Some jump starters – including the Cobra Jump Starter 1000A – can be safely used from inside the vehicle using the 12V accessory port. This accessory port is common on most modern vehicles; it's the outlet that looks like a cigarette lighter socket. While the in-vehicle method may take a little longer, it's a great option to have on a snowy or rainy day, or when you're alone in a dark parking lot or on a busy road with lots of traffic. To jump start your car using this method, here are the most common steps:

1. Turn off all accessories in your vehicle and connect the 12V jumper cable to the jump starter

2. Turn the ignition switch to the Accessory position or push the START button (depending on your vehicle)

3. Plug the 12V jumper cable into the 12V accessory port

4. Wait for the portable jump starter to indicate that it's ready (for the 1000A, it will indicate "Output Ready" and show 5 solid charging bars); this may take up to 15 minutes

5. Start your vehicle

6. Disconnect the 12V jumper cable from the accessory port and from the jump starter

If your car still won't start after trying the in-vehicle method, you may need to try the direct-to-battery method instead.

Note that you should drive your vehicle for at least 20 minutes after the jump start so that the vehicle's battery can recharge.

No matter which method you use to start your vehicle, you should fully recharge your jump starter after each use – particularly if you've used it to start multiple vehicles – and at least once every 12 months for best battery performance. Both Cobra models feature an at-a-glance status indicator so you can easily see your battery charge level.