Excitement in The Drovers Stable.........

[OLMATE]

Originally Posted by Jeeper6

As the battery reading is always on display I noticed it start to drop somewhere around Narrabri to 13.7v from the usual 14v. It was falling slowly over the next couple of hundred kms and seemed to settle around 13.2v...but did drop as low as 13v with an occasional 12.9v!

I panicked as I was deeply concerned that the Alternator was failing. I fired up the SRT gauges and they showed a similar story though a couple of volts higher than the Lufi on the dash readout.

I got to Bathurst ok and headed up the Mountain to set up the marquee. After that when i jumped back in and started it...started fine...the voltage rolled up to 13.9v, then flickered between 13.9v and 14.1v...ten minutes later it had dropped to 13.2v. Over the weekend it did that, though often stayed at 14v. I have no idea what this means...

Your battery is fully charged

Variable Voltage or ECU Controlled Alternators
Commonly referred to as “Smart Alternators”, these were introduced around 2010-2011 as a response by some vehicle manufacturers to help meet reduced emissions standards and provide better fuel economy. These alternators are controlled by the ECU to reduce the output from the Alternator once the starting battery voltage is back up to full charge after starting the vehicle. Once that voltage is reached, the output voltage of the alternator is significantly reduced (below 12.7V)

[FARWEST]

My 'interpretation' of the 14.3v-13vish variance is.......its a 'smart' alternator.....system tells alt 'all good' ,voltage charge rate drops to 13vish....start up n early running, or running after 'not being fully charged for some time', alt throws out 14vish charge into system as 'required' by ALL the li'l electrickery gizmos n devices.
Even my OLD cars had battery charge rate guages that would get up to as high as 16vish being thrown into it after a 'hard crank' (high compression engines take some winding over....and diesels fit that bill)...then the needle would drop to normal 13vish after 'the cob webs' were cleared out (read go pedal met floor for 'a bit').....rule of thumb was/is ? 40klmish(18 miles was my eleckies term) without droppin revs below 1500rpm and NO accessories on....not possible with all the gadgets on these rigs...so I do an 80klm loop @ highway speeds to throw enough charge into the battery to 'keep it happy'....it DOES work....I dont have any ability to read 'happiness'...just the 'feel' of the car n its gadgetry after the run.
Layback40.....a Battery Temp sensor !!!.....GEEZUS....I knew these rigs are 'over-monitored' as an over-ride in the event of a mindless nut behind the wheel, but....come on !

[FARWEST]

Originally Posted by OLMATE

Your battery is fully charged

Variable Voltage or ECU Controlled Alternators
Commonly referred to as “Smart Alternators”, these were introduced around 2010-2011 as a response by some vehicle manufacturers to help meet reduced emissions standards and provide better fuel economy. These alternators are controlled by the ECU to reduce the output from the Alternator once the starting battery voltage is back up to full charge after starting the vehicle. Once that voltage is reached, the output voltage of the alternator is significantly reduced (below 12.7V)

What he said...

[Jeeper6]

Originally Posted by OLMATE

Your battery is fully charged

Variable Voltage or ECU Controlled Alternators
Commonly referred to as “Smart Alternators”, these were introduced around 2010-2011 as a response by some vehicle manufacturers to help meet reduced emissions standards and provide better fuel economy. These alternators are controlled by the ECU to reduce the output from the Alternator once the starting battery voltage is back up to full charge after starting the vehicle. Once that voltage is reached, the output voltage of the alternator is significantly reduced (below 12.7V)

Yeah, i knew it was a "smart" alternator for the reasons you write. But it only just started to show dropping voltage...it has always sat at 14v - 14.1v on both gauges up to last week. The previous Jeep never ever wavered from 14v in the whole time I had it...that's what has thrown me.
The gauge is labeled a battery "condition" indicator, so it isn't an ammeter which would be showing the charge rate, hence my concerns.

That said, it does run up to even 14.3v after start and then might fall back over minutes to 13.7v, then down to 13.2v, even 12.9...which to me is a bit scary...

[drover]

Well I've gone over past data logs and I'm starting to get my head around this rigs charging regime, having data from previous times with the old battery the alternator set point charging rate was 14.1v, now with the new battery the set point has changed to 13.5v, will bring up to charge at 14 then drops back, so obviously the new battery has a set up which is different from the original and since the alternator doesn't need to be whacking in full charge all the time but drops down to keeping the battery at a level which for AGM's is deemed full charge I'm more than happy..... so a state of just over 13v is better than it trying to belt in 14v all the time and my alternator might be a lot happier especially the diodes, it may turn out the original algorithum for the thing is wrong and not so much the alternator,,,,,,,,,,,... because in the real world once you start the engine the drain on the battery should be zilch and the alternator should be carrying all the loads, if your battery has to donate then something in the power station is dicky, thats the same all over ................. Not having everything on auto and shutting down the AC each time you shut down the engine so its off when you start saves your battery just a little bit each time.... so on that very cold morning when you want every little bit of juice its there... having it on accessory so you can listen to the radio isn't a great help either on these electric everything things either.

Bloke pumping his tyres up coming off the beach down here, was miffed because his wagon wouldn't start not only running a compressor all the time, not shutting off between tyres he was running his Doof Doof full noise and the engine was shut down....... There are drivers and steerers, then I wonder at times.

The Grands don't have a smart alternator per se like some other vehicles............. operates more in line like the basic regulated set ups, thankfully.

[FARWEST]

The olmate with the doof doof n 'hold my beer' method of using a compressor after the beach, has shown me a new method....never have I turned mine off when pumping up the tyres BECAUSE the compressor was running, hence draining the battery/s....'all the gear no idea' rings a bell....jus sayin

[drover]

I'm waiting for beer oclock after cleaning my shed, was fiddling with a coolant drain hose and popped the drain tap knob off, hence a bit of a mess, hose was for ease of draining with bash plates still in place, it works with a bifg mental Note not to wind the knob too far................. Anyway nothing like a shower in the arvo, checked my old battery number with the online Mopar match up, it comes up as not suitable for my vehicle, 5033393AA instead it says I should have a BBAH8800AB, the paranoid would be having pinkies by now I suppose... both AGM's anyway .... I reckon if they fit they must be right...................... damn clock moves slow, might have to run the rest of the day on NZ time............