Just replaced battery - ODBEleven reporting onyl 12V with car running

[DV52]

What I'm seeing, however, is that with the car running ODBEleven is only reporting 12V. Even with the dying battery last night, after a jump start, it was reading 14.4V

Concerning? or needs a drive for the ECU to work itself out

thanks

@minke: Hi.

It's normal behavior and lots of folk tend to do it - but my suggestion is that unless you are reading a good quality multi-meter DON'T BELIEVE voltage readings!!

Don't get me wrong - I'm not suggesting that OBD11 is an inferior diagnostic device - it isn't!! In fact OBD11 has become my preferred device since I deliberately stopped participating on the Ross-Tech forum because I could not support Uwe Ross'e ultra right-wing stance on US gun culture (the Ross-Tech web-site banner now includes crossed-rifles against a USA flag - see below)!!

I'm not sure if you are aware of an electrical construct called "VD" (Voltage Drop - not the sexual disease). Particularly on a car - voltage can vary dramatically depending on where on the many meters of wiring the measurement is taken. \

For OBD11, the voltage measurement is made via a pin on the OBD socket that the dongle plugs into. Electrically, this is a far distance from the battery itself - so VD becomes a binding factor and it's the reason for OBD11's "low" voltage reading!

If you are annoyed by the low reading - you can "calibrate" the OBD11 voltage measurement. But this adjustment can ONLY be done with the OBD11 Android version software (it's NOT possible with the iOS version software).

If you want to make this adjustment - do this:

1. Measure the battery rail voltage with a good quality multi-meter
2. Fire-up OBD11 Android software and connect to the car's CAN network
3. On the Home screen - click-on the 4 x parallel lines on the upper left-side of the screen
4. Select Settings
5. Scroll-down to Device
6. Select Voltage Calibrate
7. Enter the voltage reading in Step 1 and press OK

Don



PS:to explain my position - I have no problem with Uwe Ross's personal stance on US gun culture - he is a American citizen and he is entitled to his 2nd amendment rights as are ALL US citizens!

However, I do reject entirely Ross-Tech forum's censorship of counter views when discussing possible solutions to the unbelievable acceptance of the massacre of innocent American school children (which appears now to be the norm)!

The Ross-Tech forum is a public forum and having alternative views about gun control does NOT constitute an offense subject to the moderator's censorship!!

"Patriots" scare the bejesus out of me!!

[minke]

If your battery was fully charged when you fitted it then 12.5V might be just the BMS doing it's thing (leaving some room for charging on the over-run). If it moves to 13.3V after a short while driving than I wouldn't worry about it, that's what my R does after I have given the battery a charge to top it up. I hardly ever see 14.4V. These cars rarely fully charge the battery, which is why batteries no longer last as long as they used to in older cars.

Hi,

Yes. That's what I'm seeing. It seems to oscilate betwee 12.5V and 13.3V. I've an Audi that shows 14.4V so was using that as a reference point (plus years of what my observations have been with all of my previous cars)

Now that I think about it, maybe the Audi is showing 14.4V as the battery is old and not holding charge as well and therefore the BMS is throwing more electrons at it to keep it charged? The battery in the Audi is 8 years old

[minke]

Hey mate - please don't take offence - hillbilly is well known around this forum for being cranky and rude to people. I'm not sure why the mods tolerate it, but it is what it is.

Hah. Didn't take offence... or a gate

With regard to your new battery - where did you buy it from? Did the retailer offer to code it for you? Many battery specialists will do the coding for free with a battery purchase.

Supercheap Auto has a sale on. Century AGM $350. They also take the old battery for free. Actually the person to whom I spoke with indicated that Supercheap often offer cashback for returned batteries. Something to note.

Couldn't get another AGM for less than $500

I know with my OBD11 when monitoring "live data" the voltage is not constant - it will go up and down in a range between 12ish and 14 point something.

Although coding the new battery details into the vehicle is the correct process, there are many people out there who don't follow correct process.

Yea. That's what I'm seeing. I'll see the shape of an electrical volt in the voltage readout when the volts are down at 12.3V which to me indicates that the car is charging the battery. Then when it is is up around 13V there's no symbol which would suggest it is managing the volts being supplied to the battery.

My A4, which has a tired battery I suspect given that it is eight years old, always reads 14.4V-14.5V and that elecgrial volt symbol permenantly showing. I guess trying to eke out the last of its life.

Many thanks