Set your DMM to DC volts to the appropriate DCV range (or AUTO), enable the MIN/MAX function, connect your test leads across the battery terminals, and start the engine.. let it run for a few seconds then shut it down. Take note of the MIN value registered .. it must not go below 9.6 volts.
Best option is to have a BATTERY tester though.. You can measure the CCA value and internal resistance in addition to SOC and SOH. AFAIK, our local dealerships use the MIDTRONICS conductance tester.
Well, what if the car doesn't start? Would the min/max values still matter in trying to get a glimpse of the health of the battery?
I completely agree in having a tester that's specifically designed for car batteries. I would invest on one when I see fit. Right now, I'm just being curious.
As for the BM2, is that the most recommended bang-for-the-buck tester nowadays? Or is there anything better? I'm very keen into buying one of those.
Personally, I wouldn't invest in a battery tester since I already have access to a voltmeter that records minimum and maximum values, but that's just me. I'm comfortable enough with batteries that I don't need to rely on someone else to do it for me.
A good voltmeter and a little knowledge is all one should need. If you already have a min/max voltmeter, consider learning more about lead-acid storage batteries.
Battery University
Predictive Test Methods for Starter Batteries
Lots of good information there.
Best wishes.
__________________________________________
View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)
The link provided by Eggman is a good read.
I think you were wondering why despite a full charge indication on your battery and yet it was not able to start the car. This is because the internal battery resistance has increased much. As such, the Cold Cranking Amps of the battery has greatly diminished and so cannot crank the engine. You can try a little experiment.. put a 1-Kohm resistor in series w/ your DMM test lead and take a voltage reading of your battery.. you will still have a good reading but put a 5watt 12-volt bulb w/ that resistor in series and see if it lights up.
I suggest that you take a reading of your new battery now and use it as a baseline reference in the future.
As you crank the engine, the voltage dips to a value lower than the voltage you normally get when the engine is not running. As your battery ages, this value gets lower.
If you get a MIN value lower than 9.6 volts, you can then prepare to buy a new replacement. If you get a reading of say, 6-volt MIN value, you will not be able to start the car.
How to Properly Check the Juice in Your Car Battery
https://www.popularmechanics.com/car...a2074/4221215/
CRANKING VOLTAGE TEST
http://constructionmanuals.tpub.com/...ge-Test-92.htm
For the BM2 .. I don't have to carry my DMM or Battery Tester during my trips. I had previously used a Pivot MegaRaizin copy w/c supposedly has a cranking monitor feature but no .. it was just a voltage monitor plus those electrolytic caps.
Last edited by Mitz; 05-18-2019 at 01:01 AM.
NAPA, AutoZone, Advance Auto, Batteries Plus, & O'Reilly all list group 35 &/or group 26R batteries for the Mirage, and these are very common batteries. My Subaru Forester takes the exact same group 35 battery as my Mirage. Walmart & other discount stores carry these battery groups, too.
The original battery may be slightly different in size, but who cares? As long as it fits in the battery box, it should be good.
Last edited by Mark; 05-18-2019 at 04:38 AM.
Ugh.
I've searched many online auto parts vendors and None of them say the factory Mirage battery is Group 85. They All say a Group 35 battery is the correct replacement. On top of that, I've found varying dimensions for the factory 55D23L battery.
Hitachi 55D23L
GS Yuasa 55D23L
Who said the Mirage factory battery is Group 85?
__________________________________________
View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)