It’s no secret that a decent battery upgrade will yield improved performance for both the audio and racing enthusiast. More often than not, everyone rips out the stock battery and replaces it with a “bigger” battery, assuming that everything will work exactly how the manufacturer said it would. What they don’t take into consideration is temperature plays a vital role in a battery’s ability to deliver maximum performance.
Most batteries are positioned in the engine bay where it happens to have the most head compared to anywhere else in the vehicle. If you have a high performance turbocharged vehicle, under bonnet temperatures are generally far higher than normally aspirated motors. No one understands the importance of good battery performance more than an audiophile who often analyse every component of an audio system in order to extract the last drop of efficiency.
What do batteries have to do with temperatures? Batteries in high performance vehicles are normally housed in a protective heat blanket or a plastic casing to keep the battery cooler. Some manufactures even go to the extent of housing the batteries in the boot as a space saving option. In order for a battery to deliver optimal performance, it needs to be kept within it’s optimal temperature, which is typically lower than the average under-bonnet temperature. Having said that, excessive heat also influences cables and their current-carrying capabilities, which is one of the reasons why routed cables routed in the engine bay never have silicon sleeve as is the case with most audio cables.
Combating under bonnet battery temperatures? As is the case with everything, there’s always several ways of which, I’ve decided to show you three that I’ve personally tried, all of which have delivered suitable results. Personally, I would always recommend you use what is fit for purpose. If it’s a turbo charged motor, then look at using the exhaust wrap or a battery blanket. If it’s a normally aspirated car with medium to high heat build-up, use the bonnet guard. Realistically, any of these three options will work. Personally, I’ve found the exhaust heat wrap to be the best option and it still costs about half the price as the battery blanket does. The bonnet guard option is probably the cheapest and easiest to do while the battery wrap cosmetically gives you the best results.
This probably requires the most effort but the results are very much worth it. For this you’ll need a length of 10m wrap, which comes in a assortment of colours from Autostyle Motorsport. You’d also need a decent length of wire to secure the wrap to the battery. I had a blown speaker so I stripped its voice coil and used that. I started by cutting strips to cover the top of the battery, allowing enough meat on either side to tie it down securely. I did small cutaways around the battery terminals and proceeded to lay each strap over the top of the battery. I then took a length of wire and wrapped it around the sides of the battery in order to tie the overlapped pieces down. I then wrapped the rest of the battery tightly and then secured the end to the actual battery at the bottom, the same way I did with the top. The end result is a well-insulated battery.