The Stovebolt Site Forums The Shop Area The Electrical Bay charging a battery (basic question)

hello:
it was my first time using a sears battery charger to charge a regular car battery and i accidentally set the charge to "2amp automatic deep cycle" rather than "2amp automatic regular"
about midway through upon realizing my mistake i switched to "2amp automatic regular" did i cause some harm by charging a regular battery with deep cycle and/or switching mid way?
the battery was removed from the vehicle.
thank you

Unless the battery acid boiled out of the battery, I would think it is fine. 2 amps is pretty harmless. I have a battery charger that goes up to 80 amps- but you only leave it on long enough to start the car. Just use the battery.

Deep cycle batteries need a slightly slower charge rate, so the voltage is lower on that setting. 2 amps is a maintenence setting anyway, so you would need the 10 amp position or higher to recharge a dead battery. While it's possible to recharge a dead one with 2 amps, it will take a week or more. As long as the acid doesn't boil out of the cell caps or the battery gets too hot to touch, you're not overcharging. Immediately after starting, an alternator will have a charge rate of 60 amps or more, so a short surge of high current is not harmful. Just don't force a high charge rate into the battery for a long period of time.

If the cells are not sealed, you'll need a hydrometer to check the state of charge. Full-charge specific gravity is between 1.265 and 1.300. A dead battery will have a specific gravity of 1.100 or less, so check the specific gravity every hour until it tops out. At that point, further charging just boils the water away. NEVER add acid to a battery, only clean tap water. Distilled water is best, but anything suitable to drink is probably OK in a battery. Stay away from water with high mineral content, or water that's been stored in a metal container like a galvanized bucket, for instance.
Jerry

I use distapped water my self. You know, from dis tap here.

I use dat tap over dare.

Thanks for the advice:
The battery I am charging is 850cc and it was pretty dead. I put it on the sears charger at the 2amp automatic setting on Saturday 11/15 and as of tonight 11/20 the charger only reads 50% charged and that has not moved in the last 48 hrs. neither the battery or charger is overly hot and I notice nothing out of the ordinary other than a little acid smell.

This is my first time charging a battery and I have been told by others in the past that the 2amp setting will give the most efficient charge and that the 10amp charge could "fry" the battery, however the sears charger manual says it is OK to charge at 10 amps. Am I doing something wrong here? what is proper?

thank you

409,
turn the charger up to 10amps, It will not hurt a thing on a vehicle battery you wont fry it, I use 2amps for my motorcycle batteries an that is abought it.
Just keep an eye on it after ya turn it up ..check it in a few hrs. and see where the state of charge is when it gets in the 90% range unhook it.
If you are using this battery daily it should be good to go... if you are like me and my 52, its snowin here in PA an it wont see sunlight till spring then I suggest investing in a Battery maintainer...you can pick one for less than $50 I use one on my truck an love it ...got one for my Dad's Olds he keeps in the garage all winter an he fell in love with it also.
Tim

Here's another reason to keep a battery fully charged during cold weather- - - - -a dead one will freeze! Once a battery self-discharges enough to get down around the 1100 range on specific gravity, all the acid is in the plates, leaving nothing but water. If the garage is not heated, or the car is parked outside, the water will freeze and ruin the cell plates. Never let a discharged battery get exposed to freezing temperatures!
Jerry

further confusion--

i left the battery on the 2 amp automatic charge (where the battery should have stopped charging when full). in spite of the low 2amp setting i returned to check on the battery only to find the battery acid boiling out of the vent with heavy fumes.

i know the low 2 amp setting should be harmless so why did this happen? is it indicative of a bad battery or charger? i am just trying to understand the locic behind this.

thank you.

stovebolt409,

I don't know the details of your dilemma but do know that a battery will boil during charging. You said 'vent' so you must be working with a maintenance free battery.

A 2 amp charge rate should hardly be enough to boil the acid, plus your 'automatic' charger should have tapered down to where this wouldn't happen. If your battery is actually a sealed unit, it sounds like it may be no good now.

Was your little charger toggled to 'automatic' or 'maintenance free'. I have a small charger and the settings are a bit ambiguous.

Stuart

the charger was set to 2amp automatic, so you are correct that the charger should have shut off/tapered down at full charge. but even so i agree that 2amps should not be enough for a 850cca battery to boil acid out of the vent. anyway i did go to autozone and purchase a new battery but i am still curious as to why this happened. yes-sealed battery.

thanks

It seems really strange to have a battery boiling at 2 Amps. I would suspect the charger.

I agree, Ive left a motorcycle batt. over night on mine set at 2amp ...with no problems??..just wonder if the offending battery had a shorted plate to begin with ??
Tim

Batteries normally bubble slightly during charging, but 2 amps is a pretty low (harmless) charge rate. At 2 amps charge rate, you would see occasional bubbling. With a sealed battery, I don't think you would see much from the vent at a 2-amp rate. At higher charge rates, boiling and spewing indicates sulfated plates that may not recover with charging. The charge rate that causes vigorous boiling with sulfated plates depends on how 'entrenched' the sulfating is. A battery that has been standing dead for along time- several months- may not recover with charging, and would likely boil pretty vigorously at 15-20 amps charge rate. Charging voltage is another indicator of sulfated plates- for most any 12-volt battery, 15.5 volts (7.75 volts for a 6-volt) at any charge rate above a few amps of charging current indicates a sulfated condition. From your description, either you had a shorted cell, or the battery was badly sulfated. Without a voltmeter to watch during charging, and not without the battery, this is all speculation.

Harvester

this is kind of off subject but still in the spirit I have a battery i just bought in the spring and I forgot it in the car and i am unable to get it out til next spring. i worry that the battery is going to be worthless after the cold MN winter

If it freezes, which it probably will unless it's recharged occasionally, it will get damage to the plates and separators inside the cell groups. I saw one battery that sat in a junk farm tractor for over a year in all sorts of weather and still had enough power to crank the engine, but it was definitely the exception to the rule.
Jerry

ATTENTION!!!

With regard to a "frozen" battery: If you even so much as think you may have a frozen battery and you can check inside, pop ALL of the fill plugs. CAREFULLY (so you don't splash nuthin') stick a WOODEN skewer down in each hole. NEVER, NEVER STICK ANYTHING METAL INTO A BATTERY!

If the water is slushy or frozen, DO NOT ATTEMPT TO CHARGE OR USE THE BATTERY.

A frozen battery is ripe for an explosion with predictable results: An instantaneous drench with acid, battery parts all over creation, and everything within the range of your "OH HOLY @#&%$!" commentary on the event will be contaminated with acid. Acid is useful for destroying insulation, seat covers, clothing, hair, rubber tubing, paint and most metal. It works slowly enough on everything except eyes and skin, that you won't even notice the holes in your radiatior hoses until next summer, and even beyond that when the electrical shorts begin to appear after you have replaced the offending battery.

Frozen batteries are nobody's friend.

My wifes f**d exploder was being a pig last fall,let it sit till febuary.of course the batt froze.Took the batt inside for a couple of day's then charged it.Figured it would be shot,but it still is working.Never had that happen before!!The batt is about 5 years old now.