One thing that cars and alternative energy have in common is that they both need batteries to function properly. Many people who have to deal with dead car batteries find themselves asking what type of battery do I need for my car? I’ve had a lot of people email me asking if they can use their old car batteries for their renewable energy applications. Unfortunately, the answer to this question is “NO”. Your car will use a 12v battery but that’s where the similarities end.
Automotive batteries are primarily designed for starting your vehicle. After the engine has started, your vehicle gets all of its needed electrical power from your vehicle’s alternator. Automotive alternators are sized so that they can recharge the energy that was used to start your car as well as power your electrical accessories like lights, radio’s, windshield wipers, and heater blower motor.
When you need to replace the battery in your car, it’s not hard to find out what kind you’ll need. You can simply walk into your local automotive store and tell them the make, model, and year of your car and they will hand you a perfectly sized battery. All cars require what are called 12v “starting batteries”. Batteries uses for renewable energy applications require “deep cycle” batteries. These batteries are specially designed to be able to be deeply discharged multiple times without sustaining damage.
If you drain your car’s battery too low even a few times, your battery will sustain damage. They are really only designed for short bursts while starting your vehicle and for short intervals of using the lights or radio while your vehicle isn’t running.
When it comes to picking a battery for your car, the main thing to keep in mind is that each car will have a slightly different sized battery box and battery hold down system. It’s possible to start your vehicle with virtually any 12v automotive battery so what you really need to keep in mind when replacing an automotive battery is whether the battery will fit into your vehicles battery box and whether the battery hold down system that your vehicle is equipped with will work with the battery that you purchase.
There is another thing to consider when purchasing an automotive battery suggested by a reliable source who work in a Car Service Woolloongabba establishment, that I almost forgot to mention. Some batteries have posts that are used to connect the battery cables to. Others have tapped holes and you bolt your vehicle’s battery wire connectors to the side or top of the battery.
Many people who have power inverters installed in their vehicles destroy their car’s battery in a very short period of time because they allow the battery to drain too far before recharging it. They usually wait until the inverter’s low battery alarm goes off and then they start their car and run the engine for a few minutes and think that this is sufficient to charge the battery.
This is not only hard on the battery, it’s also hard on your car’s alternator. Alternators aren’t really designed to charge a deeply discharged battery. A deeply discharged battery places a very large amperage draw on the alternator. Do this too many times and you’ll find that you’ll not only need to replace your battery but your alternator as well.
So if you find yourself asking what kind of battery does my car need, now you know how to find the exact size your car should use and if you find yourself wondering if you can use your old car battery to power your power inverter, you know that that’s not a good idea as well.