BMWBig6

Last week I had the car battery replaced (with a brand new OEM/VW battery). I drove the car a few times following the battery replacement without incident. But yesterday I received a warning message to the effect of "Low battery - vehicle will charge battery while driving." At first I thought maybe the car was reporting a low voltage condition that occurred during the actual battery swap, but that happened days ago and the dealer claims they kept the car hooked up to another battery during the swap to preserve any settings, radio presets, etc. which would have theoretically prevented any such low voltage condition.

So what's going on? Is this common after just replacing an old battery with a brand new one? Could the new battery just need to be "topped off" after sitting on the warehouse shelf for who knows how long? (I have no idea how much charge a new battery should hold in storage before being installed in a vehicle, but I imagine it's not 100%).

audi01a6

who did it?

audi01a6

did they ck output of alt.?

BMWBig6

Dealer, not sure if they checked alternator output (or if it's normally included in any battery replacement).

Moviela

Your battery may have been shipped dry (acid shipped separately.) To activate these batteries, start by removing the vent caps. Using approved battery grade electrolyte (1.265), fill each cell half way between the plates and the bottom of the vent well tube. It is important not to over fill the cells as the acid will expand upon charging. If the cells are too full, the acid will spill out of the top of the cells. Allow electrolyte to saturate into the plates and separators for at least 90 minutes. The temperature of the electrolyte will rise and the specific gravity will drop.* Once this is complete, place the batteries on charge at the finishing rate (5% of the 8 or 20 hour rate). The rate may be increased if the battery does not begin to gas. Do not let the cell temperature exceed 115° F (46° C). If the temperature becomes excessive or the cells begin to gas vigorously, reduce the rate of charge. Continue charging until the cell (or cells) reaches within .005 points of the specific gravity of the filling electrolyte corrected for 77° F (25° C).

I usually continue charging for an additional 60 minutes to insure no further rise in specific gravity.

Top up or remove electrolyte as necessary for proper level. Never add electrolyte (only approved water) after activation. Replace vent caps and remove any spillage of electrolyte. If necessary, clean with bicarbonate of soda and water (100 grams of soda to one liter of water). Rinse with water and wipe dry. Ensure that soda solution does not get into cells.

*Do not place on charge until electrolyte temperature is below 95 F (35° C.)

Equalization is sometimes needed on new battries.

Individual cells will vary slightly in specific gravity after a charging cycle. Equalization or a “controlled overcharge” is required to bring each battery plate to a fully charged condition. This will reduce stratification and sulfating, two circumstances that shorten battery life. Equalization of the battery recommended when the battery is not properly charged after filing. To equalize the cells, charge the batteries until the voltage elevates to the “Equalization” voltage of 15.48 to 16.02V. Charge parameters and maintain for 2 to 3 hours. A constant SG (specific gravity) for 30 minutes is a good indication of cell equalization. It is recommended to water the battery cells half way through the equalization. This will assure the water is mixed with the electrolyte.

Most shops don't do this because they want to sell you a new battery sooner. They simply fill the battery, and put it in the car. Most shops have no thermometer nor hydrometer to do proper battery service.

zulujams

How long did you drive the car Ben? If you're only making short trips, the battery may not be charging up fully? I helped a local guy with some VAGCOM settings and the car had low battery issues (new car). He took it for a longer drive and the errors went away and the battery meter we enabled showed full too after that.

Moviela provides some great detail, too. I have some mechanical and technical background but not with cars. I'd lean more toward having the dealer take a second look based on my abilities and with my car under warranty (and their work should have a limited warranty even if your car is out of warranty?).

precinder2

The content of that post was copied from the Rolls Battery website. Plenty more info there:

http://www.rollsbattery.com/content/tech-faqs

BMWBig6

OK thanks for all of the suggestions, the car is back at the dealer now. I reminded them about BEM coding for the battery and told them to confirm the battery wasn't dry and check the electrolyte levels. They did a battery test and said it failed the "load test" which seems weird to me (for a brand new battery) but perhaps improper installation due to the number of possible causes already suggested is handicapping the battery's performance. Either way, the dealer is motivated to make things right.

The new Audi battery cost $270, Part Number 000915105CEDSP (I think that's the part number because I was transcribing it over the phone). I wondered if perhaps they ordered the wrong battery but they said that's the part number that came up when they typed in my VIN (and said one part number may reference or supersede another so it's very confusing?).

Yes, I've mostly been taking short trips since installing the new battery (10 miles or less) though I did just take a 100 mile round trip yesterday. In the 6 months prior to my needing a new battery, I only drove the car 1,312 miles (~219 miles a month) so that might explain why the original battery expired early? I'm trying to drive the car more often now that it has the new battery (but sitting at the dealer is probably not helping).

zulujams

Good luck Ben, let us know what happens. Batteries have shelf lives, so maybe the dealer put in an 'old' off the shelf unit. Parts can outright fail too. I work in the computer industry where we test the crap out of our hardware before selling it to customers, and we still see some fallout of components including batteries.

If you find that your car is sitting often, you may want to look into a battery tender. I have one for my bike which is made specifically to charge up the battery and shut off at a certain level so that it doesn't "trickle charge" forever and kill the battery. The terminology can be confusing--battery charger, maintenance charger, trickle charger, battery tender...some of these are great for recharging a low battery but are not good for long term connection to the battery. I don't have a recommendation for a car battery, but maybe others here can recommend something.

perdido34

I got a battery warning light on my car. The cause was rodents feasting on the wiring. Cost $3200 to repair. Lucky you--your problem was only the battery...