Secondary Battery Installation
My car is supposed to shut the headlights off when the car turns off. On occasion, it doesnt and my battery can't start my car. A jumper pack would alleviate this and I could take care of the situation myself. However, they are $60-150 and id rather invest that money into something multifunctional.
Install a secondary battery in the trunk with an isolator/relay installed between the two batteries. The battery in my trunk would be used to keep my computer in sleep while the car is off (Intel Atom, SSD, 2 memory sticks). If my car decides to not shut off my headlights again, I would then be able to disconnect everything from the secondary battery and use jumper cables to jump my main battery. I would do it with jumper cables because the main lines I have between the batteries are not large enough to send the cranking amps without the potential of melting something/starting a fire.
Am I missing anything?
What type of battery should I use? (SLA/AGM/Deep Cycle/Starter/# Of AH)
How do I calculate the amperage drawn while my computer is sleeping? (Or would getting something to measure it be easier, needed for AH)