The Automotive Thread

[MetsFan]

2 hours ago, MetsFan said:

I bought a battery at Advance Auto Parts with a coupon last month for $130.  BMW wanted $240 for the BMW branded one.  I haven't put it in yet though but other people have had good luck with them.  I just have to figure out how to register the battery.  I have the PC to OBD cable, but it's a mess of software I have to figure out.

Regarding consumer reports, do a google search for: consumer reports library login.  If you have a library card, you should be able to get in too.

Register the battery....I never heard of such a thing.  A quick search found that ther are tons of opinions on this BMW requirement.  The vast majority say BMW wants $150 on top of hte battery cost to register.  Most of the threads said the registration is BS.

You learn somehting new everyday.

Yeah, it's a crap shoot. It has to do with adjusting the charging based on how old the battery is. The new battery is pretty much the same as the old one so they say it's just a formality, but I figure it's better to be on the safe side.

 

[MetsFan]

Not to change subjects, but I have a Subaru with a head gasket slow oil leak.  Any idea what the cost might be (non dealer) to change the gasket?  I fear this one is gonna hurt. 

Wow, it looks like upwards of $1200... The parts are only $100.

 

[Ship Wreck PE]

How do you know that the gasket is the only problem?? Warped head, Cracked head, Cracked block, burnt valves, Busted Pistons. Once you bust it open it could get real expensive??

 

[Supe]

I wasn't planning on cheaping out.  I was planning on spending $100 plus for a decent battery.  I was talking more about sprinting for an Optima Red or Yellow top battery.  Is it worth the extra $50+ for those unless I'm driving something in addition to the car (i.e., a big stereo)?  I kinda got screwed last time I replaced the battery.  I took my car in for a 60,000 mile tune up.  I knew the battery was shot, suspected my brake pads were completely worn and wanted the belts and other consumables checked.   The shop I took it to only charged me about $50 for diagnostics, $30 for new belts, and $75 for a new battery and told me my brake pads were fine.  But since I had them replace the battery, I really didn't get a choice in what brand I got.  I ended up with an Exide cheapy that is now dead again.  Other than that, the shop earned my future business by not replacing everything possible and charging me $1000+.

Stay the hell away from Optima!  No BS, even BEFORE the quality allegedly "went down the tubes", I replaced SIX, yes SIX Optima Red Tops under a SINGLE warranty in the race car.  One complete discharge and they were done, there was no bringing them back to life despite any of the tricks or chargers.

Without a doubt, the absolute best wet cell batteries I have ever used are the Duralast Gold from Autozone.  I don't know what it is about them, but you can't kill them.  I had my big 950 CCA mother discharged completely a good 4 or 5 times, and it still came back to life every time.  

 

[wilheldp_PE]

Out of curiosity, why are race cars a special case for batteries?  When I was looking at reviews, the two special cases they listed were car stereos and race cars.  Do race cars not have an alternator?

 

[Supe]

A lot of race cars will run with no alternator, and will draw much higher starting currents due to the high compression, large displacement motors taking a lot more oomph to turn over.  The trick I used to do to help with the latter was to spin the motor over with the ignition off, which keeps cylinder pressures down during cranking (most guys will lock their timing out with a higher level of advance, often 20+ degrees higher than stock, which makes it not want to fire until you get some speed in the rotating assembly).  You then light it off by flipping the switch for the ignition box when the motor is already spinning.  

 

[MA_PE]

Supe:  It's my understanding that auto batteries don't like to discharge completely, aren't you better off using a marine-type deep cycle battery if you're going to discharge it semi-regularly? 

 

[Supe]

Supe:  It's my understanding that auto batteries don't like to discharge completely, aren't you better off using a marine-type deep cycle battery if you're going to discharge it semi-regularly? 

Yes.  In my case of the 6 ****** red tops, I was running an alternator.  The battery was discharging/dying while sitting over a one and a half to two week span with no drain on the battery (disconnect switch).  

For the guys that run no alternator, they typically will run either a pair of 12v batteries or a single 16v battery and charge between rounds.  

 

[Ship Wreck PE]

I have 2 blue top Optima battery's in my boat and they have been fine for 5 years.

 

[MA_PE]

Yes.  In my case of the 6 ****** red tops, I was running an alternator.  The battery was discharging/dying while sitting over a one and a half to two week span with no drain on the battery (disconnect switch).  

For the guys that run no alternator, they typically will run either a pair of 12v batteries or a single 16v battery and charge between rounds.  

what would cause a battery to discharge with no draw?  Especially in 2 weeks?  Hmmmm.

 

[Flyer_PE]

what would cause a battery to discharge with no draw?  Especially in 2 weeks?  Hmmmm.

A circuit path internal to the cell.  My bet would be a manufacturing defect if the battery is fairly new.

 

[Supe]

It baffled me.  The only thing I can figure is that it was receiving a slight overcharge, and that was causing the battery to deteriorate.  My understanding is that AGM batteries are very susceptible to premature "drying" of the mats during an overcharge situation, which can be as little as a tenth of a volt.  So if we were charging at 14.8-14.9v, that can start to wipe them out ahead of time.  

 

[Supe]

A circuit path internal to the cell.  My bet would be a manufacturing defect if the battery is fairly new.

Wouldn't surprise me.  I believe this was 6 batteries of the same make/model in less than three years.  Duralast gold with no other changes in that car will still take a charge after 5 1/2 years...

 

[Flyer_PE]

It baffled me.  The only thing I can figure is that it was receiving a slight overcharge, and that was causing the battery to deteriorate.  My understanding is that AGM batteries are very susceptible to premature "drying" of the mats during an overcharge situation, which can be as little as a tenth of a volt.  So if we were charging at 14.8-14.9v, that can start to wipe them out ahead of time.  

AGM cells are in fact sensitive to charging voltage.  For a 12V battery, there are 6 cells internal to the case.  If one of them starts to short internally and drops voltage, the charging voltage for the other 5 will increase (charging voltage for the battery remains constant).  The higher charging voltages will accelerate the aging process for the affected cells.

 

[Dexman PE PMP]

Explains how my cell phone battery is fine for a while, but when it starts to go, the deterioration accelerates quickly.

 

[DVINNY]

I agree with RG above, two weeks ago, I had to get a new battery for the Trailblazer.  The one that was in it was bought in 2007.  I went to Advance Auto and bought the same one.  Figured if the last one lasted that long, it was good to go.

Funny part is, the guy at Advance Auto kept telling me that they didn't have the battery I needed to "fit" my vehicle and that they could order it.  I said, "I want this same battery, and you have it on the shelf over there" he said, I understand that we have that one, but the computer shows that it doesn't fit your vehicle.  I said "fine, I'll buy it anyway"  he said, "but I'm not sure if it will work".   I then paused for a bit, once he looked up at me, I said "buddy, I just took this one same old one out of that vehicle and it has worked fine in it since 2007.  I think I'll be OK".

I don't think he ever did 'get it'.  I believe once I left he was probably shaking his head saying "I warned him the computer said it wouldn't work".

 

[matt267 PE]

I agree with RG above, two weeks ago, I had to get a new battery for the Trailblazer.  The one that was in it was bought in 2007.  I went to Advance Auto and bought the same one.  Figured if the last one lasted that long, it was good to go.

Funny part is, the guy at Advance Auto kept telling me that they didn't have the battery I needed to "fit" my vehicle and that they could order it.  I said, "I want this same battery, and you have it on the shelf over there" he said, I understand that we have that one, but the computer shows that it doesn't fit your vehicle.  I said "fine, I'll buy it anyway"  he said, "but I'm not sure if it will work".   I then paused for a bit, once he looked up at me, I said "buddy, I just took this one same old one out of that vehicle and it has worked fine in it since 2007.  I think I'll be OK".

I don't think he ever did 'get it'.  I believe once I left he was probably shaking his head saying "I warned him the computer said it wouldn't work".

Must have been a millennial.

 

[MA_PE]

DV:  I ran into kind of the same thing when i recently bought a battery at Interstate.  The guy looked it up and brought me the recommended battery.  I had the dead one with me and they weren't the same size.  I bought the same size as the one I had just removed.  The Interstate guy didn't question it at all, just that the case foir the one in his reference table was not the same case as the one I removed from the car.

 

[DVINNY]

Must have been a millennial.

Yup,  and should get at least $15/hr and his school loans paid off because he deserves it.

 

[Dexman PE PMP]