There are many rumors circulating within the tool industry about the performance of power tool batteries in extreme hot and cold temperatures. Let me take a moment to dispel a few of these rumors with some cold, hard facts.
In actuality, your batteries will always underperform in extreme temperatures. Hot and cold environments confuse and disorganize the cells inside your battery that allow it to generate the energy and power you require from your tools. In extreme temperatures, those cells literally can not perform and consequently, your battery can not perform either. The battery can not properly deliver power to your power tools, and can’t re-begin working at full capacity until its internal equilibrium is restored.
Not only do these extreme temperatures and conditions temporarily discombobulate your battery, but overtime, they will actually permanently destroy the battery’s cells rendering the battery all but absolutely useless – at that point your once brilliant power tool battery may serve only as a paperweight or perhaps the stone-cold living memory of a once vivacious, power-housing accessory. In other words, dramatic hot and cold temperatures will cause your batteries to work improperly, and given a little extra time or wiggle room, will cause your batteries to flat-out die.
Any unexpected and extreme temperature fluctuations are very unhealthy for your batteries, they are a super-shock to the system that is painfully difficult to bounce back from. Interior energy cells will begin to deplete and die until eventually, and usually prematurely, your battery is totally and entirely exhausted. In the end, and contrary to some circulating rumors, cold temperatures do not, in any way whatsoever, conserve nor improve battery life or performance; in fact, they will annihilate your battery from the inside out. Similarly, hot temperatures will generally broil your batteries and their power cells into a sad state of drooling oblivion. Extreme conditions and hot and cold temperatures will effectively kill your power tool batteries. No ifs, ands, or buts about it.
Ultimately, your batteries want to be warm, dry, and temperate – I repeat, warm (as in room temperature), dry, and temperate – just like you. Don’t put them in the freezer, don’t leave them in the heat, don’t leave them in your trunk or truck bed, and don’t overcharge them. Simply love them and honor their needs, and they will work hard for you until their end of days. Keep them in the garage, or better yet, bring them in the house for dinner and a movie to ensure they maintain optimal temperature and an always optimal performance.