[JFP in PA]

For years, we provided winter storage for special customer's cars, which included battery maintainers (not cheap trickle chargers, but a high quality Ctek electronically controlled true maintainer systems, which are both internally and externally fused), as well as for my personal "fleet" in an environmentally controlled and highly secured facility. In all the years we did this, we never had any problems with any of the cars, many of which were with us typically from mid-October until late March.

The "secret" is the battery maintainer, which brings the battery up to full charge, then shuts down until it detects the battery dropping off, when it comes back on to top off the charge again before shutting down again. One of the things that show how effective these systems are is in the fact that we top off every flooded battery with distilled water before the car goes into extended storage, and nearly six months later, it still does not need any water. I have personally stored cars for over a year without starting them, and they all came to life instantly when it was time for them to come out of storage. Use quality maintainers, and you will not have any issues. I have also run AGM batteries this way, and often gotten 10-12 years out of them before they started to show drop off during annual load testing, indicating that while they still worked, it was time to replace them.

The problem with disconnecting or removing the battery is not what it does to the battery, but what it does to the vehicle, which can be both difficult and expensive. The car simply does not like it.