battery eating - why do we put up with it
 

Again for the second time in 9 months I've started to see my low battery warning.

Below are just a few but there are many search hits on the internet. I have come across some accounts of people saying to lock the car at night to put car in sleep mode and others to keep the key fob over 25 feet away.

Sometimes I have to scratch my head asking what an engineer was thinking and not just about cars. I recently replaced the motherboard in my one laptop. The CMOS battery, which is usually a drop in event was soldered to the board. I can do soldering jobs on the boards but what about people who have no experience and would burn straight through that board.

https://www.swedespeed.com/threads/b....234943/page-2
https://www.theglobeandmail.com/glob...article627046/
https://www.swedespeed.com/threads/b...roblem.183619/
https://classactionsreporter.com/vol...ction-lawsuit/

"Today they told me that the issue is a faulty R DAR module, whose normal job it is to turn off the satellite receiver when the car and the radio are off. But when the module malfunctions, (like basically everyone's will at some point), the car will keep pinging for connection to the satellite using the car battery even when everything is off. So the battery drains. It does not matter if you've never turned on the radio, or ever connected to the SIRIUSXM service, they said."

"One is the Volvo 2.0 update and the other is the RDAR update. The RDAR update should have addressed the Sirius parasitic draw. Both are covered under warranty and out of warranty. This issue has long been known by Volvo dealers. Yet, if you read the accounts throughout this forum about multiple dead batteries, low battery charge warning, and Sirius parasitic draw, you’ll find repeat occurrences where dealers never seem to have gotten the service memo. Search Swedespeed and you’ll find the actual service bulletins posted. You may need to go back to the dealer with them in hand and question the charges."

https://www.swedespeed.com/threads/s...epairs.602727/
https://volvoforums.com/forum/volvo-...ep-step-94470/

Add a little bit more information.

Last January the dealer did do an update to the Sirius radio which is supposed to fix the issue. The problem is that if the issue had been in existence for a while, the constant drain and re-charge probably killed the battery or at least led to a premature death.

On the January 2020 shop report the tech reported battery voltage of "12.06 volts - good battery". Hm? I keep looking and looking and looking and everything I see says 12.06 volts (at inside shop temperature) is not a healthy fully charged battery. So I am thinking that the battery should have been changed last January 2020. Heck for all I know the battery wasn't all that healthy during the CPO inspection. Even though there is a spot on the report that says "Battery (condition/fluid/level/load test - record readings)" there is no recording noted on the inspection report. So who knows what the voltage was on the battery at the inspection? Most likely my Volvo dealer should have replaced the battery at the CPO inspection.

From everything I found to research the chart below is fairly spot on --

Battery Voltage and State of Charge (at 80 degrees F):
(NOTE: Subtract 0.024 volts for every 10 degree F drop in temperature)

12.66v . . . . . . . . . . 100%
12.45v . . . . . . . . . . 75%
12.24v . . . . . . . . . . 50%
12.06v . . . . . . . . . . 25%
11.89v . . . . . . . . . . 0%


"Automotive lead-acid batteries should be maintained at a 75 percent charge level or higher for best performance and life. If the battery is allowed to run down and is not brought back up to 75 percent or higher charge within a few days, the battery may be permanently damaged. Sulfation can prevent the cell plates inside the battery from accepting a full charge. Over time, this will lead to diminished battery performance and life."