Saturday, July 19, 2008
When an exhaust, coilovers, front lip, JDM interior trim or even power provided via ITBs or boost become standard fare, where do we go next? When all's been done and there's seemingly nothing more to do, might we suggest less as the new more? We speak, of course, of introducing weight reduction to your car's repertoire. Such a concept is not new since there's scarcely an aspect of vehicle performance that can't be improved upon by mass reduction. Indeed, a major reason why Hondas are such great cars is its favorable power-to-weight ratios. Removing interior bits and swapping items for lighter equivalents has become standard procedure, but only recently have we seen the compact, lightweight battery go mainstream.
The Basics
The car battery: A necessary evil for enthusiasts of all walks. Every car needs one and, given their size, they're inevitably heavy. Lead is the main ingredient here, which the periodic table tells us is rather heavy. Smaller batteries contain less lead and are therefore lighter but are less capable of discharging electricity. So it becomes important, before choosing a lightweight battery as a means of performance gains, to better understand them and their implications. Are you interested in the pros and cons of lightweight batteries and your Honda? Read on.
The Password:JDM battery relocator mounts an Odyssey PC680MJ low in the engine compartment providing much needed underhood space for this EF chassis Civic.
Batteries are simply energy-storing power units called upon for operating electrical devices. They're made with lead plates that directly contact an electrolytic sulfuric acid solution. Lead-acid batteries use a liquid solution while dry cell, gel cell or absorbed glass mat (AGM) batteries use a liquid suspended within a solid medium. When a battery is connected to a circuit, electrons transfer between the plates, flowing electricity through the circuit to perform work.
Electricity flows based on two properties: voltage and current. Resistance is a property of the circuit, which impedes electrical flow and drops voltage. Voltage, resistance and current can all be mathematically related to one other. If high school physics left any impression you may be familiar with Ohm's law, where current (I) is equal to the amount of voltage (V) divided by the resistance (R) or I=V/R. The relationship makes sense. Relate volts to your engine's torque output and current to the car's speed. If resistance is high (a strong headwind or traveling uphill) a given amount of torque will result in a lower speed. This relationship is the basis for nearly all things electrical.
Resistance And Extreme Temperatures
The starter is the car's main electrical device in terms of power draw. The amount of power the starter requires to initially turn the engine over is related to the engine's size, compression ratio, number of accessories being driven, internal weights and friction. Each factor emits a greater mechanical resistance and that translates into electrical resistance within the starter system. To overcome it, a battery of adequate power potential must be selected. Likewise, in a car that has been modified in such a way that resistance has been reduced a smaller battery can be used.
Braille Auto offers a battery mount specifically for its batteries. Clean, solid mounting is a must when relocating to the rear. Sealed units do not need battery boxes.
It's also significant to understand that the chemical reaction that's taking place inside the battery is temperature sensitive. The energy discharge within creates heat. When subjected to cold temperatures, the battery becomes cold-soaked, inhibiting electron flow inside the electrolytic solution. It also promotes a sulfate barrier forming on the lead plates, which translates to higher internal resistance within the battery. Choosing a battery with low internal resistance is advantageous but a good rule of thumb is to use a battery warmer when you know it's going to get cold. This not only works for OEM batteries but lightweight ones too.
Conversely, high temperatures can cause the reverse to occur. When exposed to heat, batteries experience a lower internal resistance than normal. This might sound like a good thing but the result is a self-overcharging battery. A certain amount of internal resistance is needed in order to keep the chemical reaction in check. Otherwise, the lead plates will corrode and cause the battery to swell or expand. It can literally charge itself to death.
