How to discharge a removed car battery

Well the flat earth would have four corners, right?

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This is true.

That was my thought. My lawn mower battery (cycle battery) has square posts, but no car I’ve ever had that didn’t have the side posts.

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if OP’s battery has side posts too, they could change the cables and connectors to use the side posts instead of the top posts.

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I don’t want to continue this discussion since he/she/it just needs a new battery, but when I had side posts, I had screw in adapters to create round posts to hook a charger to. Yeah that would work except been a long time since I’ve seen a battery with both.

We needed a new battery for the wife’s car last year the original battery that came with it had both as did the new one we got 1992 Buick.

if the battery won’t work for your application because of the mangled negative post, then you got the proper repair by replacing the battery.
(although, I agree with the others that this is likely fixable, and your original battery was fine.)

Your best plan of action is to ask whomever installed the battery you are trying to get warrantied to help you with the cost of the new one. Oh, and just so you know- Walmart is not likely to issue a refund on the new (now used) battery if you decide to try to return it and go back to using the old battery.
12.6v charge on an out of the vehicle battery is completely normal, and not what actually gets tested when testing a battery.

#LookingToScamTheSystem

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You’ve gotten some good advice here. If you have the money, I’d suggest having a new battery installed by a competent tech - have them show you how to properly protect terminals (coat with grease) and when and how to inspect and clean them. Also how to remove acid from the top of a battery when that is needed. Consider it a good education.

If you want to save money and your existing post isn’t too bad, wire brush it clean and try lead “battery post shims”, available on line. If too mangled for shims, and you have the skills, try filing an as large as possible flat surface on either the top or side of the post, drill and tap for a machine screw of diameter ~ 1/4-1/3 the span of the flat area, and bridge between the terminal and connector with a strip of soft copper - use the purest and softest copper you can find, OFHC copper is best. (Flattening heavy gauge copper wire with a hammer is one way to get high conductivity copper.) At the clamp end you can secure the strip to the clamp’s tightening bolt. Try to use a hard copper, brass, or stainless steel screw, but common steel will work. Coat all with grease. If repairing the “hot” terminal (positive on modern cars, but not all old ones) ensure the end result is robustly insulated.

When working on a battery, disconnect the negative terminal and wear eye protection with all- around coverage. If your battery has vents, cover them with a damp rag to prevent flame propagation (sparks, hydrogen) to the inside, which can cause a battery explosion.

Ken , this person has a new battery but has never said who installed it. They want the purchase price refunded when they return the old battery which was declared good . As for the mangled post it has not been told who did that or why this mechanic could not figure how to secure it .

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Years ago, I used a baking soda and water solution to clean battery terminals, but I really prefer this stuff nowadays:

image

Coupled with an old toothbrush, it does an excellent job of removing the corrosion. Afterwards, re-coat the terminals with Dielectric grease.

Sorry for the misunderstanding - I didn’t want to repeat what others have told him, just to address his choices given that his problem probably won’t be covered by the warranty.

I’ve taken batteries off of scrap cars for years (that obviously weren’t cared for the best with dielectric grease, etc) and I do not ever recall seeing one mangled from corrosion. I have never seen corrosion eat into the lead. Maybe that’s a thing that happens, though.

Maybe it only does that to square battery posts. :wink:

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I thought the terminal was mangled to the point that it was square like. All I’m saying is that the battery terminal doesn’t need to make contact all the way around. Some cut up sheet metal or copper can be put in there one one side to make the clamp tighten down and it will work fine. Even some cut up copper wire that is stripped of insulation can be shoved in to one side to fill the gap and allow the clamp to tighten. Even non conductive things like plastic or wood would work if it’s done only to one side.

Nobody refuted the bogus advice from the mechanic that the battery terminal must make contact all the way around or it won’t work well. Have you ever used jumper cables???

A mangled battery post is not going to be square as you did say . As for you having a thought , that could be another whole thread.

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THANKS to all who provided useful advice or outside-the-box ideas! Different day, different employee, different result. I brought my old battery back to Walmart again to see if 2/3 employees would honor the warranty, or if 2/3 would not honor the warranty. It turns out 2/3 employees would honor the warranty. Mission accomplished.

For all those asking, I don’t know who installed the battery, but it wasn’t me or the quality mechanic who fixed the old (now exchanged) battery to ok albeit something like 90% working-power condition (due to lack of cylindrical shape of battery terminal). And to anyone who doesn’t know, it reflects poorly on you when you blindly judge/insult people who have zero capability to defend themselves. The mechanic who fixed my car came as highly recommended from a local electrician, and he let me watch over his shoulder and taught me everything I could possibly need to know about the future of my car’s battery situation. Sometimes it’s hard for me to trust mechanics. This one is the best I’ve had in my life. :slight_smile:

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I failed to answer why I didn’t let them check it while I was there. The option was not provided to me. I was not told a test would be necessary to return the old battery, when I I asked if I would be able to return it, so I had no reason to request that they test it. I was perfectly happy with the yes answer, that I could return the old battery because the clamp would not seat perfectly to the battery terminal.

Being perfectly happy with that answer, I’m not the kind of person who would then say, “I want you to check the battery voltage before I exchange it. Can you do that for me?” The thought wouldn’t occur to me… ¯_(ツ)_/¯

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OK. Not to prolong it but if you are saying the battery post was defective from the start and not round, then I agree they should have taken the battery back. The mechanic tried but couldn’t make it work. But it should have been not accepted right off the bat is all. It was not clear to me who mangled it and the fact that it was defective from the start.

Now if that is not true and the battery was fine and got mangled in the process of installing it, I disagree.

Are you referring to me saying that the mechanic’s advice that the battery cannot properly function due to the mangled battery terminal is bogus advice? If so, you’re saying I’m not allowed to disagree with his advice since he is not here to defend himself?

I would not purchase a battery from them, If the battery terminal are bad replace them try interstate batteries they do good work.