Jeff928S4

Looking to replace the battery in the SUV.

A little background.....I seem to always be having battery/charging issues with the my car (1989 928).....must have had the battery charged from dead 10 times (turns out, this lowers the battery's ability to charge back up to full capacity). Eventually figured out my short drive to work (under 2 minute) and putting around town isn't enough to keep a battery fully charged; I need to keep it on a maintainer/give it a nice charge up once in a while or it will drop to the point of eventually weakening it. I put a Yellow Top in the car and have maintained it at full charge ever since.

Now, the SUV is the same story. Things is, when I bought it, they had just put a new battery in it...but the times I went over to look at it/drive it, they always had to jump it because the new battery was always dead (would die in a week if just sitting there). I've driven on that battery for a year and a half and have had to charge it back up repeatedly last winter. At full charge, it only shows a 12.35 - it's not topping up.

These Cayenne's are known for having wayyy too much electrical load on the battery. I read somewhere that when the President of Porsche was about to see the new Cayenne revealed, the meeting was delayed because the battery was dead in the Cayenne lol. Some much stuff seems to keep running after you shut it down.


Anywho......gonna go pick up a new battery tonight. The one I have in it now is some knock-off no-name the lot put in it. It has 850 CC, but it's been dead/revived too many times and needs replacing.

I need an H8 (group 49) with at least 850 CC - the higher the better. I could fit an H9 in the spot under the drivers seat where the battery sits, but it seems hard to find that size locally.

I have 3 main options....(the "Motomaster" battery is a "Canadian Tire"brand here in Canada.)


1. Everstart MAXXX (Walmart) - 900 ColdCrankingAmps/185 Reserve Capacity - $153.00


2. Motomaster Eliminator - 900 ColdCranking Amp/1105 CrankingAmps/185 Reserve Capacity - $190.00


3. Motomaster Eliminator AGM - 850 ColdCrankingAmps/975 Cranking Amps/170 Reserve Capacity - on sale this week - $220.00


It would seem the non-AGM batteries have more power, but is the AGM a better battery for my situation? The Walmart Battery and the non-AGM Eliminator seem to be pretty much the same, so it's a matter of choice between those two I guess.


Which battery would you buy??

Rossi

I had the same problem. Replaced my battery with Bosch unit, ended up replacing it 18 months later. I am not familiar with the units listed on your post. I purchased Interstate battery and I have absolutely no issues ever since. Interstate offers 24 month free replacements and warranty for up to five years.

INTERSTATE Mega-Tron 49/H8 900CCA approx. $180

Jeff928S4

Do you think the Bosch was a bad battery?

AGARubberDuck

The H9 is hard to find, but IS the correct size for the 955 regardless of what the the vehicle look-up database says.
I replaced my battery with the recommended H8 in 2012, then replaced again in 2013 and 2014. I continued to have electrical gremlins and would replace the battery when it seem to no longer take a charge. Last time I replaced it (earlier this year) I ordered the H9 size. it fits in the box under the seat better and I'm not having to throw the trickle charger on it every week like I used to.

I highly recommend calling a day or so before and getting the right size ordered in.

deilenberger

And before you install the battery - put it on a charger overnight so you know it's 100% charged. A battery that is put into use without being fully charged is unlikely to ever achieve full charge in use.

Rossi

Not sure, i did not want to deal with it again. Decided to get Interstate unit, the Bosch had a two year replacement warranty, my Indy gave me $ credit towards future repairs as I declined the replacement unit.

Jeff928S4

I am currently seeing if I can order in a H9...if not, I may go with the AGM, as it may be better due to the deep cycle abilities.

I will also make sure to charge it fully before putting it in the Cayenne.

Receiver

Was having battery problems with my turbo. Continually discharging. Thought it was because I wasn t driving it enough. Turned out that my ignition switch was faulty. A $15 Audi part and problem solved. Might be worth checking.

Dan87951

Do you have a part#? Might be helpful to future members who are having this problem.

Thanks

Receiver

Part# is 4A0905849B. It s for an A4,A8 and 911. There's probably something similar for Touareg, Q7 and Cayenne. I understand dealer charged someone $750 for this fix compared to my cost of under $100 including my Indie's half hour of labour to install it.

I m probably buying a 2014 CS in a couple of weeks which is why I m surfing this forum.

8202632

do u have autozone in Canada? That's where I got my h9 battery. Been great ever since I bought it. Sounds like u have electrical drain issues. I got my h7 battery at Walmart for the carrera s and it's been good too. Both batteries while privately labeled something had the audi rings and vw markings etched in the plastic. So there must only be a handful of suppliers.

Jeff928S4

Nope - no Autozone in my parts.

stubenhocker

Go for the WalMart battery, i've purchased two of them, for various BMW's, with no issues.

Jeff928S4

I think that is where I'm leaning. In pricing similar batteries, with similar specs, the Walmart battery is always $30-50 cheaper.

I have been playing around with my voltage meter and have got my battery up to a 12.70 area when "fully charged" (after leaving it on my Genuis charger for about 2 hours)....but as Im reading that number (immediately after removing the charger), it literally drops from 12.70 to 12.69 to 12.68, etc. right before my eyes (with hatch open/interior lights on). "Maybe there is a drain?????", I thought.

I started the car last night around 9:00 p.m. - went for a drive of about 15 minutes total (but stopping every 5 minutes - so three short drives). I check the meter and it says 12.45. Seems like a lot of drop for 3 car starts/doors being open for a minute or two, no?

Figuring there is a drain of some sort, I went out this morning and put the meter on it right away....still reads 12.45??? Huh?

Drive to work (3 minutes of driving), check again - still 12.45. Drove 3 minutes home from work, still 12.45.

Put it on the charger again, and this time it only took 20 minutes to charge fully - reading 12.85 now.

Maybe if I just stay on it every day, I can keep the battery voltage between 12.45-12.8ish - that seems to be a good amount for goods starts, etc.

I'll keep an eye on it as it gets colder/I try using that REST button - that should tell the real tale.

....I may also go out when it is in the 12.80 area and see how long it takes (with the doors open or the REST button on) to drain the battery down below 12.00 (that is the voltage I can still start the car, but get warning lights after start up - the battery is barely working at that number).

Garth S

Jeff,
The Walmart batt will do the job .... but also give your local VW dealer a call: they always have three sizes in stock ( all of identical width & height and equal to the Cayenne spec). The longest case is the one you want, which I recall being an H8 ---- more than enough to do the job - same battery as Porsche offers, better $$.