Cordless tools offer unparalleled freedom, but their battery life can be limiting, especially for demanding tasks far from a power outlet. For automotive enthusiasts and DIYers needing to use tools like reciprocating saws on the go, leveraging a car’s 12v electrical system seems like a logical solution. However, directly connecting high-draw cordless tools to a car battery isn’t always straightforward and raises questions about power delivery and tool performance.
One common approach is using DC-DC converters to step up the 12v from a car battery to the higher voltage some cordless tools require. Many converters, however, are designed for lower amperage applications. While a converter might advertise handling 15A with spikes up to 25A, heavy-duty cordless tools, particularly saws, can demand significantly more – sometimes exceeding 70A. This discrepancy can lead to underpowered tools and frustrated users attempting tasks like clearing thick bushes where portable tool batteries quickly deplete.
Simply hooking up a cordless tool to a car battery with cables might seem like a direct workaround. Initial attempts often reveal a noticeable drop in tool performance; the saw feels sluggish, and blades don’t bite as effectively. This perceived lack of power isn’t just due to slower operation; it indicates the tool isn’t receiving the amperage it needs to operate optimally at its designed voltage.
Exploring voltage boosting within the 12v car system leads to considering resistors. While high-wattage resistors exist, like those rated for 500W used in braking systems, their suitability for continuous voltage conversion for power tools is questionable. The practicality of using resistors to consistently deliver the amperage needed for power tools, especially for extended periods of operation like 30 minutes with brief pauses, becomes a concern in terms of efficiency and heat management.
Another idea involves adding a separate 6v battery, like a golf cart battery, to supplement the car’s 12v system, aiming to achieve the desired higher voltage for the tool. This approach introduces complexities around charging the additional battery from the car’s electrical system and potential overcharging issues. Rectifiers and careful voltage regulation would be necessary to safely integrate a supplementary battery.
Directly connecting a tool to the car battery can be made more effective by using heavier gauge wires. Upgrading to thicker wires minimizes voltage drop and allows for better current flow, resulting in improved tool performance. However, even with heavier gauge wires, performance can still diminish, especially in hot weather. Overheating within the tool itself can become a limiting factor. Inspection of the tool’s internal wiring often reveals surprisingly thin wires, which become bottlenecks. Upgrading the internal wiring of the tool to handle higher amperage could potentially unlock more robust performance when running directly from a 12v car battery, though space constraints within the tool housing, particularly around components like variable speed switches, need to be carefully considered.
Ultimately, powering high-demand cordless tools directly from a 12v car system is feasible with careful attention to wiring and potential internal tool limitations. While voltage boosting solutions present challenges, focusing on efficient current delivery through heavy-gauge wiring and addressing internal tool wiring bottlenecks can significantly improve the usability of 12v Tools Car setups for automotive DIY tasks.
