You also might consider asking for a "reconditioned battery" at a battery store. We have a "Battery Mart" store that deals with batteries and nothing else. No light bulbs. No auto repair service, etc. They have accounts with most of the businesses that use fork lift batteries and for other industrial applications.
Some of these reconditioned batteries were simply sitting on the shelf too long and they want to get rid of them. Some were bought by do-it-yourselfers who misdiagnosed a problem, then returned the new battery. Those can no longer be sold as "new".
You have to specifically ask for a reconditioned battery. They won't offer that suggestion on their own because they'd rather sell you a full-price battery with the full warranty. My store just raised the cost last year to $30.00 plus trade-in. They buy old batteries for $7.00, so I take in five, then have to pay just a little sales tax. I've gotten huge batteries for my skid steer, deep cycle batteries, even real little specialty car batteries. The drawback is I only get a one-year warranty, but I've never had a problem with the more than a dozen I've bought this way.
Also consider buying a used battery from a salvage yard. Look for the yards that buy the late model insurance wrecks. You'll find batteries less than a year old, typically for $19.99.
One word of warning before you start. A lot of newer vehicles have tricks designed in that will cause some computers to lock up when the battery is disconnected. Unless you know this doesn't pertain to your vehicle, use a "memory saver" device to maintain the computers' memories while the battery is disconnected. Some of these use a nine-volt transistor battery, and plug into the cigarette lighter socket. This only works if your lighter works while the ignition switch is off. I use a small portable charger connected to the battery cables, but you have to be careful those clamps don't pop off, and the cables don't short together.
Saturday, March 18th, 2017 AT 1:16 PM