My wife's 2007 Volvo S60 has been having a hard time starting lately. Her battery has gone dead a couple of times this past week even though there is no obvious reason for that to happen. I have charged the battery both times by driving the car 30 miles at 40mph and over, and putting the battery on a trickle charge. Also, when starting, there is a squealing sound coming from the engine compartment. When starting, the ignition sounds like its having a hard time catching, and the squealing occurs at the same time.
Replies and advice much appreciated.

 

Squeals are usually the sign of drive belt slippage or an accessory with bad bearings. Considering your battery is going dead, that points to a faulty alternator. If you have a volt meter (even a $20 harbor freight model will do), measure your battery voltage with the engine off. An 80% charged battery will show 12.6V, Less than that means the battery is not charged or if its like 10V, it means it has a dead cell. Now if you can start the car, test the battery voltage with the engine running. It should show 14 to 14.5V Anything less than 13 won't effectively charge the car. I'd suspect you may see the voltage wander as well, which is also a concern. To really get to the root cause of the squeal, you'd need to inspect the belt for wear, then remove to see if any of the accessories feel like they are binding up. You'd also need to feel the tension to make sure the tensioner is doing its job.

 

Thank you for that information. Don't have a volt meter, but will buy one. Good opportunity for me to learn how to use a new tool. Will check the battery per your specs.