did you know that the phone system runs off batteries? Well, they use a huge bank of batteries in each central office to power the system during power outages and simply run off the batteries while they are charging.

And they HATE them..... That's probably one reason for going optical fiber.... aside from other good reasons, fiber cannot provide power, so they no longer need the nominal 48V to run your phone.

It becomes your responsibility to provide power to your own phones. If power is out, maybe you can't call and tell the powerco... sucks to be you, I guess..

 

[sticks]

I 'shocked' quite a few NiCads using a chart/guide for time held (seconds) at voltages stepped above their ratings. They go bad sooner if stored with more than 1/4 charge. What happens is crystal accumulation that won't release a held charge and will shut down an auto-charger that sees resistance as a charge level. It's really kinda there, just locked up, & it's amazing how a few seconds of 'zap' can release or recover so much of it. (some do this crudely with a DC welder ) btw: All cells in a 'bundle' must be good or be replaced by spot-welding tabs to reassemble them, an option lost on a wet cell battery with even one 'dead' cell.

That everyone (but me) is going to LiIon batts I've moved recently to 'desulphating' lead-acid, lead-calcium, and AGM batteries. My home-brew gizmo has been prototyped and used with success by several others on a popular tractor forum. It consists of a single diode with load/voltage limiter (100w bulb) & fuse (1a) and uses household current partially rectified to produce a 27v AC pulse/component and a net (filtered) charging voltage in the upper 13v to lower 14v range.

Early trials have brought a weak 7 yr old (lead-calcium) mower batt back to '50% charge' (13.58v after a 24 hr rest) and restored its ability to crank my 22hp B&S-powered mower, even in <20^ temps. (I'm not done with this one yet.) There is a recycler nearby who sells 'restored' and re-labelled (theirs) group 24 etc for ~$30. Apparently, old batts are 'desulphated' (pulsed DC at ~2x voltage), rinsed with distilled water and re-filled with acid. General consensus is that a battery typically reclaims 1/2 or more of its original life cycle after this process. (I get ~10 yrs from a new or OEM car/truck batt, neighbor averaged 5 yrs for the last 3 $30 'Diamond' brand 'refurbs').

I won't try to make a case for such an inexact science as rejuvenating old batteries but will be glad to share info/links with any tinkerers that PM for references. This is very much a YMMV endeavor, but with good bits of info out there and some successes I'll be working on this thru' the summer.

 

[machinistrrt]

Search for "ideal charge curve". Batteries charge in three or four distinct stages, as mentioned earlier. Also, search for "desulphator". There are a few designs available, most use a high frequency, low current pulse to accomplish the process.

 

[dbsuthe]

Charging can be done at any rate that doesn't "boil" the battery by over-gassing it. Not going to be an issue at 2 or 6 A.

I'd recommend a 10A charger minimum..... unless you like to wait a long time. You can put on a low current "battery minder" to keep rarely used batteries charged up.



And they HATE them..... That's probably one reason for going optical fiber.... aside from other good reasons, fiber cannot provide power, so they no longer need the nominal 48V to run your phone.

It becomes your responsibility to provide power to your own phones. If power is out, maybe you can't call and tell the powerco... sucks to be you, I guess..

I hate to say it, but I disagree with most of this.

1) The first statement is over broad. A small motor cycle battery will boil quite well if an unregulated 6 amp charger is left hooked up for a long period of time. I've boiled a car battery dry with a 2 amp charger. It turned out that the charger was (more or less) constant current so it kept upping the voltage to maintain the current.

2) The amps really have to be set in combination with the battery size and the length of time that you will charge it. The 12 AH battery in my electric start generator will be damaged if I use such a high charge for more than a few minutes. If discharged half way I want a 2 amp charge for 3 to 4 hours. ( 2 * 3 = 6 amp hours which is 1/2 of the battery capacity)

3) The phone companies love fiber because copper wires required one pair of wires (there are exceptions) for each potential conversation. Add houses to a neighborhood and you have to bury more wire. The advent of faxes and computers destroyed all the careful planning for outside plant. The old 1:1 ratio of houses to phones went out the window. Lots of un-planned cable was installed in the early 90's .

4) Unless I have really missed something in the last 5 years, all consumer phones still expect to see 48 volts on the wire from the phone company. To change that design would break every phone in every home. The electric connection to your phone is to power the phone's fancy electronics or wireless transmitter. Phones are only allowed to draw a certain level of power from the phone line.

Other than that, I agree with you 100%.

Dan