Ray Magliozzi
Dear Car Talk:
You’ve had several columns about a guy who doesn’t drive often and wants to keep his battery from dying between starts. You recommended a trickle charger to keep the battery topped up.
Another reader wrote in to recommend a “quick disconnect,” which is a switch under the hood that disconnects the battery. You said that — as long as you avoid a cheap one — the quick disconnect is a viable option.
Here’s my question: When you disconnect the battery with one of these quick switches, does this still make your radio lose its preset stations and the engine have to relearn its programming? — Mike
Yes. That’s why our first choice is a trickle charger — sometimes called a battery tender. It plugs into a wall socket, attaches, via clamps, to the battery terminals, and automatically keeps the battery at full charge between starts, without overcharging it.
Since the battery remains connected, you won’t lose your radio and seat presets. Nor your saved engine parameters. None of those things is a huge deal to lose. The engine quickly re-establishes the parameters, and you can choose your presets again. But it is an inconvenience.
We have a device at the garage that saves those presets. We use it when we install a new battery, so the customer doesn’t whine to us about their lost presets. It’s a little piece of equipment called a computer memory keeper. It’s powered by a 9-volt battery. It plugs into the car’s power port/cigarette lighter, and it sends enough power back through that circuit to maintain the saved settings.
You can probably find one at your local auto parts store or online, and I’d be surprised if it costs you more than $10. But if you’re leaving a car idle for months or a whole season, then you have to worry about the 9-volt battery dying. So, personally, I think it’s just easier to use a trickle charger, Mike.
Got a question about cars? Write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.
