Repair-It

kevm14 wrote:So more battery observations. I've had Ed and Adam tell me they'd just replace the battery and not screw around. A group 101 is like $200 for this car, less from certain sources. So I want to milk it if it's not totally and obviously about to render the car inoperable.

So it's time to replace. Brought the old battery to WalMart and put it next to their group 78. Too tall. Some folks report some group 78s fitting but I don't have time to play battery measurements. I decided to get the correct group 101 from Advance, from their Gold line. Online they have a 20% off coupon and combined with another $20 Speedperk, minus the core, I walked out with the right OEM size battery for $147.22 with tax. Not bad at all compared to $200+.

Fun facts.

Old battery. Interstate! WTF, Saudi Arabia? New battery. Saudi Arabia again?? Same factory then? Wonder where the AC Delco is made...

Oh yeah, I had them test the old battery for S&G. Pretty failed. If you go by this, it was at only 11.5% of rated capacity. I don't know how long it's been on the shelf so I think I will throw my Battery Tender on it one last time before I put it into official service. I want to see how much better it cranks.

One other fun fact. While the battery was disconnected I couldn't get into the front doors or trunk. How many cars still have key lock cylinders for the rear trunk or hatch though?

I left it on the Battery Tender for a while. Might have been 6 hours. The charger was extremely hot, though I can't say for sure that is abnormal. The battery voltage while charging was only 12.9V and the red light was still on solid. No idea how much longer it would have needed but the alternator can do better. So I decided to unplug it. The resting voltage only dropped to 12.7V. I took it for a spin and I don't think it actually cranks any faster than before, but I didn't think it was cranking slow before, either (miraculously). I'll be curious if it drops to 13.0 on my commute tomorrow morning or decides the battery isn't done charging yet. When I drove it just now it was around 14.4.

It stayed charging at 14.2-14.4V the entire drive. Which means it probably was not that charged sitting on the store shelf.

I was reading about batteries over the weekend and some BMW people were talking about switching to an AGM battery and how you have to go to the dealer to get the car reprogrammed to properly charge one. So I guess these fancy systems are actually trying to properly charge batteries, rather than the old school of just throwing some voltage above 12.8 for however long the car is running. Which means I probably should have just installed the battery and left it alone rather than trying to charge it. I mean the system knows voltage and how much current is going into or out of the battery. It could use that to determine state of charge perhaps more actively than just sheer calculations.

Same deal on the way home. 14.2, never dropped. It very well may be that the computer read the old battery as topped off when the actual state was "couldn't take much of a charge."

This was the first time I commuted in the STS after driving the CTS-V all last week. Verdict on switching back? I like it just fine. I never have an expectation that it is supposed to handle like a sports car but knowing it is 4,2xx lbs, I think it drives very well. The powertrain is pretty well calibrated as a pair. I challenge anyone who hates automatics to drive this and tell me this doesn't just get out of your way and be in the right gear at the right time.

Still wanting more from the brakes. But I took it down a curvy back way on the drive home and put the suspension in Performance. It was plenty capable though again the feeling is more of comfortable speed and competence than outright playfulness. Put another way, I don't think anyone would drive the car and think "I expected better handling from this." The steering definitely has a feeling where it wants to drive straight ahead, which is why it's so nice on the highway. It feels plenty solid, composed and still compliant in turns but doesn't really live for the turns, if that makes sense. The confidence is there - it drives lighter than it is. Maybe it's just the way the steering is weighted. I bet the all season Continentals play a distinct role in the feel here, but I wouldn't run the PSS on this so whatever.

EDIT: I also pitched it into corners pretty hard and nothing glitched. So hopefully water is no longer where it is not supposed to be and hopefully it suffers no ill long term effects.

Still 14.2V when I pulled into my parking spot. I wonder if it would do anything different on a longer drive. I bet the old battery was taking no significant current leading the computer to perhaps assess that it was actually over charged, not just charged, and back off the voltage to 12.8-13.0. That must not be normal behavior.

When I got home I opened the hood to look at stuff and decided to start the engine with the hood open. The DIC flashed a message after it told me the hood was open.

It said:

Speed limited to 155 MPH

Discuss.

What is the limit with the hood closed?

I don't know. Research is also unclear. Mine may not really have a limiter, or it may hit a drag limit a little before any actual speed limiter. I don't know if it can actually hit 155 on flat road.

The general consensus is it is just based on the original tires. I can check my sticker and see what speed rating the original tires had and that likely drives the speed limiter. I guess that makes sense.