Determining if car battery has much life left

[paulri]

I have put my cars on a 33-36 month preemptive replacement schedule (I find they conk out at that time). I have a new to me Highlander that has been parked in a garage (my cars are outside 24/7), and so far, has had 4-5 years on batteries (car has been in the same area as I live in). The three year anniversary of its replacement is Oct 2019. The cheapo in me wants to try to squeeze as many more months out of the battery as I can get. The impatient part of me that hates it when I have to call a tow truck, wants to replace it now.

I called my local WM TLE and I was told that I can bring the car in, and that it would take about an hour or so, but they can test the battery to see how much life is left in it. Is this a reliable test? Is there in fact a reliable test for how much charge is left in the car battery (I'm talking about the 12v, not the hybrid traction).

 

[mk378]

Hybrids probably don't make a lot of demand on the 12 volt battery. As long as there is charge in the traction battery that is what starts the engine.

The standard test for car batteries is the load tester. It draws 200 or 300 amps from the battery to simulate a conventional car starting, and watches how low the voltage goes. The test itself takes less than a minute. Most of the 1 hour at Walmart will be waiting.

 

[JMJNet]

You can DIY, just get a battery load tester from HF for under $20.
It is an analog type, you can do the test every month to see a trend if it is trending to go bad.

Instead of waiting for 1 hour everytime at Wally.

 

[Hall]

I think the test they do is a "load" test, which tells you how strong it is, i.e. for starting the car. It can't predict the remaining life of a battery though.

 

[Donald]

A conductive test will tell you how much CCA is currently in the battery and the label says how much when new. Its pretty reliable. They probably have a Midtronics tester. Hopefully it takes into account battery temp.

You can buy lower end versions of these testers for $40 to $60.

A temp compensated load test using 1/2 CCA for 15 seconds and check voltage at the 15 second mark is better but few places use this as the battery has to be fully charged.

 

[spavel6]

Might be worth investing in a jump-n-carry (https://www.amazon.com/Clore-Automotive-Jump-N-Carry-JNC660-Starter/dp/B000JFJLP6) and not replace batteries earlier than they need to be. I've found that good batteries last 6+ years without an issue. It seems that 36 months and throw-away is a bit wasteful and uneconomical..

My unit can jump start a completely dead VW diesel, so I'm sure a Toyota would be no problem. Then when/if the battery dies, you can jump it and replace it without calling a tow truck. Plus added protection in case you leave the lights on overnight

 

[Gebo]

Get your own load tester. Great $40 or so investment.

 

[paulri]

Given that my batteries for years have died just before or just after 36 months, this isn't a number I just picked randomly. I'd rather drive to a store and get a new battery on my time, than have to call a tow truck, and hope my family doesn't need our other car that day when I want to go somewhere.

Originally Posted by spavel6
Might be worth investing in a jump-n-carry (https://www.amazon.com/Clore-Automotive-Jump-N-Carry-JNC660-Starter/dp/B000JFJLP6) and not replace batteries earlier than they need to be. I've found that good batteries last 6+ years without an issue. It seems that 36 months and throw-away is a bit wasteful and uneconomical..

My unit can jump start a completely dead VW diesel, so I'm sure a Toyota would be no problem. Then when/if the battery dies, you can jump it and replace it without calling a tow truck. Plus added protection in case you leave the lights on overnight

 

[eljefino]

Where does the Highlander keep its 12v battery? If not underhood, there might be less heat-related stress.

The Prius community has jump started a dead 12v system with a Dewalt drill battery and other lightweight aids.

 

[paulri]

It is under the hood. I think what helped keep it from the heat cycles was that it was stored in a garage that stayed reasonably cool (for a garage in the desert). But now that I own it and store it outside, the battery should suffer more heat/cold cycles.

Originally Posted by eljefino
Where does the Highlander keep its 12v battery? If not underhood, there might be less heat-related stress.

The Prius community has jump started a dead 12v system with a Dewalt drill battery and other lightweight aids.

 

[edwardh1]

who drives this car, and in what conditions - Darkness, cold lonely roads, bad crime areas ?

I like3 year changeouts

 

[paulri]

desert region. exurb area, not lonely roads, no bad crime areas that I drive through. Plus I do have a cell that I keep charged 99% of the time.


Originally Posted by edwardh1
who drives this car, and in what conditions - Darkness, cold lonely roads, bad crime areas ?

I like3 year changeouts

 

[zvm77us]

autozone will test it free
https://www.autozone.com/landing/page.jsp?name=in-our-stores

 

[paulri]

For those recommending that I get a load tester--here is one @ HF for $20. $20 sounds like it could easily pay its way for me with a few months extra use of a battery, as well as still let me know that the battery has enough power for me to drive to WM to get my next one. The ratings are pretty high, 4.5/5 stars from over 500 reviewers.

I take it that this isn't so cheap that it would fall apart, or give me inaccurate readings?

 

[maxdustington]

Originally Posted by spavel6
Might be worth investing in a jump-n-carry (https://www.amazon.com/Clore-Automotive-Jump-N-Carry-JNC660-Starter/dp/B000JFJLP6) and not replace batteries earlier than they need to be. I've found that good batteries last 6+ years without an issue. It seems that 36 months and throw-away is a bit wasteful and uneconomical..

My unit can jump start a completely dead VW diesel, so I'm sure a Toyota would be no problem. Then when/if the battery dies, you can jump it and replace it without calling a tow truck. Plus added protection in case you leave the lights on overnight

If OP does not need to jump cars all the time a lithium jump pack will be sufficient and much cheaper than a JNC. I just bought one for $90 CAD and it went on sale for 33% off on prime day.

 

[Wolf359]

Originally Posted by paulri
For those recommending that I get a load tester--here is one @ HF for $20. $20 sounds like it could easily pay its way for me with a few months extra use of a battery, as well as still let me know that the battery has enough power for me to drive to WM to get my next one. The ratings are pretty high, 4.5/5 stars from over 500 reviewers.

I take it that this isn't so cheap that it would fall apart, or give me inaccurate readings?


The load tester is to answer your question as to how much life is left in the battery. If you get a battery charger and keep it fully charged, the battery will also last longer. You could probably put it on the charger now and you'll probably see that it's not fully charged. I don't like putting it on a trickle charger, lots of stories of people frying the battery due to a bad trickle charger.

 

[benjy]

for those not driving or a lot of short trips a C-Tek charger used monthly will extend any batteries life. of course winters + very hot climates kill batteries as even sealed batteries dry up in places like arizona. any battery that sets with a low charge sulfates + that shortens the life as sulfated plates will not charge. very important to buy a fresh battery when needed + fully charge if possible before use.

 

[rubberchicken]

I usually get 6-7 years out of a battery, and I have a Optima Red Top in my Suburban that was manufactured in 2004, still going strong. Why only 3 years ?

 

[wrcsixeight]

Every time you start your engine, can be considered a load test, if you know how low the voltage falls during starting.

When new my 930CCA group 27 agm battery would stay above 12.2v under the ~180 amp load starting the overnight cold v8 engine.

Now 6 years and some 1100 deep cycles later, it drops to the 10.5 volt range when starting the overnight cold engine.

When it drops to less than 8.5 volts when fully charged and starting overnight cold, then I will consider battery shopping.

Expect voltage to fall lower when the battery is cold and less than fully charged.

How fast the digital voltmeter responds when starting the engine is important too. Some might sample voltage 2x a second, some might sample it 10 times a second. sample rate is not always advertised.

An analog voltmeter might be better for this as one can see the needle swing to the left a certain amount easier than seeing a digital number.

A battery that is just barely able to start an engine is severly degraded, but one just above severely degraded will not have any issues whatsoever, unless it is quite cold. One might even think a battery just above severely degraded is 'still going strong'. The ability to start an engine is not an indicator of strength, not without knowing how much voltage it can retain when supporting the 150 to 200 amp load of the starter.

I can start my overnight cold, 5.2 liter v8 engine on a 11 pound 18 amp hour agm battery that has at most, 170 CCA, voltage falls to 7.8 volts doing so.
When my 930CCA battery degrades to 180 CCA, it will still be able to start my engine unless it is quite cold outside, but I live in coastal California so that is not an issue.

If one regularly achieves true full charges of their battery, they can get exceptional lifespans from them, even in hot climates.
If one expects the alternator and its voltage regulator together are some physics defying instant battery charger, they might only get 2 to 3 years

 

[supton]

Originally Posted by edwardh1
who drives this car, and in what conditions - Darkness, cold lonely roads, bad crime areas ?

Ditto. On my wife's car I thought the battery was turning slow in winter after 5 years, so I swapped it out. My cars, I wait until a cell drops out and swap it out in a Walmart parking lot. Usually by the second jump I've confirmed that the battery has lost a cell. Seems like 5-7 years in my limited experience, although my truck's battery appears original at 10.

But I live in the north. Our "brutal" heat season is pretty sure. And our truly cold season is pretty sure (you know, when temps are below 0F for any length of time).