[slumlord]

I got a new dry charged battery, and as per the instructions, I added the acid and let it sit. The instructions called for it to sit for at least an hour, but I let it set for three hours. Before charging it, the battery was at 12,57 volts.

Because of that, I only charged it for two hours and it read over thirteen. Even though the charger did not indicate full charge, I stopped charging it. After sitting overnight, the battery was at 12.77 or so.

I now wish that I had checked to see if it would crank a motorcycle before charging it just because I am curious about things like this.

Any comment from the battery experts?

 

[WintrSol]

Nope: http://www.autoshop101.com/trainmodules/batteries/105.html

 

[wadenelson]

Battery Chemistry Lesson

As a battery discharges, the surface of the lead oxide plates is reduced to lead sulfate as they release electrons.. The sulfuric acid in the electrolyte combines with the lead, releasing the oxide (oxygen). The electrolyte becomes more and more water and less and less sulfuric acid. The specific gravity of the electrolyte goes up or down, I can't remember which.

H2S04 + Pb02 --> PbS04 + H20 + e- (discharge)

PbsS04 + H20 + e- ---> Pb02 + H2S04 (charge)

Charging is just the opposite, by supplying an electron the Lead Sulfate is OXIDIZED (rusted!) to Lead Dioxide (Pb02) releasing a sulfate molecule which combines with the hydrogen and becomes sulfuric acid.

(It's fair to note that it's not a 100% efficient reaction, SOME hydrogen and oxygen "bubbles or boils, trouble and toils" its way out of solution which is why batteries have to be vented...and can sometimes explode --- while charging.)

It's also worth noting that if you put 100 Amp-hours into charging a lead-acid battery, on a GOOD DAY you might get 20 usable Amp-hours back OUT of same battery, which is why storing power in batteries is a losing game. (Why? because a battery has internal resistance, and MANY of those "lost" 80 Amp-hours simply went to warming up the battery, it's case, electrolyte, plates, surrounding environment.... just like a toaster, a batterh acts like a resistance heater as well as an energy storage device)

So you take a brand new battery, with lead / lead oxide plates which have never even tasted sulfur, and all the sulfuric acid is in the electrolyte you just poured into it, it's "born" 100% charged.

Oh sure, you can top it up with a charger, and battery mfr's often suggest that, but if it's already 12.6 or above...you're not accomplishing much. Just putting a "surface charge" on an already charged battery.

Mind you a battery manufacturer COULD ship you a brand new battery with already sulfated plates, you'd fill it up with distilled WATER, and THEN charge it rather than shipping caustic sulfuric acid....

What's MORE interesting to me, in the area of "self charging" is if you leave your lights on and come back to a flat battery, if you turn everything off and leave it all alone for 10-30 minutes you'll OFTEN regain enough charge to crank the motor -- once!

 

[Luvs2Play]

Batteries are charged before being shipped, all they need is to add the electrolyte. Should say that in the literature that came with the battery. They do recommend topping off the charge before using, but I have never done that and have never had a problem with not doing that.

 

[WintrSol]

For longest life, though, a 'dry charge' battery should be fully charged before first use; for MC batteries, a Battery Tender, especially a 1.5A one, is one of the best ways to do this.

 

[SgtSlag]

Follow the directions included with each battery. They vary, somewhat, from each maker. For the longest battery life, follow their included directions, to the letter. Cheers!

 

[slumlord]

For longest life, though, a 'dry charge' battery should be fully charged before first use; for MC batteries, a Battery Tender, especially a 1.5A one, is one of the best ways to do this.

Thanks for all the replies. I have a Shumacher 1.5 amp [automatic] from Wally World, but I am not confident that it is as good as a Battery Tender. Because the battery instructions called for a charge rate of .5 to .75 amps, I let it charge for an hour at a time and then rest for an hour The surface charge off this thing left overnight is ofttimes 13.5 or better, so that is the best I can do with what I have.

The link in post 2 by Wintersol is really thorough and with all the discussion that goes on around here about batteries and people wanting as a first step to change out expensive charging system components, the link and a explanation of how to evaluate whether or not a battery is beyond its usefulness might be appropriate as a sticky. I have found that batteries will last less than a year when they test 12.4 or so on the bike[ridden that day] after resting overnight.

 

[Porky]

The chemical reaction that takes place when the electrolyte is added charges the battery--they aren't pre-charged because they can't be.

Dry cell batteries come pre-charged.

Sam:coffeescreen:

 

[wadenelson]

Gosh, I guess a lot of folks just don't understand --- or didn't read what I wrote.

If a battery's lead plates are covered in oxide, the battery is charged. If the lead plates are covered in sulfate, the battery is uncharged.

Batteries get SHIPPED from the factory with the lead plates already oxidized --- covered in lead oxide.

Putting a charger on it won't accomplish ANYTHING. There is simply no lead sulfate on the plates to convert BACK to lead oxide through reduction --- adding an electron. Any sulfur is in the Sulfuric acid (electrolyte) you just added.

All you're doing is heating the battery, since, without any lead sulfate, there is nothing to charge, no chemical to reduce, no reaction to occur! (Applying a charging voltage to an already charged batttery simply creates heat)

While I'm normally a stickler for following mfr's instructions......

Other than perhaps stabilizing the battery, establishing some sort of equilibrium, making sure it doesn't leak, .... charging a brand new battery THAT IS ALREADY SHOWING 12.6 VOLTS OR ABOVE is a complete and total waste of time. Put it on the bike and go ride, for Pete's sake!

 

[OldDeadeye]

Gosh, I guess you being on so many ignore lists has something to do with that.

 

[Eye_m_no_angel]

Wade's back?

 

[hogcowboy]

Gosh, I guess you being on so many ignore lists has something to do with that.

That was my thought as well.

 

[Unkle Krusty]

Yup

Wade's back?

Yup, and still acting like a left handed fermion, possibly a dark left handed fermion.

Unkle Crusty*

 

[slumlord]

Somehow I doubt that one can simply dump the acid in a dry charged battery and instantly have full voltage and full charge. There is a way to find out, however. Buy a new battery and add the acid and check the voltage every five minutes. The voltage will either trend up as the chemical reaction occurs with the plates, or it will go down. Maybe it will stay the same. The next time I buy a new battery, I intend to do just that and report back to this thread.

Charging produces heat and will warp the plates of a battery if done to excess. That is why deep cycle batteries have thicker plates to guard against that. I am not sure how much my bike alternator puts out to charge the battery, but it seems to me that the engineers who write the instructions specify procedure and charging rate to either provide the consumer with a long life product or to cover themselves from liability when some guy hooks up his Binford 6200 Mega Amp and puts it on Boost and grunts like Tim the Tool Man Taylor

 

[Luvs2Play]

Somehow I doubt that one can simply dump the acid in a dry charged battery and instantly have full voltage and full charge. There is a way to find out, however. Buy a new battery and add the acid and check the voltage every five minutes. The voltage will either trend up as the chemical reaction occurs with the plates, or it will go down. Maybe it will stay the same. The next time I buy a new battery, I intend to do just that and report back to this thread.

Charging produces heat and will warp the plates of a battery if done to excess. That is why deep cycle batteries have thicker plates to guard against that. I am not sure how much my bike alternator puts out to charge the battery, but it seems to me that the engineers who write the instructions specify procedure and charging rate to either provide the consumer with a long life product or to cover themselves from liability when some guy hooks up his Binford 6200 Mega Amp and puts it on Boost and grunts like Tim the Tool Man Taylor

You are in for a surprise, new lead acid batteries don't need charged and will start your bike as soon as they are filled. Even if they have been sitting on the shelf for a year before being filled.

 

[hogcowboy]

^^^^ Yep, what he said. Last one I did was in the parking lot about 5 years ago. Filled it up and by the time I finally got the old one out and the new one in, it was nearly hot to touch even. By the time everything was buttoned up and I returned the old battery the bike fired right up and I was off for a 60 mile ride. Sold that bike 2 years ago and it was still doing fine.

 

[slumlord]

That's good to know. That could get one out of a bind when on a trip.

 

[hogcowboy]

Well it was right around 2 1/2 hours. I was very tired to start with so was taking my sweet time. But I do bet it would have cranked after 30 minutes. That's when I noticed it getting warm anyway. I had moved the bike under a nice shade tree out in the middle of the parking lot and made several trips back into the store.

 

[Oldman47]

My own experiences with "dry charged" batteries is that they are ready to go as soon as I pour in the acid. It has worked that way on my bikes and my cages.