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Can charging battery prolong its life

A mechanic did a free battery test on my car battery and said it’s low on charge so I should get it replaced while saying the battery is probably not gonna die overnight, but should be replaced before winter. My battery was drained a lot about 4 months ago so it was struggling to start. This was because I had not driven the car for 2 months, but I charged it, and it’s been cranking very well. Battery is 4 years and 8 months old. At this point, can I charge it again, and increase its lifespan or is it best to just get it replaced at Walmart auto center for about $85 including labor? Car has other issues so I want to minimize investing in it.

the mechanic gave you sound advice on a 4 1/2+ year old battery that has had a hard recent life.

If you want to keep using the car and have it reliably start on you- replace the battery. If reliability isn’t an issue then run it til it dies- which could be while sitting in traffic, or could kill the alternator in the process causing more issues and untimely breakdowns.


The battery should be charged to full charge by driving the car. The only time that is not true is:

  1. The battery is defective. In that case, use of an external charger will do no good. Replace the battery and check the alternator.
  2. You only drive for very short trips. It takes some time for the battery to charge. In this case, an external charger may help.
  3. The alternator is defective and puts out a low current. In this case, an external charger may help short term, but the alternator needs to be repaired or replaced.
  4. The battery connections or cables are corroded or loose. In this case you need to clean or replace them.

You can have combinations of the above also, such as an old battery and too many short trips.

Remember, each time a battery is completely discharged, it suffers some internal damage. Do this many times and the battery is toast.

Note: these are my opinions, others may disagree…


The mechanic used a conductance battery tester and measured the Cold Cranking Amps which is good indication of the condition of the battery.

That’s why they recommend the battery be replaced before winter.

The battery is charged each time the vehicle is started and driven.

When the battery in my vehicle started having problems starting the engine, I tested it with a conductance tester.

The battery was rated at 730 CCA’s. And the conductance tester measured the CCA’s of the battery at 310. With a bold message on the display, REPLACE BATTERY.

Since I’ve replaced the battery, I haven’t had any starting issues.

And the old battery was about five years old.


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If it strands you some place a typical service call to jump your battery is anywhere from $25 to $75. You can avoid that for $85 , seems like a logical move to me.


The battery is a little old, but as long as it is capable of starting your car, I would not replace it. Running it dead one time is not the end of the world. Only if this happens multiple times will it cause damage.

Very good advice in the above posts. Keeping a battery charged will prevent it’s life from being shortened, you cannot extend it. If you allow it to be discharged, especially near dead, you damage it and shorten it’s life, no way to reverse that. You have 4+ years life out of this battery, be happy with that and get the new one from Walmart. Advance, Costco etc also have batteries. Shop around for the best price/warranty and put this problem behind you.

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You must live in warm climate. Here in the North East batteries easily last 7-10 years. In fact I’ve never had a better NOT last at least 7 years. I’ve had car batteries last over 12 years.

I think your experiences are exceptions rather than the rule. Car batteries last an average of between 4-6 years, but actual life, obviously, depends on a number of things. Climate is one of them. In cooler climates they are expected to last a little longer, but 12 years is an exception.

I did suggest to the OP NOT to replace the battery at this point.

No they are not. Heat is what kills batteries. Colder climate drastically increase the longevity of a car battery.

I’ve owned cars/trucks for over 40 years…usually keep them over 10 years and hundreds of thousands of miles. Never had to replace one under 7 years old. I don’t know anyone who also keeps their vehicles a long time to replace a car battery that’s under 7 years old.

Florida or Texas - that’s a completely different story.

Mike, you are correct. But I get ansy when the battery is older than 5 years and replace it.

You won’t go wrong to just replace the battery now, but since it is summer (presumably where you live) you may be able to get by, just be sure to keep the battery fully charged. As long as it cranks reliably, you are good to go. Keeping the battery fully charged means if you don’t drive the car quite a few miles every day you may need to charge it with a battery charger from time to time. Try to do that using the low current (usually 2 amp) charging mode, as that is easier on the battery. It can take up to 24 hours to properly charge a battery on the 2 amp mode if it is fully discharged, but usually 6-8 hours does the job for a partially discharged battery.

Short answer recharging your battery will not increase it’s life.

Important Update - So I did get a new battery put on today. Came home, and did voltage test using my multimeter, and was surprised to find that both old and new battery reads at about 12V with engine off. I guess I should perhaps have done this before buying the new battery. For my education, if the old battery 4.5 years old is reading 12V with engine off, doesn’t that mean that it’s holding the charge and has more life left? The mechanic who advised me to change the battery didn’t use a multimeter. He used one of those tester that has lights for failed, low, and good. Any further thoughts?

I want to add the battery was completely drained due to bad alternator back in about August 2016 and highly drained once in January because I didn’t drive the car for few months. Both times, I recharged, and it seemed to have fixed at the times.

Volts are not indicative of amps, the power needed to start your car. A small battery can read 12 volts, but it does not mean it will start your car. A battery test of amps is more important than volts. My daughters battery for example when near death showed 12 volts, but only 65 amps of cranking power, where the new battery had 850 amps.


Concur w/Barky’s comment above, the 12 volt output OP measured doesn’t reflect the battery’s ability to deliver power to the starter motor. That’s why the mechanic used the type of tester with the lights. Those don’t measure only the voltage. They measure the battery’s ability to deliver electrical power, which is the product of voltage X amps. We commoners here refer to that as a “load test”.

12.0 volts exactly or what? A reading of 12.0 to 12.3 after recharging is a tired battery on its last legs. If the new battery is freshly charged from driving around (that’s how batteries usually get recharged, not you physically doing it) and the voltage reads 12.6 or above, Yay! That’s what a new battery should show.

A further question is; Why do you still have the old battery? Be sure and return it for the core charge so it gets properly recycled. Do NOT toss it in the trash!


A battery that reads 12.0 volts is a dead battery.

I don’t know of a single shop that uses a battery load tester anymore.

It’s old, unreliable technology.

Every shop I know uses a battery conductance tester to test battery’s.

A load test and a conductance test are two totally different things.


Ok, I went to one of those well known part store, and had them do a test on my new battery. Their reading was Good battery, voltage is 12.6 volt, measured 578 A (SAE), rated 600 A (SAE), temperature 114 F. The CCA on this battery is 600 so I think 578 is the amperage they measured which appears to be within normal range? (I’m guessing the amperage will be a little lower during summer than in winter.) Do those #s look right in your opinion? Is the amperage suppose to be lower in summer than in winter?

Those look like pretty good battery numbers to me. I concur with the test assessment, your battery is still ok. Summer vs winter? I’d guess the amperage output would be a little less in colder weather, and higher in summer. That’s why we usually see a lot of no-crank problems posted here in the fall and early winter, the battery is on the verge of failing but the summer temperatures are just enough keep it working. Then in the fall when colder temperatures prevail, no crank. I think those battery testers take the temperature into account when they display the results.