Dang! Battery question

I have to haul a load of hogs tomorrow and want to take the good pickup. I haven't driven it in a week. Apparently, when I did I left the key on the accessory position and it was DEAD. I charged it a while and drove it to town. I still didn't think it was cranking fast enough so I put the 10 amp trickle on it - it pegged at 10 amps.

How much life does that take off of a battery? It is a year old. It was a surprise when it happened so I put a Walmart battery in it. I got a good one, but it wasn't an Interstate like I like.

I checked before I came in for lunch and it was down to a couple amps. I've managed to never do that on anything around here. That in itself is a miracle considering how many batteries there are on this farm. It still makes me mad, though.

A battery will never let you down until the moment you are really depending on it.

That would be normal for a 10 amp charger to peg with a near dead battery. Also, a 10 amp charger is not a trickle charge. It is a fairly high rate of charge for a battery that has been sitting dead for a few days. I always throw the volt meter on while charging to make sure voltage does not exceed normal fully charge volts which would be right near 14.5 volts. It probable did not exceed that voltage when first charging but a 10 amp charger will indeed exceed that when approaching full charge unless it is one of those automatic ones that always quit well before full charge had actually been obtained. If your battery did not freeze I doubt you hurt it or very little if at all in one week. Trickle chargers are to maintain a battery at full charge and not to recharge it as they will produce less than l ampere.

Hello Notjustair,

One year old battery going dead one time probably not a big deal. It should have plenty of life left. After charging and resting, voltage should be 12.6V @ 80 degrees F*. Any voltage reading has to be stated only after it is adjusted for ambient temperature. Sounds like you used an automatic charger. tapering off the charge to 2 amps means that, the battery got charged, and the charger did its job! all is well.

Guido.

My "good" truck, a 2005 F250, will go dead if it sits too long. With the 6.8 V-10, I don't drive it every day at these fuel prices. I mounted a battery maintainer under the hood and keep it plugged in during periods of inactivity.

I got in the habit of pulling the key out in my 04 Dodge. That way I'm sure it's OFF. But still if I don't drive it for a few weeks I have to remember to disconnect the battery. I doubt you hurt your battery enough to worry about.

My bet is it won't hurt it at all just doing it once. You've got me confused over the preference of an Interstate battery over Walmart. Johnson Controls makes the batteries for Interstate and Walmart and some versions are exactly the same.

I called the tech department awhile back at Johnson Controls to get more detailed specs on Walmart batteries. At the Johnson factory they test their batteries by running them stone dead, repeatedly.

Unless the trip to town was a real short one, I would be concerned about the battery and/or the charging system. The alternator in most fairly new rigs will put out a LOT of amps, and those big amp numbers should charge a low battery that is otherwise in good shape up within a short time.

If the trip to town involved more than half an hour driving time, I would wonder why the battery did not charge almost fully, and why it was necessary to hook up the charger at all. Most of the time when I use my 10 amp charger, it will start out at 10 amps, but fairly quickly the charge tapers down to much less. Unless the battery was way down or bad when I hooked up the charger!

It has seemed to me that whenever I screw up and let a battery get clear dead that the life of that battery is severely reduced. I don"t know if they short out or what, but they don"t last very long. On the other hand, I have had good luck with batteries in vehicles I use all the time. In the older car I usually drive, it still has the original equipment battery, which is over 8 years old. But that car is used at least several times a week.

I guess if it was my rig, I would watch how it starts in the near future. It may be just fine, but my experience with questionable batteries is that they usually give out on me at the most unhandy moment. It might pay to check the output on your alternator system too.

And the idea of adding a battery minder and keeping that plugged in all the time isn"t a bad idea for a vehicle that is not used often. Still I don"t think a battery minder would handle the problem of leaving the key on for long periods. Good luck!

Northern tool sells a great little charger / maintainer / desulfator that is safe for flooded cell / AGM / and gel cell batteries, plus it has a desulfate feature that removes sulfation from an "OOPS" like you just had.
Their on sale right now for about 1/2 normal price, so is a heck of a deal.

I have 4 of this model, good units that will save a sulfated battery.
BatteryMINDer

I don't think it's good for a battery, however I did it too many times before I discovered the buzzer that reminds me I left the key in went bad. Now I remove key. The only true way to determine damage will be time and do a battery conductivity test on it.

At 10 amps, which I don't consider to be a trickle charger, will take a while.

Just doing it ONCE may not help it but it probably don't hurt it all that much. Sitting long periods completely discharged is not advised and continual deep discharging and recharging uses up what are called "Life Cycles". Other things that harm a battery are Stratification and Sulfation of the plates. A good quality so called Smart Charger with 4 cycles, Bulk, Absorption, Float and Equalize can promote good battery life. A company like Walmart might purchase batteries from different vendors over the years, hard to say who made the one you bought.

John T

Most likely didn't hurt the battery. My concern would be with the alternator. Check the charging system before you venture out. It could have overheated the alternator or taken out a fuse link.

I have Walmart batteries in all my vehicles including my garden tractor and Kohler generator.
The battery in my tractor was replaced after 10 years of use. I gave it to my nephew and installed it since he doesn't make much money. I told him he needs to drive the truck several times each week. Hal

Grandads rule. If it's so dead in won't make the starter click put a charger on it till it does. Don't jump start as if the battery is too dead it's the same as disconnecting the battery with the engine running. As you all know that lets the smoke out of the alternator.

On a newer battery shouldn't be a problem. On an older battery it's probaly going to ruin it.
My experience anyway.

We used to sell Neilsen's rebuilt alternators at the John Deere shop. In their brochure they had a large printed notice that their alternators were NOT battery chargers. In other words, if you have dead batteries, don't depend on the alternator to recharge it for you. That burns up more alternators than any other single item. Let's say you have a normal sized 12 volt battery in your vehicle. It will be right near 70 ampere rated capacity. So, if dead it would theoreticly take 7 hours of a full 10 amp charge to bring it to full charge, or 1 amp for 70 hours or one hour at 70 amps. Now we all know that when pushing 70 amps into a battery the voltage will rise above the regulated voltage of a vehicle and thus the charge rate will be way less than 70 amps. So, it would take a good long trip to fully recharge that battery. Sure it will crank over and sound good. Same as a half full coffee pot will fully fill your cup . That does not mean it is full charge. Put it on a fast charge for a while if you want but finish it off with slow charge until voltage is at 14.5 neighborhood with a very small amount of current flowing into battery. If you can open the cells, they should all be bubbling just ever so slightly. If not, it is not fully charged. I buy very few batteries.

If the battery was totally discharged and cold enough that it froze, it could be damaged. Freezing usually pushes out the ends a little bit and breaks the plates inside, or pushes them together forming a short. Check if the ends of the battery are straight or bulged out.

Let us know how it turns out.

Just one deep discharge and in particular a run to dead flat will deteriate any lead acid battery. An automotive starting battery in particular. Will you see the difference in performance over the next 4-1/2 years instead of the next 5 years? Probably not.
This why is such a problem with Bubba sizing batteries for a solar system. Bubba figures a 100% solar charge each day and installs 100amp hour of batteries and drains a 95AH load of them each day. Needless to say Bubba will be disappointed .