Q5 aftermarket battery options?
07-20-2017, 12:51 PM
#21
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Variable alternator output for better mpg? That's interesting, and even logical. Once the computer power is cheap enough so that this kind of housekeeping can be run without impacting anything else, I guess that makes sense. But even the 1970's Delcotron's had that much sense. They always put out 14.3-14.4 volts, they simply changed their output pulse rate in a range from something like 100Hz to 10,000Hz, just tickling the battery constantly to keep a full charge on it. Swinging the entire system voltage over a much wider range...almost sounds like some engineer took up a dare. Or a double-dare.
I suppose there must be something somewhere that goes into these things, but modern charging logic somehow isn't on the Times Best Seller list. Or at the corner coffee & book store.(G)
I suppose there must be something somewhere that goes into these things, but modern charging logic somehow isn't on the Times Best Seller list. Or at the corner coffee & book store.(G)
Go on a long, highway road trip with a car that actually displays charging voltage, and you can kinda get a simplified glimpse of some of the charge logic in action. Initially, you see the battery being charged, but then somewhere down the road the alternator scales back and it runs mostly on battery for better efficiency. Repeat cycle for 20 hour road trip
Add in stop and go, A/C cycling, and other variables, and it gets tough to tell why and what is going on, but it seems to work
07-22-2017, 07:24 PM
#22
AudiWorld Super User
Zig-
Short answer, yes. In theory the key can be off, since those posts are there to jump start a dead car, and some folks do jump starts with the key OFF, just in case the "donor" blows the electronics in the dead car.
Just remember OZ the All Powerful is hiding in there, and may find some way to exact petty vengeance because he wasn't informed of the change.
Black- You're right. Voltage-based charge systems have been obsolete for over a decade, the key factor is really what amperage are the batteries accepting. But then things get complicated, as any kind of "current monitor" or power monitor in a charging system REALLY needs a reality check and recalibration from time to time, annually at least, or it gets out of sync with the battery. A good one will be designed so that when it gets out of sync it will think the battery is deader than it is...but still, none of them can really work with adult supervision from time to time.
I think the A8 and R8 are supposed to have water-cooled alternators in them now...what's that line from the movies?
"Be afraid. Be very afraid."
Short answer, yes. In theory the key can be off, since those posts are there to jump start a dead car, and some folks do jump starts with the key OFF, just in case the "donor" blows the electronics in the dead car.
Just remember OZ the All Powerful is hiding in there, and may find some way to exact petty vengeance because he wasn't informed of the change.
Black- You're right. Voltage-based charge systems have been obsolete for over a decade, the key factor is really what amperage are the batteries accepting. But then things get complicated, as any kind of "current monitor" or power monitor in a charging system REALLY needs a reality check and recalibration from time to time, annually at least, or it gets out of sync with the battery. A good one will be designed so that when it gets out of sync it will think the battery is deader than it is...but still, none of them can really work with adult supervision from time to time.
I think the A8 and R8 are supposed to have water-cooled alternators in them now...what's that line from the movies?
"Be afraid. Be very afraid."
07-22-2017, 08:16 PM
#23
AudiWorld Super User
For questions in most recent few replies:
Also from earlier, I actually suspect the system does eventally learn effectively there is a new battery even with no replacement coding. Not logical to me just from common sense it only "learns" in one direction as battery ages. Only contra to that that occurs to me is really a time based deterioration algorithm, which I haven't heard they use. Said another way, with a lot of D3's now well over 100K miles and 10 years--where this monitoring system first appeared--I don't think anyone who just dumped in a new battery with zero recoding ever ended up with an issue of any sort, let alone some nightmare scenario. Folks have also installed AGMs without issue, though the OE fitment or what dealer would sell you for that model is still the older wet style.
Yes, Audi A8's have had water cooled alternators since at least D3. They rarely seem to fail--either electrically or with the cooling lines/circuit.
I would not hook a charger to car when swapping battery. Just disconnect and replace. Starting with my 2006 A8 (following a prior generation 2000 C5) about all I would lose programming wise was the date--not even the time was lost. Days of reprogramming radio presets, seats, keys, etc, should be over. You do have to run windows full down, full up once to reset the one touch and overlapping pinch safety function. It needs to relearn the stop point.
Reaching back earlier, I don't recall that batteries sold at US dealers are actually Euro. They have the coding sticker on them, but as explained you can just augment code by one digit and fake it out. As also stated, probably 90% plus of all batteries out there in US channels come from one of East Penn/DEKA, Exide or Johnson Controls. There are different quality levels, plus AGM or older conventional. Audi has shifted to AGM on recent generation models in general. I think Audi US ones are commonly Johnson Controls. BMW/Minis when I last had one were Exide--as I found when I peeled their label off and found the Exide one directly underneath. I would not hook a charger to car when swapping battery. Just disconnect and replace. Starting with my 2006 A8 (following a prior generation 2000 C5) about all I would lose programming wise was the date--not even the time was lost. Days of reprogramming radio presets, seats, keys, etc, should be over. You do have to run windows full down, full up once to reset the one touch and overlapping pinch safety function. It needs to relearn the stop point.
Also from earlier, I actually suspect the system does eventally learn effectively there is a new battery even with no replacement coding. Not logical to me just from common sense it only "learns" in one direction as battery ages. Only contra to that that occurs to me is really a time based deterioration algorithm, which I haven't heard they use. Said another way, with a lot of D3's now well over 100K miles and 10 years--where this monitoring system first appeared--I don't think anyone who just dumped in a new battery with zero recoding ever ended up with an issue of any sort, let alone some nightmare scenario. Folks have also installed AGMs without issue, though the OE fitment or what dealer would sell you for that model is still the older wet style.
Last edited by MP4.2+6.0; 07-22-2017 at 08:30 PM.
07-22-2017, 08:27 PM
#24
AudiWorld Super User
The potential problem in the charging logic is that it may be designed for safety. IOW, if the battery shows that it can't be charged above 12.2 volts, the charging system will say "OK, anything higher will only damage this old battery, so I won't do it." Now you go and sneak in a new battery, without asking permission. So the charging system still says "Hey, I'm at 12.2, I'd better stop." And the new battery may NEVER see a proper full charge.
I know, IF they hired smart programmers, and IF the forensic accountants allowed them to write longer code that required more memory...then the charging system could just as well be saying "Hey, the battery was only accepting 200mA at 12.2 volts yesterday, but today it is still accepting TEN amps. Wow, I'd better give it more juice, it found a way to come back to life!"
Well, yeah, it could. Damfino. I still think we could eliminate all the uncertainty by just taking a few hostages at Audi world HQ. Honest, once the first three or four engineers disappear, the rest will start accepting phone calls and answering them. And the legal department will pay whatever we ask, as long as we don't let the diesel engineers free again. It's a win-win situation.(VBG)
I know, IF they hired smart programmers, and IF the forensic accountants allowed them to write longer code that required more memory...then the charging system could just as well be saying "Hey, the battery was only accepting 200mA at 12.2 volts yesterday, but today it is still accepting TEN amps. Wow, I'd better give it more juice, it found a way to come back to life!"
Well, yeah, it could. Damfino. I still think we could eliminate all the uncertainty by just taking a few hostages at Audi world HQ. Honest, once the first three or four engineers disappear, the rest will start accepting phone calls and answering them. And the legal department will pay whatever we ask, as long as we don't let the diesel engineers free again. It's a win-win situation.(VBG)
07-23-2017, 11:42 AM
#25
AudiWorld Super User
For questions in most recent few replies:
Also from earlier, I actually suspect the system does eventally learn effectively there is a new battery even with no replacement coding. Not logical to me just from common sense it only "learns" in one direction as battery ages. Only contra to that that occurs to me is really a time based deterioration algorithm, which I haven't heard they use. Said another way, with a lot of D3's now well over 100K miles and 10 years--where this monitoring system first appeared--I don't think anyone who just dumped in a new battery with zero recoding ever ended up with an issue of any sort, let alone some nightmare scenario. Folks have also installed AGMs without issue, though the OE fitment or what dealer would sell you for that model is still the older wet style.
Yes, Audi A8's have had water cooled alternators since at least D3. They rarely seem to fail--either electrically or with the cooling lines/circuit.
I would not hook a charger to car when swapping battery. Just disconnect and replace. Starting with my 2006 A8 (following a prior generation 2000 C5) about all I would lose programming wise was the date--not even the time was lost. Days of reprogramming radio presets, seats, keys, etc, should be over. You do have to run windows full down, full up once to reset the one touch and overlapping pinch safety function. It needs to relearn the stop point.
Reaching back earlier, I don't recall that batteries sold at US dealers are actually Euro. They have the coding sticker on them, but as explained you can just augment code by one digit and fake it out. As also stated, probably 90% plus of all batteries out there in US channels come from one of East Penn/DEKA, Exide or Johnson Controls. There are different quality levels, plus AGM or older conventional. Audi has shifted to AGM on recent generation models in general. I think Audi US ones are commonly Johnson Controls. BMW/Minis when I last had one were Exide--as I found when I peeled their label off and found the Exide one directly underneath. I would not hook a charger to car when swapping battery. Just disconnect and replace. Starting with my 2006 A8 (following a prior generation 2000 C5) about all I would lose programming wise was the date--not even the time was lost. Days of reprogramming radio presets, seats, keys, etc, should be over. You do have to run windows full down, full up once to reset the one touch and overlapping pinch safety function. It needs to relearn the stop point.
Also from earlier, I actually suspect the system does eventally learn effectively there is a new battery even with no replacement coding. Not logical to me just from common sense it only "learns" in one direction as battery ages. Only contra to that that occurs to me is really a time based deterioration algorithm, which I haven't heard they use. Said another way, with a lot of D3's now well over 100K miles and 10 years--where this monitoring system first appeared--I don't think anyone who just dumped in a new battery with zero recoding ever ended up with an issue of any sort, let alone some nightmare scenario. Folks have also installed AGMs without issue, though the OE fitment or what dealer would sell you for that model is still the older wet style.
07-24-2017, 05:53 PM
#26
AudiWorld Super User
I just came across some information that indicates that almost all brands of US "AGM" batteries are rebranded Deka Intimidator AGM batteries made by East Penn Industries.
07-24-2017, 06:15 PM
#27
AudiWorld Member
Zig-
Short answer, yes. In theory the key can be off, since those posts are there to jump start a dead car, and some folks do jump starts with the key OFF, just in case the "donor" blows the electronics in the dead car.
Just remember OZ the All Powerful is hiding in there, and may find some way to exact petty vengeance because he wasn't informed of the change.
Short answer, yes. In theory the key can be off, since those posts are there to jump start a dead car, and some folks do jump starts with the key OFF, just in case the "donor" blows the electronics in the dead car.
Just remember OZ the All Powerful is hiding in there, and may find some way to exact petty vengeance because he wasn't informed of the change.
08-07-2020, 09:47 AM
#28
Battery Maintainer Question
I’m replacing a module near the fuel tank, so it’s recommended to disconnect the battery.
But if I use a maintainer, doesn’t that partially defeat the purpose of safety? Can’t sparks still occur? I guess a 2A battery charger won’t produce much spark compared to a shorted battery (1000+ amps), but still begs the question...
But if I use a maintainer, doesn’t that partially defeat the purpose of safety? Can’t sparks still occur? I guess a 2A battery charger won’t produce much spark compared to a shorted battery (1000+ amps), but still begs the question...
08-07-2020, 10:27 AM
#29
AudiWorld Super User
If you don't use a maintainer (and they can't always reach both of the terminals under the hood, you may need to use alligator clips to extend them) you may find the windows, moonroof, entertainment system, etc. all lose settings are can be a PITA to go around resetting.
Disconnect the battery *negative*, being careful because the blakc plastic on the block contains a "pyrotechnic fuse".
Use some newspaper, or thin cutting mats, or slice open some 2-liter plastic bottles to give yourself extra insulation in the work area. Also remove any jewelry, and consider wrapping some plastic wrap round any tools handles that might short things out.
With a 2-amp charger than far away, there should be no danger, but I usually need help getting me back off the ceiling when something I've been working on goes "zzzzap" in my hands. Especially around gasoline.(G)
Disconnect the battery *negative*, being careful because the blakc plastic on the block contains a "pyrotechnic fuse".
Use some newspaper, or thin cutting mats, or slice open some 2-liter plastic bottles to give yourself extra insulation in the work area. Also remove any jewelry, and consider wrapping some plastic wrap round any tools handles that might short things out.
With a 2-amp charger than far away, there should be no danger, but I usually need help getting me back off the ceiling when something I've been working on goes "zzzzap" in my hands. Especially around gasoline.(G)
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murphyslaw1978 (08-07-2020)
08-07-2020, 07:36 PM
#30
AudiWorld Super User
I'm just going to say that a battery maintainer could make a spark just as dangerous as leaving the battery connect.
I personally would never go near the fuel pump area for a module change without removing the battery/maintainer, risk is just too great.
The forum members really don't know what settings disappear, if none, when a battery is disconnected. Maybe you will be able to tell us?
Your call...…….
I personally would never go near the fuel pump area for a module change without removing the battery/maintainer, risk is just too great.
The forum members really don't know what settings disappear, if none, when a battery is disconnected. Maybe you will be able to tell us?
Your call...…….
The following users liked this post:
murphyslaw1978 (08-08-2020)