mobiledynamics
Well-known member
When trying to see/determine V dips, by what means are you attaching multimeter to the battery posts and seeing the data as you drive ?
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Driving with a MM on battery leads
- Thread starter mobiledynamics
- Start date
wyliesdiesels
Well-known member
Why not buy a voltmeter and mount it in the car somewhere?
American Locomotive
Well-known member
They sell all kinds of multimeter leads. Ones with alligator clips, ring terminals, bare wires, etc...
ripperd
Well-known member
I'd just connect the multimeter to the cigarette lighter outlet pigtail. If not under load, that should always be battery/system voltage I believe.
OP
mobiledynamics
Well-known member
How accurate are the cig plugs. There is a .4 differential when I'm reading the reading off the cluster vs. MM/posts
kbeefy
Well-known member
I would definitely confirm the cig lighter shows battery voltage, personally wouldn't trust it.
I have a fluke 233 with a remote display, but I also just received a PokitMeter, that is supposed to display/graph on your smartphone via bluetooth but I haven't tried it yet.
What kind of voltage dip are you looking for? Most conditions can be replicated without driving anywhere.
I have a fluke 233 with a remote display, but I also just received a PokitMeter, that is supposed to display/graph on your smartphone via bluetooth but I haven't tried it yet.
What kind of voltage dip are you looking for? Most conditions can be replicated without driving anywhere.
OP
mobiledynamics
Well-known member
I did end up determining it was my battery. The charging system was fine. Even with battery removed, charged, rested and brought to AutoZone, they said the battery was fine.
However, in monitoring V with the battery in the vehicle, there were times where I def. saw it dip below 13V. Replaced battery, all is running well. I was able to see live voltage with the Fluke remote display. Was curios how others diag. when you needed to see V in real time driving
However, in monitoring V with the battery in the vehicle, there were times where I def. saw it dip below 13V. Replaced battery, all is running well. I was able to see live voltage with the Fluke remote display. Was curios how others diag. when you needed to see V in real time driving
vavet
Well-known member
Glad you got it figured.
I have a bluetooth OBD2 reader that connects to an app on my iPhone. It's on OBD2 reader on steroids. I also have a handheld OBD2 reader. Either will display battery voltage, but the bluetooth reader with app will let me log it, upload it to dropbox/email it to myself so I can display it in a spreadsheet and compare to RPM, vehicle speed, load, temp, etc. If you know the route you drive with it, you can imagine where you are in real time, how big that hill is and compare to the data.
I have a bluetooth OBD2 reader that connects to an app on my iPhone. It's on OBD2 reader on steroids. I also have a handheld OBD2 reader. Either will display battery voltage, but the bluetooth reader with app will let me log it, upload it to dropbox/email it to myself so I can display it in a spreadsheet and compare to RPM, vehicle speed, load, temp, etc. If you know the route you drive with it, you can imagine where you are in real time, how big that hill is and compare to the data.
Craptain
Well-known member
I also use bluetooth reader to my phone. Love it and use it for all the gauges that are not installed in the car.Glad you got it figured.
I have a bluetooth OBD2 reader that connects to an app on my iPhone. It's on OBD2 reader on steroids. I also have a handheld OBD2 reader. Either will display battery voltage, but the bluetooth reader with app will let me log it, upload it to dropbox/email it to myself so I can display it in a spreadsheet and compare to RPM, vehicle speed, load, temp, etc. If you know the route you drive with it, you can imagine where you are in real time, how big that hill is and compare to the data.
Sent from my SM-G930T using The Garage Journal mobile app
OP
mobiledynamics
Well-known member
I dunno if the OBD with a dedicated tool that graphs it would be accurate or not ? Presuming/assuming, the the cluster data is coming for the OBD. The cluster was .4 lower than readings with a MM right on the post.
Stuart in MN
Well-known member
As for attaching to the battery, I simply made up a set of leads that are long enough to reach inside the car - clip them on, run the leads out through the back of the hood and in through the car window, and take it for a drive. You can buy long leads as well, if you prefer.
kbeefy
Well-known member
I dunno if the OBD with a dedicated tool that graphs it would be accurate or not ? Presuming/assuming, the the cluster data is coming for the OBD. The cluster was .4 lower than readings with a MM right on the post.
Instrument cluster is the Lie-o-meter. Depending upon vehicle it can be drastically inconsistent.
I would also prove out the bluetooth OBDII apps/dongles....
OBDII has 2 direct voltage sources, neither are always reliably charge or battery voltage.
PID's the OBDII system can also be subject to voltage loss and resistance in the system.
For all of the above confirm the voltage your seeing matches a calibrated multimeter reading at the battery posts or alternator charge post, depending upon what you are trying to diagnose or fix. And do a proper charging system test before driving around trying to watch your multimeter.
I've seen 2-3v difference between charge voltage and battery or ground just due to loose or corroded connection on a driving vehicle that passed a preliminary alternator and battery test.
nafterclifen
Well-known member
Glad you got it figured.
I have a bluetooth OBD2 reader that connects to an app on my iPhone. It's on OBD2 reader on steroids. I also have a handheld OBD2 reader. Either will display battery voltage, but the bluetooth reader with app will let me log it, upload it to dropbox/email it to myself so I can display it in a spreadsheet and compare to RPM, vehicle speed, load, temp, etc. If you know the route you drive with it, you can imagine where you are in real time, how big that hill is and compare to the data.
What product and software are you using? I would love to do some data logging.