Vokell

Good morning,
I have used a battery tender over the years with my vehicles. After purchasing my 2004 TT 3.2 (and we are really enjoying the car), I was thinking I could put the tender on the TT. Does anyone else do this with their TT's? After hearing about "safe" mode for radio, and resets for everything, I don't want the battery to "go bad".

Hope this makes sense, thanks in advance for the advice.

Vegas-roadster

Sure but unless you rarely use the car it is unnecessary. When car batteries fail, it can be due to low capacity, a shorted cell or a complete short. Usually it is one of the first two which means there is still enough voltage on the system and your radio, etc will not be effected even though the car won't turn over. If it is a dead short, your tender will not be able to maintain voltage over the short so you lose your settings anyway. Make sure to hook your tender up to the TT while replacing the battery. Also, some modern tenders will not provide any voltage to an open circuit. That is, they provide no voltage unless connected across a battery which won't help you if your are swapping batteries because part of the time there will not be a battery in the circuit. So put a DC voltmeter across the tender terminals before you hook it up to see if it is providing voltage in an open circuit.

Vokell

Thank you! I wasn't sure, I take the car out once or twice a week, so not driving it much. I will look after it and not worry about "tendering" for now.

Have a good weekend!

JoeKan

Over the winter, my TT sits for about six weeks at a time. I then fire it up, let the fluids circulate and warm up the engine. Then I drive it in the parkade a couple of loops, maybe 1/2 a mile, so the tires don't get flat spots and the tranny and axles circulate the oil and lubricate the seals. Never had a battery issue.

Resets are more of a nuisance than anything else. After I pull the battery for a cleaning, it takes me maybe a minute to recode everything. Pull your radio and get the numbers off the radio case (I keep forgetting that photos are even easier), then visit your dealer or phone/chat with Audi online and they should give you your radio code.

Vokell

Excellent, thank you!

Lou-in-NJ

I use a tender on one of my other cars, but it's not for preserving the radio, it's more about keeping the battery from going dead and shortening its life overall. And while I do drive that car on nice days during the winter, I'm not in favor of short runs, I use it on trips where the engine runs for at least 30 minutes. If you don't get the oil really hot, the water vapor in the combustion blow-by will condense and accumulate in the oil; and now you have water that is able to corrode all the iron/steel components of the engine. If you're going to "store" your car for a couple of months, I'd say do an oil change just prior to putting it in the garage, since acid build up in the oil is also a problem that corrodes the metals in the engine, and acid doesn't boil off like water, change your coolant to a waterless type (which I would recommend anyway), and put the car up on blocks if flat spots on the tires are a concern.

JoeKan

Since I got my car in January, my storage wasn't really 'storage' as I was running between the mechanic and the inspection facility and the car was sitting for long periods in-between as I'm doing this on a 'pay as you go' plan. Lou-in-NJ is 100% correct to prevent engine damage and pertaining to engine storage.

To prevent flat spotting of the tyres, pump them up to max. allowed tyre pressure on the tyre sidewall - 51psi on my sidewalls, or like Lou, get them off the ground. If any flat spotting occurs, the next run you do in the car should correct it once the tyre carcass heats up.

My anally-retentive car buddy just 'educated' me on this. If you are going to store for long periods - like the winter season, like Lou-in-NJ, change the oil, take a run to get all the fluids and brakes hot, then park it within 40miles/60kms with the car in gear and without setting the hand brake so it doesn't get a chance to seize. The battery should be pulled to put on trickle, but it's probably OK to just disconnect the negative. I store my car in a public, secure parking away from home, so it has to be movable on very short notice, hence my methods may not be 'the best practice'.

The point of the thread is the battery should be OK for several months, preferably with no residual draw. I have a diesel tractor with brush cutter attachment that I run, maybe, 4 times a year, to keep the underbrush at bay. I usually park it in September and don't crank it again until April/May. Don't even put it on a trickle charger. The battery generally lasts about 5-6 years.

morris39

My experience might be helpful. Battery Tender can mean a generic trickle charger or a brand name. I ruined 2 batteries (motorcycle and van) by over charging using the brand name item. Make sure your trickle charger can equalize cell charge and stops when it should.
Short trips, particularly in cold weather can leave the battery in a low voltage condition good enough to start the car but then produce false alarms. This has happened to my MY2015 S3 , which seems to need some electronic monitoring when shut down. Dealer said it is a known issue.

Vokell

Excellent points, thank you!