|
BRZ First-Gen (2012+) -- General Topics All discussions about the first-gen Subaru BRZ coupe |
|
Thread Tools | Search this Thread |
07-03-2018, 12:21 PM | #15 |
Member
Join Date: Feb 2017
Drives: WRB 2017 BRZ Limited w/ PP
Location: Louisiana
Posts: 97
Thanks: 2
Thanked 49 Times in 19 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
|
07-03-2018, 12:32 PM | #16 |
Member
Join Date: Apr 2018
Drives: 2018 Subaru BRZ tS
Location: Napa, CA
Posts: 77
Thanks: 3
Thanked 40 Times in 30 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
I have been watching the voltage meter recently. Most of time it is fairly stable at close to 14v, brand new car.
I plugged in a Kiwi3 OBD module for reading values on a smart phone. The voltage readout on the car instrument panel went spastic, dancing all over the place. Unplug the Kiwi - issues gone. I had one cycle right after unplugging it that it was still all over the place. The next cycle it quieted down to a more normal reading. I cannot tell you what is more accurate, Kiwi or car. The car display may have software in it that takes an average value, while the Kiwi is getting the raw information. This is all what I refer to as "Spurious Electrons", "Random Lines of Code" YMMV |
07-03-2018, 03:07 PM | #17 | |
義理チョコ
Join Date: Sep 2014
Drives: a 13 e8h frs
Location: vantucky, wa
Posts: 31,867
Thanks: 52,126
Thanked 36,517 Times in 18,919 Posts
Mentioned: 1106 Post(s)
Tagged: 9 Thread(s)
|
Quote:
__________________
|
|
The Following User Says Thank You to Ultramaroon For This Useful Post: | Last Lemming Alive (07-03-2018) |
07-03-2018, 05:51 PM | #18 |
Member
Join Date: Jun 2018
Drives: 2018 50th Anniversary BRZ PP
Location: US
Posts: 17
Thanks: 39
Thanked 20 Times in 9 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
BMW's efficient dynamics includes only charging the battery with the alternator when coasting, this is an article that explains it in much better detail (https://www.roadandtrack.com/car-cul...ns-bmw-n63-v8/) but it could be possible on newer cars Toyota/Subaru included this kind of charging system to help with fuel economy.
|
The Following User Says Thank You to dtbdan For This Useful Post: | Tcoat (07-19-2018) |
07-03-2018, 08:50 PM | #19 | |
Member
Join Date: Feb 2017
Drives: WRB 2017 BRZ Limited w/ PP
Location: Louisiana
Posts: 97
Thanks: 2
Thanked 49 Times in 19 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
Quote:
1 on decel was the car does indeed charge to 14v 2 the doesn’t start oscillating until it’s fully warmed up 3 while cruising the car reads just at 12.0V Question: 1 does the battery charge with only 12V? 2 if the gauge is showing 12V does that mean the rest of the cars systems are gettting enough Volts to keep things running? For instance the A/C, I the computer etc and still have enough to charge the battery? Or will it drain the battery if I should go on a long trip and don’t have the opportunity to coast. |
|
07-03-2018, 09:18 PM | #20 | |
Member
Join Date: Jun 2018
Drives: 2018 50th Anniversary BRZ PP
Location: US
Posts: 17
Thanks: 39
Thanked 20 Times in 9 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Quote:
|
|
The Following 2 Users Say Thank You to dtbdan For This Useful Post: | Last Lemming Alive (07-03-2018), Ultramaroon (07-03-2018) |
07-05-2018, 08:53 PM | #21 |
Senior Member
Join Date: Jun 2014
Drives: swp mt '14 brz premium
Location: 20872
Posts: 166
Thanks: 2,195
Thanked 111 Times in 75 Posts
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
|
constant 14v
I sourced my voltage gauge at the glovebox power plug. With key on and engine off I get a hair over 12v usually. With engine running it stays at 14v.
|
07-05-2018, 09:15 PM | #22 |
Senior Member
Join Date: Nov 2017
Drives: 2017 Subaru BRZ PP WRB
Location: Gulf Coast
Posts: 383
Thanks: 71
Thanked 206 Times in 128 Posts
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
|
I found this info in an information guide regarding changes to the 2017 BRZ:
Battery condition sensor: The previous (2016 and older) current sensor always maintained control to keep the battery fully charged. The (2017) battery condition sensor calculates the charge status, level of deterioration and internal resistance of the battery from data such as its voltage, current and temperature, and controls charging so that there is always spare capacity available. This allows the recharging rate to be increased when decelerating, which improves fuel efficiency. |
The Following 3 Users Say Thank You to NCtoBRZ For This Useful Post: |
07-18-2018, 02:04 AM | #23 |
Member
Join Date: Apr 2015
Drives: 18' 50th An. BRZ, 79' RX7
Location: Los Angeles, CA
Posts: 24
Thanks: 47
Thanked 30 Times in 13 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
I think it’s normal. I’ve noticed my ‘18 BRZ (completely stock, 1600 miles) fluctuate between 12 and 14- not sure if I’ve noticed a pattern to it while driving though.
It was really obvious when I was sitting parked with the ac on on a hot day- when the radiator fans would turn on, the voltage would rise to 14v (the charging system compensating for the extra load). Fans turn off, back down to 12v. This slow oscillation continued while I remained parked. |
07-19-2018, 08:43 AM | #24 | |
Member
Join Date: Feb 2017
Drives: WRB 2017 BRZ Limited w/ PP
Location: Louisiana
Posts: 97
Thanks: 2
Thanked 49 Times in 19 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
Quote:
|
|
07-19-2018, 09:38 AM | #25 |
Senior Member
Join Date: Jul 2014
Drives: 2020 Hakone
Location: London, Ont
Posts: 69,845
Thanks: 61,656
Thanked 108,283 Times in 46,456 Posts
Mentioned: 2495 Post(s)
Tagged: 50 Thread(s)
|
It is indeed something new to the 17s. Was one of the many changes.
What is happening is explained well in the update document.
__________________
Racecar spelled backwards is Racecar, because Racecar.
|
The Following 2 Users Say Thank You to Tcoat For This Useful Post: | jcw99 (07-23-2018), thomasmryan (10-01-2019) |
09-30-2019, 02:30 PM | #26 |
Member
Join Date: Aug 2019
Drives: 2017 86
Location: TATOOINE
Posts: 10
Thanks: 0
Thanked 4 Times in 3 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Subaru stupidly programmed the car to let the battery discharge during acceleration a
Starting in 2017 forward, Subaru stupidly programmed the car to let the battery discharge during acceleration and stops, doing most of the charging while decelerating only. I discovered this when I parked to listen to the radio for an hour and the car would barely crank. They said it's for "economy" B.S.! This will ruin batteries faster. You can force the car to "normal charge" at 14.2V by turning on the running lights (I drive with them all the time now). Also, if you turn the fan on it will hold at 13.3V. But drive normally and watch the voltage drop from an initial 14.4 at start to around 12.1 in just a few minutes. More on this later as I'm working up a big expose.
I'm an Engineer, I like to measure things. |
The Following User Says Thank You to ROGER-86 For This Useful Post: | Plumbus (03-21-2020) |
09-30-2019, 02:39 PM | #27 | |
Senior Member
Join Date: Jul 2014
Drives: 2020 Hakone
Location: London, Ont
Posts: 69,845
Thanks: 61,656
Thanked 108,283 Times in 46,456 Posts
Mentioned: 2495 Post(s)
Tagged: 50 Thread(s)
|
Quote:
__________________
Racecar spelled backwards is Racecar, because Racecar.
|
|
02-12-2020, 08:45 PM | #28 |
Member
Join Date: Oct 2018
Drives: Toyota 86 Special Edition
Location: Los Angeles
Posts: 26
Thanks: 0
Thanked 4 Times in 4 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Having this same issue with 2017 GT86. But notice that it is also dropping when braking. I would have thought that would be a charge zone! The car is also having trouble starting. I had to charge the battery last night.
I've checked the battery and it's at about 12.4 - 12.8. I've checked for drain when everything is off. And it drops to .01 A. So it doesn't seem like it is losing power at night. The car/battery is only 2 years old. So I would not suspect it is going and that is causing the extra problems. But, I have seen posts about older FRS/BRZs where the factory battery doesn't last long. It takes a charge and gets to full charge pretty quickly. Then it seems to hold it - until it doesn't. I'll keep trying to see if I can determine any patterns. But, I thought I'd see if 12V while braking is not a design feature. Anyone? Last edited by Jay Laifman; 02-12-2020 at 10:57 PM. |
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
O2S2 Voltage Always Zero | bhaugen2 | Engine, Exhaust, Transmission | 22 | 09-14-2022 05:35 AM |
What battery ecu voltage are you getting with torque | pcguru2000 | Issues | Warranty | Recalls / TSB | 8 | 05-08-2018 08:53 PM |
Voltage Fluctuation | Andrew666 | Electronics | Audio | NAV | Infotainment | 5 | 04-21-2013 08:15 PM |
Voltage fluctuations | Andrew666 | AUSTRALIA | 7 | 03-19-2013 09:44 AM |