Using cordless tools offers great convenience, especially when you’re working away from a power outlet. However, the batteries can often run out quickly, cutting your work short. If you’re like many DIYers, you might have considered using your car battery as a power source, particularly for demanding tools like a cordless reciprocating saw. Let’s explore how to power your Tool For Car Com directly from your vehicle and what challenges you might encounter.
Initially, I looked into DC-DC converters to step up the 12V from my car to 18V, which is the typical voltage for many cordless tools. Most readily available converters, however, are limited in amperage, often around 15A with spikes up to 25A. This might seem sufficient, but high-draw cordless tools, especially saws, can demand much more – I’ve seen figures suggesting up to 70A. For tasks like clearing thick bushes where portability is key and AC power is unavailable, the standard portable batteries on these tools just don’t last long enough, sometimes only 3-5 minutes even when new.
My first thought was to simply connect the saw directly to the 12V car battery. While it worked to some extent, the performance wasn’t optimal. The saw felt less powerful, and the blades didn’t bite into the material as effectively as they should. It wasn’t just about the speed being slower; there was a noticeable lack of torque.
I briefly considered using resistors to drop the voltage and add an extra 6V. However, my limited understanding of resistor amperage and the size of appropriate resistors for this task (some 500W resistors for braking systems are huge and costly) made this approach seem impractical and potentially inappropriate.
My goal was to run the saw for approximately 2 minutes at a time, with short pauses, for a total of about 30 minutes of work. Another idea crossed my mind: adding a 6V battery, like those used in golf carts, and integrating it with the car’s 12V system. This raised questions about charging – would the car overcharge the 6V battery? And what kind of rectifiers would be needed for such a setup? This path seemed complex and potentially risky for a quick solution.
Then, I decided to test running the saw directly from the car battery again, but this time, I upgraded the wiring. Initially, I was using thinner gauge wires, which proved inadequate. Switching to heavier gauge wires made a significant difference. The saw’s performance became acceptable, much closer to what I expected.
However, I noticed the power would still diminish over time. Initially, I attributed this to the hot 105°F weather, thinking heat might be affecting performance. But then I felt warm spots on the tool itself. Upon opening the tool, I discovered surprisingly thin internal wiring. Space is limited inside, especially around the variable speed switch, but I’m now planning to reinforce the internal wiring with thicker gauge wires. My hypothesis is that beefing up the internal wiring will lead to much more consistent and solid performance even at 12V.
This experience highlights that while DC-DC converters might seem like a straightforward solution for powering your tool for car com from a car, they may not always provide the necessary amperage for high-demand tools. Direct connection to the car battery is feasible, but ensuring adequate wiring, both externally and potentially internally within the tool itself, is crucial for optimal performance. Further investigation into internal wiring upgrades seems like the most promising next step to achieve reliable cordless tool operation directly from a car’s 12V power source.
