Possible stuffed alternator - under charging?

[pawky]

I'm hoping the brains trust can advise me on this one because I am confused.

First the vehicle details are:
MY2015 disco 4 SE 3 litre high output motor. 95k on the odometer. Traxide kit under bonnet. Brand new starter battery and 4 yr old optima yellow top. Both batteries load tested and are good, although the optima is getting a little old rated at 75% of original health.

The problem
I'm part way through a 4 month WA trip and my alternator appears to be playing up.
For the first couple of weeks of long travel days the alternator would start the day pumping out approx 14.5 v and slowing dropping back through the day to eventually 13.9 v approx by day end. All good.

Now my alternator barely squeaks out more than 13.2 v (often less than 12.8) despite regular driving of multiple hours at highway speeds. I have some example charge logs recorded at the aux battery below.

https://uploads.tapatalk-cdn.com/20180805/865ed46ef5dac2bd3524b61be2c40a8e.jpg
The yellow boxes show the driving period. Low voltages coming from alternator.

https://uploads.tapatalk-cdn.com/20180805/1925294e2e9803ea1c1f43bfacc5b666.jpg
Again, the yellow boxes show the charge while driving. Not much action from the alternator.

https://uploads.tapatalk-cdn.com/20180805/2881b00d8c6f2e7bb7bf392049ce9f5e.jpg
This was the first day I noticed the alternator stop charging. It was a solid day of driving with some stops. All is well with the alternator until the time marked with the arrow.

Does it seem likely a new alternator is needed?

I have completed a hard reset following Tims (Traxide) advice but the alternator has not improved (Note - Tim answered his phone on a Saturday and was happy to give me advice - legend).

Lastly I have compared the battery recordings to direct voltage readings from an obd2 trip computer and they are consistent with each other.

Thanks in advance for any advice you can offer. I am currently in broome and can action repairs if necessary.

[drivesafe]

Hi Pawky, are you towing a caravan or camper trailer?

What dual battery kit is fitted?

Just guessing but was your July 20th graph taken just after you fitted the new cranking battery?

If so, then your voltage levels are actually quite good.

[Hugh Jars]

Hi Pawky, are you towing a caravan or camper trailer?

What dual battery kit is fitted?

Just guessing but was your July 20th graph taken just after you fitted the new cranking battery?

If so, then your voltage levels are actually quite good.

Tim, can you please explain (either here, or by PM) how to do the reset procedure, please? I have one of your kits (with the 160(?) relay box) and have just had a new starter battery at 18 months.

Thanks in advance [emoji4]

[drivesafe]

Hi Hugh, first make sure your PARK BRAKE light is off. This takes up to 3 minutes after you turn the ignition off and is an indication that your ECU etcetera, has finished their SHUTDOWN processes.

Then remove the negative ( - ) clamps from both batteries, and it does not matter which battery negative is removed first.

Now remove the AUXILIARY BATTERY positive ( + ) next.

Last, remove the CRANKING BATTERY positive ( + ).

I usually let them sit disconnected for a few minutes.

Then you need to hold the CRANKING BATTERY positive and negative CABLE CLAMPS together.

These two cables clamps usually will not reach each other, so get a JUMPER LEAD and join them together with that.

Just hold them together for a few seconds.

Now reconnect the CRANKING BATTERY positive ( + ) clamp to it's battery terminal.

Then reconnect the AUXILIARY BATTERY positive ( + ) clamp to it's battery terminal.

Reconnect the CRANKING BATTERY Negative ( - ) clamp to it's battery terminal.

Last, reconnect the AUXILIARY BATTERY Negative ( - ) clamp to it's battery terminal.

You will loos your TRIP meter readings but all else should be fine you start your motor.

When you start your motor, you might get some error messages. If you do, let your motor idle for a few minutes and then turn the motor off.

What till your PARK BRAKE light turns off and restart your motor and this time, all should be fine.

Also note, regardless of whether your USI-160 was on or off when you disconnected the batteries, it will now be off until you start your motor.

[pawky]

Hi Pawky, are you towing a caravan or camper trailer?

What dual battery kit is fitted?

Just guessing but was your July 20th graph taken just after you fitted the new cranking battery?

If so, then your voltage levels are actually quite good.

Hi Drivesafe
My dual battery kit is a Traxide SC80 that is approx 4 years old

The new cranking battery was fitted back in March, approx 4 months ago. It is a Varta Silver Dynamic.

None of the voltage charts I have shared are while towing. Looking at the graphs you can see the batteries are relatively low when I start driving but they don't really get an adequate charge.

Hope that helps clarify

Thanks
Pawky

[drivesafe]

Hi again pawky and from the saw tooth shape of the rested voltages in all the graphs, so I am guessing you have a fridge running all the time.

The voltage levels are fine, and you are getting in some major during times so once the cranking battery is fully charged, the BMS will lower the operating voltages.

On the 20th, you had around 8 hours of voltages at and above 14v.

This is easily enough to fully charge even low batteries, and charge them to well above 95% SoC.

Again, all looks fine, but what do you think you should be seeing?

[pawky]

Hi again pawky and from the saw tooth shape of the rested voltages in all the graphs, so I am guessing you have a fridge running all the time.

The voltage levels are fine, and you are getting in some major during times so once the cranking battery is fully charged, the BMS will lower the operating voltages.

On the 20th, you had around 8 hours of voltages at and above 14v.

This is easily enough to fully charge even low batteries, and charge them to well above 95% SoC.

Again, all looks fine, but what do you think you should be seeing?

Hi Tim

I agree on the 20th all was well until the time marked with the arrow.

Do the other 2 charts look normal to you? They are both more recent. In both I start driving with low SOC batteries but the alternator voltage never climbs very high. My batteries now seem to only get to approx 12.6 volts despite solid driving.

Thanks for taking the time to respond.

Pawky

[Konradical]

Pawky,

For my own interest, how are you recording these values and where?

[pawky]

Pawky,

For my own interest, how are you recording these values and where?

Hi Konradical

The images are from an app on my phone that links to a Bluetooth module connected to the aux battery. You can get them from super cheap auto or drivesafe also sells them.

Like this - Matson Bluetooth Wireless Battery Monitor - Supercheap Auto (http://www.supercheapauto.com.au/Product/Matson-Bluetooth-Wireless-Battery-Monitor/540712)

Hope that helps
Pawky

[Hugh Jars]

Thanks Tim for the info [emoji1303][emoji1303]

[drivesafe]

Hi Tim

I agree on the 20th all was well until the time marked with the arrow.

Do the other 2 charts look normal to you? They are both more recent. In both I start driving with low SOC batteries but the alternator voltage never climbs very high. My batteries now seem to only get to approx 12.6 volts despite solid driving.

Thanks for taking the time to respond.

Pawky

Hi again Pawky, first off, the high voltage time at the beginning of each day is sufficient to replace the bulk of the used battery capacity of the Optima and your cranking battery, but your voltage drops quite rapidly when the motor is off during the day, and each evening.

Can you post up what is drawing from the batteries while you are camped?

[pawky]

Hi again Pawky, first off, the high voltage time at the beginning of each day is sufficient to replace the bulk of the used battery capacity of the Optima and your cranking battery, but your voltage drops quite rapidly when the motor is off during the day, and each evening.

Can you post up what is drawing from the batteries while you are camped?

Hi Tim.

The only load is an Engel 60l and the usual opening and closing of doors. Our lights and second fridge run off our camper trailer.

Hope that helps
Thanks
Pawky

[drivesafe]

Hi Pawky, can you post up the graph for July 29 and August 3.

I can then see you usage a bit better then.

Also, any idea why you Voltage took a dip over a few hours, and then rose to 12.63v, a near fully charged battery?