05 STS battery...again

Wiring, DIY, lighting, etc.
kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Sun Feb 09, 2020 9:47 pm

First I tested it with the charger still connected after it was done. 7:45pm
20200209_194558_HDR.jpg
Then I disconnected the charger and tested it again. Notice the surface charge but, uh oh, replace? 7:47pm
20200209_194742_HDR.jpg
Then what I did was leave the tester connected to run the backlight and hopefully drain off the surface charge. That took a while. 8:15pm
20200209_201517_HDR.jpg
Again at 8:34pm
20200209_203427_HDR.jpg
Again for the last time before connecting the cables back, 9:17pm.
20200209_211757_HDR.jpg
Then just to prove this cheap tester is not adequate for testing when connected to the car, I connected the cables and re-ran the test. Yeah, that's not correct.
20200209_212116_HDR.jpg
Got in the car and started it. Starter seemed closer to what it should be. Car started charging at like 14.4 to 14.5V right away which was a good sign. After no more than 5 minutes of idling it had tapered off to 13.3V. I shut the headlights off and as expected, it tapered further to 12.9V. This is exactly how the FSM says it is supposed to work.

Side note, the new firmware grabs GPS time as soon as it is able so the clock was right immediately. Most settings seemed untouched. It lost track of tire pressures and reset all my fuel economy stuff (my Boston trip!).

I am curious with a full reset if it will at least keep this battery better topped off. However, it seems to be compromised at this time. Whether it is the car that caused it, or it is just a defective battery, I really can't prove it one way or the other. I think I will likely shoehorn a Group 78 AGM in here at some point but I may also run this battery until well into next fall, depending.

The good news is, my ears don't lie. So I can probably gauge from the starter sound if it is getting weak.

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Mon Feb 10, 2020 7:29 am

13.3-13.4V the whole ride in. Starter sounded decent this morning (not labored). Won't know if resetting everything made a difference until the week plays out. Of course now I know the battery is compromised.

Maybe maintaining power to change the battery originally back in August is what killed it because the smart charging system miscalculated amp hours or whatever so it was never charged properly? Or it is defective. Or there is an intermittent draw which would also be hard on the battery, although the kind of draws I am familiar with tend to result in the car either barely starting or not starting at all - not the case here.

It is odd to discover what resets and what doesn't when the battery is disconnected. It was disconnected for probably 8 hours, and I even shorted the positive and negative together with a wire, as well as checked the voltage on the cables, and I think power was totally drained.

Things that reset:
- Within the DIC: Average MPG, gallons used, average speed, TPMS sensors lost sync (regained it this morning with no issues)
- Possibly the HVAC. It was 75F and A/C engaged which I don't think is how I had it set before.
- The auto up on all four windows needs to be reset (standard procedure)

Things that didn't seem to reset:
- Trip odometer
- Check engine light (!)
- All of the navigation settings. In fact, they all reset when I updated the firmware but NOT when I disconnected the battery! Even my phone BT pairing stayed. The clock came back a minute fast (vs my phone) and then after maybe 60 seconds, flipped back on its own 1 minute to perfectly match my phone. I didn't do anything except go into the menu and look. I never pressed sync to GPS, so the new firmware does this automatically now. Fancy. The CTS-V can also sync to GPS but it is fully a manual process. The SRX clock is analog and needs to be set on its own.
- Radio settings, EQ (probably - didn't check). It was still set to Aux in as I had left it. I'm sure it would have kept the radio presets if I had any.
- All my memory/personalization settings (which are managed through the nav). Seat, mirrors, power tilt/tele steering wheel stuff. None of that changed.

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Tue Feb 11, 2020 6:37 am

So for a few minutes each cold start, it seems to be charging and then it tapers off pretty quickly. But before, it wasn't even doing that, it was cold starting right into voltage reduction mode.

This small change could be a result of resetting everything. The question is, what happens over the next week? We will see.

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Tue Feb 11, 2020 6:59 pm

Still charging for a few minutes and then tapering off. It even did it off a warm start which makes sense to me. It needs to charge from the crank cycle. This seems to be doing what it is supposed to do, unlike before.

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Wed Feb 12, 2020 6:37 am

So I picked Ian up last night from an activity and the drive home is fairly short so I noticed it was doing like 14.2-14.3V the whole time. I took that to mean it did not fully charge the battery after the warm start. If that was true, I theorized I would see extra charging this morning to make up for the fact that it did not reach 100% last night. Sure enough that's what it did. This morning it charged (~14.3V) for a good 15 minutes.

I'd say the charging behavior now meets my expectations so maybe I can nurse this battery along until late fall next year. Kinda sucks because I'm still wondering if having it never really charge properly (because I maintained power on the car while changing it in August) caused its early demise.

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Fri Feb 14, 2020 7:09 am

It's Friday. Been ~5 days since I reconnected the battery. This morning it was around 28F. I expected a somewhat slow crank. However I am pleased to report that it cranked quite well.

Seems to me that I have resolved the issue, and it is still entirely possible that:
A) I don't have a big draw
B) Changing the battery while keeping the car powered resulted in an improperly charged battery, which has probably damaged it over a period of months.

I'll keep monitoring (I drive around with the DIC set on voltage so I can obsessively look at it). It finished charging a little over halfway to work, maybe 15 minutes again. The behavior has been consistent and inline with expectations.

But this also means the battery has given up a substantial amount of its reserve capacity if Adam's tester is accurate. I suspect I can easily make it to next ~November or even December but I do need to remember that the battery is compromised. I don't want to run it as long as I ran the last one, where just playing some music for a few minutes resulted in a complete no start (Bob remembers).

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Sat Feb 15, 2020 4:49 pm

I tried 2008 and went into the IPM. All it told me was this, under load management:
20200215_161628_HDR.jpg
Turns out this is also available under 2005. So that didn't buy me anything but at least I can get calculated temp and current.

Just in case I want to revisit, here are the software numbers that I could use to see if I have the most up to date firmware:
20200215_162205_HDR.jpg
Incidentally after about 15 minutes of idling, it started to taper off charging, just like if I was driving to work.
20200215_163001_HDR.jpg
The only other thing I could do is compare with my clamp on meter but I bet this is accurate and working fine.

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Tue Feb 18, 2020 7:23 am

Car sat since Saturday (at least I think - I can't remember anymore). Cranked normally this morning in like 28F, charged for ~15 minutes per usual. I don't think I have a draw.

This has been interesting. Good thing I didn't pay for this battery...

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Thu Feb 20, 2020 7:06 pm

I have officially switched the DIC back to average MPG (from voltage). So this is fixed. Until this battery falls below some threshold and needs to be replaced again. But at least it is charging properly.

kevm14
Posts: 13935
Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS battery...again

Post by kevm14 » Fri Mar 27, 2020 4:02 pm

Granted it was 55F at the time but the STS cranked perfectly today after sitting since last Wednesday (approx 8.5 days of sitting). I was already pretty convinced but this is more evidence that I don't have a draw and that resetting the car cured the charging issue I was having.

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