12v Battery Is Discharging, Re-Charge Now !

take it in, tell them it is losing a volt per night. have them measure it with you, and again in the morning. if they balk, call toyota corp and open a case

 

Ah a newbie.

 

I notice a motor (brake boost?) sound only after opening a door. The interior lights illuminate every time the fob comes close to the vehicle. No motor sounds just coming close have been observed by me.

 

Yesterday, my wife noticed motor sound coming out my PRIME. She asked me why my car was on. (But the car was not on.) She did not have a fob with her, and I did not get close to the car either. Besides, my car's fob seeking beacon has been inactivated, so even if I come close to the car with a fob, it will not turn on the internal light. I think I have heard similar motor noise which was more like compressor fan (not the brake booster sound you hear each time you open the door or depress the brake pedal) in the past too, but have no idea what it is and when it gets triggered.

 

Most current Toyota’s do fuel system pollution maintenance eg. purge the carbon canister. It’s documented in a paragraph buried in the manuals.

 

Yes, I am aware of that functionality. But the sound was coming from the front under the hood.

Not exactly sure if that would be called "under the vehicle". Plus, the manual says nothing about how often it operates or what the sound is like. The car has been parked for the last 4 days without driving. If the sound I heard was in fact the fuel evaporation leakage check, then I still wonder what triggers that check.

 

...but IBM Z wasn't introduced until 2009?

Cobol? ...if so, you have become valuable ;-)

fwiw, in my case it was Basic, then database... dBase, FoxBase and all versions of FoxPro all PC. In my case, I'm too dyslexic to switch between other languages.

Beverly Howard

 

Assembler, COBOL, FORTRAN. Entered IT in ‘69 on a 360-30. Retired 5 yrs ago after supporting MVS->zOS as a Systems Programmer. Assembler and Rexx mostly towards the end.

 

APL was a lot of fun

 

Once you get past the keyboard.

 

Here is another summary of various parameters I tested to see the effects on 12v SoC in addition to what has been described in my previous summary in comment #217.

Three parameters I checked are 1. charge schedule, 2. OBDII adapter, 3. SKS key fob monitoring setting

• using an external charger to fully charging the 12v battery result in SoC (~13v) which seems to maintain the 12v SoC stabilize at around 12.5v after 5 days up to 13 days I charged again. This is a substantially longer period that the 12v battery SoC stays above 12v than just driving ~1.5 hours once a week to charge the 12v battery.
  
• with charge schedule ON, OBDII adapter in place, and SKS monitoring for the key fob set to stop after 5 days (default setting), first 24-48 hours 12v battery drains ~0.15v/day
  
• with charge schedule deleted, OBDII adapter in place, and SKS monitoring for the key fob set to stop after 5 days (default setting), first 24-48 hours 12v battery drains ~0.15v/day
  
• with charge schedule ON, OBDII adapter removed, and SKS monitoring for the key fob set to stop after 5 days (default setting), first 24-48 hours 12v battery drains ~0.20v/day
  
• with charge schedule ON, OBDII adapter in place, and SKS monitoring for the key fob set to stop after 0 days (by CARISTA), first 24-48 hours 12v battery drains ~0.15v/day

I am charging the 12v battery now. After it is fully charged, I will check on more time for all three parameters adjusted to charge schedule deleted, OBDII adapter removed, and SKS monitoring for the key fob set to stop after 0 days (by CARISTA). But I have a feeling those three added together still have no effect on the initial 12v battery drain. I will see.

 

Gotcha. A Memory Saver maybe can help with that. I lay my jump pack in the driver's footwell, and run a memory saver cable (purpose-built for that use, with indicator light to verify connections) from the jump pack to the OBD port. The cable's obd connector has only the pins needed for supplying 12 volt.

I believe that's the route I went when I disconnected ours to test the milliampere draw. at the 12 volt, but it's quite a ways back. Having the memory saver connected might muddy the water though, skew the test? Not sure.

 

I did order a memory saver cord and AC/DC converter to attach the memory savor in case I have to remove the 12v battery. I would only need to attach this while I connect and disconnect the multimeter in series, so during the amp draw testing, the external source of 12v would be removed, if I understand it correctly. Yeah, I was hoping I did not have to disconnect the 12v to find out a single culprit that is draining the 12v battery, but I may have to do the amp draw test after all. I was just notified from my work that I am going to continue working from home at least for the month of July and possibly longer.

 

I use this:



plus either of these (have a couple):

 

wow, you folks are taking it to the 12v battery house!

i'll stick with doing nothing and replacing it every 7 years

 

Yeah, that's what I would have done if I am driving to work every day. The 12v in my old HCH lasted 10 years that way.

 

Well the above is not direct battery maintenance, just trying to see what background load is being imposed on the battery. Hey, we got nothing else going on.

 

i hear you

 

OK, my PRIME's 12v battery is now fully charged up. I have deleted the charge schedule, removed OBDII adaptor, and SKS sensor not to monitor the key fob. I will see if this reduces the initial drain. After this experiment, I will try setting up the amp draw test maybe this weekend.