Is there any value in having a handheld battery tester vs a multimeter? I mainly want to keep an eye on the truck battery health since the heat tends to shorten the lifespan. Normally I just meter it but not sure if that's sufficient to avoid being surprised when it fails to crank.

Neither one is of any real value for testing car batteries.  You need a real load on the battery.


In my experience, batteries are fine up until the last few starts before they are not.  If it sounds like it cranks slower than usual, throw your jumper cables in the truck.

If you want piece of mind, forget about a tester and buy a jump pack.

They're very different tools. If you're trying to measure a battery's health, you really want a battery
tester.

Performance under load shows far more about your battery's condition than a simple surface voltage
measurement, which is what a multimeter gives.

As batteries age and die, their internal resistance goes up, which results in lower amp output under
load and larger voltage drops under load. Both of those will show up with a battery tester and won't
with a multimeter.

Midtronics has you covered.

$500

I agree, I've got both in the truck now. Cranking is fine but the age is approaching the typical replacement timeline. I was hoping to preempt a forced emergency replacement and do it on my own schedule.

Understood. No real value in the multimeter for what I'm looking to achieve.

Thanks but I can't justify spending pro money on this. Anything similar for amatuer, poor money?

NOCO

Then I would just replace it.  It isn't worth spending hundreds of dollars on a tester to get the last few months out of a battery.  Especially since the tester can't actually predict when it will fail, anyway.

I'm not sure how worthwhile it would be, but there is something you could do with your DMM that may let you see if the health of the battery starts to fail.  Leave your lights on for maybe 10 minutes, then check the voltage, (with lights still on).  Once you have a baseline, you can repeat the test periodically, and see if there is a change.  The temperature of the battery will make a difference, so it would need to be somewhat consistent.

The heat and dry will kill a battery, be sure to keep the electrolyte at the correct level.
They sell fillers that automatically fill to the proper level.

Battery filler

Thanks, that makes sense. I'll save the money and not worry about trying to predict its demise.

A battery tester will give you internal resistance and other data points that are 99.9% useless to most people.

In my house there is only ONE  tool  that can truly test a car battery.  You can find them used,  marketpharce,  C/L, etc.  Generically,   a  battery  or  battery /starter  load tester,   "carbon pile."  

There are smaller  (but probably not cheaper)  solid state testers that are supposed to pulse load the battery and are much smaller, but I do not trust them.

People have posted that various  car parts and other stores  will test a battery for you,  free,  aka  places like  Oh'?Reallys   Auto Parts.  

Basically a carbon pile is a huge giant adjustable resistor in a box,  in series with a large shunt, hooked to a meter to measure amperage.   Some have a switchable meter,  some have two meters,  volts and amps.   You  do one of two things---you adjust the load to match the batteries  rated  load and see if the voltage is acceptable,  or you load the thing  until the voltmeter pulls down to about 10.5,  count  to whatever the  tester says  (mine is 10 seconds) and then  re-adjust the  load  to pull the batter to 10.5V  and read the amperage.  If it is below  a  guess as to what is acceptable,  the battery is gone,  or undercharged.   Around here,  anything 100A or better at  a 10.5V  load  will crank everything except the diesel, which has two  HEAVY  group 27s

AND THAT BRINGS  another point to buying batteries.  When buying  lead/ acid batteries,   one of the best ways to know you got a good heavy duty battery, is to avoid  the hype and JUST HEFT IT.   The heavier battery wins   always.

Thank you all for the education. You've persuaded me to save my money. I appreciate it.

Harbor Freight

https://www.harborfreight.com/100-amp-612v-battery-load-tester-61747.html?utm_source=google&utm_medium=cpc&utm_campaign=12144811130&campaignid=12144811130&utm_content=117789275758&adsetid=117789275758&product=61747&store=606&gad_source=1&gbraid=0AAAAADAHb4f5B3X-rq_O3Q5MIG8MIBOlh&gclid=EAIaIQobChMI-fT6zJOvhwMVRACzAB3EGQhYEAQYByABEgKmsvD_BwE

I have the older model of this unit, and it's been GTG. It is a load based tester that dumps a very
large load on the battery very briefly (milliseconds) and gives a CCA and voltage readout.

Part of my periodic maintenance is recording the CCA once a quarter in the morning after the
car was driven the day before. Wear becomes pretty noticeable and pre-failures as well.

I replace any battery when it can't hit 80% of rated CCA -- that's pretty early for most people
but I live where a dead battery is a pain in the ass to take care of.

You could buy a load tester from Harbor freight.  Multimeters won’t apply the load required to crank the car over so you could have enough volts but not enough amps.

The best solution would probably be to spend your money on a NOCO jump pack. When the battery does fail, you can pull out the jump pack to fix the immediate problem and then go buy a replacement battery.

This right here!!! I keep a GB70 in every vehicle, and have one in my tool box at work. For the average person this is the best solution. I also have a midtronics tester at home as well as a Bosh BAT135 tester at work, and I can tell you that if you use a tester you will be replacing a lot of batteries, because most of them will test bad on the tester even though there is tons of life left in them. The battery in my old beater Impala has been testing bad for 2 years now. I'm guessing it wont make it through this coming winter but I am prepared with a jump pack.

I already have a jump pack so that provides some peace of mind. I was hoping to avoid the potential forced replacement situation happening when I'm somewhere in the middle of the backcountry, but that's a lower chance.

I've wondered about the testers showing a bad battery when there's life remaining. I don't recall ever taking one in for testing and being told it's ok.

My policy has been that if I’m having doubts about my battery then I’ll just suck it up and replace it. Not worth it to me to try and scrape out an extra month or two out of a dying battery.  This goes triple if I’m getting ready to go on a long trip or nasty weather is forecast.

I have one of the digital load testers but have a hard time coming up with the CCA for the battery for various small batteries that I want to test.  How do you guys determine the CCA of a small battery, say a 1270, so that you can properly test it?

Yep. Same goes for tires.

When the battery is brand new I put it on the charger for a day, let it sit for a day, and then test it and write down the
the measured CCA with a sharpie. That establishes the baseline and then I go from there.

I've got one of these from HF, have used it to "test" a couple of batteries I had concerns about.  It suggested I replace 1 of them...

https://www.harborfreight.com/12v-digital-battery-and-system-tester-58759.html

Try testing it before it’s causing a problem. Typically people don’t actively test things they THINK are good. It’s when things DON’T work they get tested. This would explain having a battery tested and being told it’s bad.  Try testing the one in your wife’s car or one you just picked up.

I bought a lower cost version of that.  It displays CCA and impedance.  When I suspect a battery is slow cranking, I test it and usually find CCA is 1/2 of rating or less.  I also tested a brand new battery and CCA was actually higher than the nameplate rating.  

I have used it many times, as I had 9 vehicles at one point.  It is an extremely useful tool.  You can't get there with a standard multimeter.

CCA can't be measured with a handheld tester.  It's only roughly estimated from the internal resistance.   You actually can measure internal resistance with a DMM if you can measure current.

Try teaching internet dudes how to measure current.    This is usually how it goes:



Also, it isn't an estimate, it is a calculation. Impedance, resistance, and load testing (fucking current and shit)  Don't poke the bear, I actually do this shit for a living.  I have a pallet of impedance matched (same lot) batteries in my office right now.  I also have a real load tester, the one below isn't it.


Two things are helpful here. Heavy duty jumper cables in every vehicle, and an AAA+ membership.  Also, not being a cheap-ass and running old car batteries and dirty terminals.

That's what the jump pack is for, no?  You're going to have to replace the battery at some point.  The jump pack ensures you can get back to civilization and do so.

Or take it to autozone and have them test it before you go.

Not poking any bears.  Just making conversation.  

Even a HF battery load tester is better than a Voltmeter.  Gives you some indication.  Some auto stores have digital testers that test alternators as well.

Did anyone get the cheap battery tester in the Amazon deals thread a couple days ago?  I have one on order but don't expect much for $3 (assuming it comes).

https://www.amazon.com/gp/product/B07TQS9RXW