What would kill batteries in < 20 mo for daily driver in temperate climate?

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Feb 7, 2012
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Portland, OR
Wondering what issues anyone may know of that can make car batteries prematurely fail when it's daily driven and not exposed to climates with excessive heat?

Have a CX-5 using Group Size 35 batteries. Last two batteries I've had to replace at about 19 months. It's daily driven in a temperate (Oregon) climate. No aftermarket accessories like crazy car stereo or anything.
 
Some vehicle brands and models have had problems with the computer not going to sleep properly when the car is shut off, this drains the battery.

Also some use two stage charging to increase mileage, the charging system goes into a lower voltage mode when there's little load and the battery is close to being charged. This leaves the battery perpetually under charged.

Both of these can reduce battery life significantly.
 
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Excessive parasitic draw while the car is sitting, coupled with short drives where there is never adequate time to return the battery to near full.

I have data from my own vehicle in terms of how long it takes the charging system to return that which was used to start the overnight cold engine.

It is about 45 seconds when the voltage regulator is seeking and holding 14.7 volts.

This is determined by amperage. I was holding the battery at 14.7v and noticing how many amps were required to maintain that voltage before starting the engine.

After starting the engine, once amps taper to that same level at 14.7v, the battery is as at the same state of charge as before starting the engine.

It took ~45 seconds at 14.7v on my vehicle for this to occur. This is with a precise 500 amp 50MV deltec shunt measuring amperage into and out of the battery.

So unless one drives for less than ~45 seconds, short trip driving is by itself not the cause of premature battery failure, but short trip driving has no chance of returning a less than fully charged battery to full charge, and with ideal charging voltages, which NEVER occur in 99.99% of vehicles on the road, a lead acid battery cannot get from 80% to 100% charged in less than 3.5 hours.

I know that many will say it takes 5 or more minutes to return that which the starter used to start the engine. I can;t see this happening on a modern fuel injected gas engine, but likely was true with carbs and longer engine cranking times and perhaps multiple starting attempts being required.

Likely it took longer than 5 minutes in such circumstances.

Since fuel injection and quick starting vehicles became the norm, batteries have become lighter and lighter in the same size group, with thinner and more fragile plates more susceptible to shedding material. This makes them more susceptible to degradation when cycled, even if only to 80%, and more susceptible to heat and vibration.

Vehicles today have much higher parasitic draws, which make it harder to get the battery fully charged especially when they sit unused often, and many vehicles are intentionally keeping the battery at lower states of charge in order to squeeze out some executive bonus money when CAFE standards are met.

Marine batteries are more durable than dedicated starting batteries when cycled deeper, but come nowhere close to actual deep cycle batteries in this regard. A group 27 starting battery in 1970 would likely be 15% heavier than a group 27 starting sold today, perhaps even heavier than a marine group 27 which can be as high as 62 Lbs for a marine and as light as 48lbs for starting.
 
Designed Obsolescent
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Either but the Walmart Everstart Max with the 5-year warranty or the Costco Interstate with 42+ month warranty.

Get something for batteries dying incredibly early...
 
What battery manufacturer? If it's Exide, maybe they're just not good enough? A daily driver, especially if you're going at least 5 miles, shouldn't be killing them unless there's really bad battery connections or a charging system problem.
 
My BMW was killing batteries. My BMW specialty shop found the problem. The AC fan was coming on at random times when the ignition was off. The battery could be run down to a no start in as little as a couple of hours. Apparently a common problem with BMWs.
 
Originally Posted by Trav
Check the voltage from the alternator.


This. I had a Saturn auto that would shift into 4th at every stop. Turns out the alternator was putting out 17 to 24v!!
 
The 1/2amp floater I bought at HF for 4.99 works great for maintaining the Rats battery. I was gonna put it on the Fridge's 01/20 Maxx 24f, But a 3hr run to midstate on the 'Pike Tues, should have fixed. But for grins, I should check it
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I would first get the alternator output checked at auto parts store. I the alt out put is good, then check for the amount of current draw after the engine is off. I don't have a value for the parasite draw but, it should be low-Someone will more knowledge will give a value. If the alternator out put is good and the parasitic draw is reasonable then it's the battery either bad or undercharged due to lack of driving. Ed
 
Originally Posted by ondarvr
Some vehicle brands and models have had problems with the computer not going to sleep properly when the car is shut off, this drains the battery.

Also some use two stage charging to increase mileage, the charging system goes into a lower voltage mode when there's little load and the battery is close to being charged. This leaves the battery perpetually under charged.

Both of these can reduce battery life significantly.



This ^^^^^^^^^^

And like Trav said check the alternator..

And check for too big of a parasitic draw.
 
When you buy a new battery, charge it always. No matter what they tell you at the store. All new ones I bought in past needed this.
 
Originally Posted by Imp4
Either but the Walmart Everstart Max with the 5-year warranty or the Costco Interstate with 42+ month warranty.

Costco dropped their 42-month replacement warranty to 36-months a little while back. Even their new AGMs have the same term.

I contemplate this as my 46.5 month old Costco battery has revealed itself as unable to hold a charge during these times of home detention and extended idle times.
 
Originally Posted by Carmudgeon
Originally Posted by Imp4
Either but the Walmart Everstart Max with the 5-year warranty or the Costco Interstate with 42+ month warranty.

Costco dropped their 42-month replacement warranty to 36-months a little while back. Even their new AGMs have the same term.

I contemplate this as my 46.5 month old Costco battery has revealed itself as unable to hold a charge during these times of home detention and extended idle times.



My AGM is a little over 1 year old, and it is not doing too well holding surface charge. Short trips and don't drive it much.
 
Regardless of the reason one fix and always a good idea relatively simple and cheap which is to plug into a smart charger in the garage or driveway at regular intervals.

Most of the good ones come with a quick connect making using it a simple affair for anyone.

As the other guy said - the battery will never fully charge off the alternator regardless and aregular topping up will extend the life considerably (11 years now in my case )

Between 5 and 10 amps is perfect.

UD
 
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Assuming there isn't an electrical short in the car or something staying on, just get a cheap battery tender/smart trickle charger and put it on every 2-3 weeks or so to get the battery up to 100% state of charge.
 
Originally Posted by ondarvr
Some vehicle brands and models have had problems with the computer not going to sleep properly when the car is shut off, this drains the battery.

Also some use two stage charging to increase mileage, the charging system goes into a lower voltage mode when there's little load and the battery is close to being charged. This leaves the battery perpetually under charged.

Both of these can reduce battery life significantly.
+3
Mazdas are notorious for this.
 
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+3
Mazdas are notorious for this.


Didn't know that but not surprised. My 2012 Mazda3 drains the battery if left sitting for 2 weeks. Called the dealer and they said its 'normal' (yeah this was 8 yrs ago). So got a trickle charger for when I have to leave it sit. This is my mall crawler and haven't had any other problems so haven't been on any Mazda forums. BTW - the battery is the factory original so am pushing my luck and will get a new one before next winter.
 
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