Q: There is a 3 year old battery in my husband’s Volvo S40. After the dealer did an oil change, they mentioned the battery could use a recharge (two hours and $15). Did they just want to add another $15 to our bill? Can you clarify and give us your opinion?
A: We see many batteries that, when tested, “charge” and “retest”. The alternator (generator) does a pretty good job of keeping the batteries serviced, but in some cases it’s not quite enough.
Could this have been a way to add $15 to the bill? Maybe, but with COVID more people working from home and driving their cars less, battery voltage can drop below normal.
A fully charged 12 volt battery has approximately 12.5 volts; the one with a 50% state of charge has 12.2 volts; and the one with 10.5 volts is in the zero state of charge. A fully charged battery is essential for the proper functioning of any newer vehicle.
Q: I need a bed liner for my new truck. What is the best ? Who do you think will be there to honor his warranty? Any thoughts on the Ameraguard liner? Also, I’m sure they will ask about adding an extra underlay.
A: The most popular spray liners I know of are Rhino Liner and Line-X. I hadn’t heard of Ameraguard, but after looking at their website, it also seems like a good product.
Like all of these spray products, preparation is what makes the product last and proper training is required.
Regarding the undercoat, the product that impresses me the most is Waxoyl. Waxoyl has been used in Europe and on high end restorations for 50 years.
Q: Lately there seems to be only one windshield repair company if you need a windshield repair or replacement.
Does the repair or replacement take a long time? Is it as strong, safe and tinted as the original glass?
A: In most cases, an aftermarket replacement windshield will be as good as the factory glass. Sometimes there may be slight differences in the tint band at the top of the windshield.
The other problem that can arise is with the optics of the windshield. I have seen instances where a replacement windshield has a negative effect on cameras and automatic wiper systems. In this case, the installer should use factory glass rather than an aftermarket replacement.
Q: I bought a vehicle for my daughter-in-law a few years ago. The engine died on it last December. There was a recall on an engine part. However, we were never notified of the recall. Can we do something?

A: If there was an NHTSA recall, it doesn’t matter if you received the recall notice. I would contact the manufacturer’s customer service number and ask how they are going to handle the problem.
Readers: You can easily check for recalls on your vehicle at nhtsa.gov/recalls. Once on the website, enter your 17-digit vehicle identification number to see if there are any open recalls on your vehicle.
Q: I want to take a long trip abroad and leave both SUVs at home in a garage. I’ve read about trickle chargers, but it seems dangerous to leave a plugged-in battery charger unattended in the garage. What do you recommend? Or do we just call AAA when we get home to charge both cars? I am looking for the best and safest option.
A: You wouldn’t use just any battery charger, you would use a float style battery maintainer. The one I know best is the Battery Tender.
These battery chargers are designed to be attached to the battery for long periods of time. They will charge the battery (very slowly) and then maintain it. I’ve seen garages full of classic cars, and each one has a Battery Tender attached without worry.
John Paul is the AAA Northeast Automotive Physician. He has over 40 years of experience in the automotive industry and is an ASE Certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email jpaul@aaanortheast.com and put “Car Doctor” in the subject field. Follow him on Twitter @johnfpaul or on Facebook.