The Stanley J5C09 is the best portable jump-starter and the most useful option in most situations. It has strong jump-starting capability as well as many useful emergency features to help you when you need it the most.
With its 1,000 peak amps and a 500 CCA rating, which is comparable to the GOOLOO and NOCO Genius jump-starters, the Stanley J5C09 can jump-start most cars and trucks – all you need to do is hook it up to the dead battery, wait a few minutes and then try to start your car. Even in cold weather, it shouldn't have trouble turning the engine over.
Unlike most other jump-starters we researched, you can use the J5C09 as a trickle charger to maintain car batteries. Batteries in vehicles you don't use often, such as the one in your RV, can slowly degrade over time, and a trickle charger can keep them topped off and in prime condition.
Few things are more frustrating when trying to start a dead battery than short jumper cables. The J5C09’s cables are 3.5 feet long, which gives you plenty of work room but isn’t so long that they’re a pain to store. In addition, the Stanley J5C09 has built-in cable storage, so it’s portable and convenient.
After you use the J5C09 to jump-start your vehicle, you recharge it by plugging it into an outlet in your home. It has overcharge protection, so you can leave it plugged in for as long as you want – it stops drawing electricity when it's fully charged. Some jump-starters don't have overcharge protection and can be a serious safety hazard if left plugged in too long.
The J5C09 has a reverse polarity warning, which is a handy safety feature. When you jump-start your vehicle, you need to pay attention to which terminal you attach the red clamp to. If you try to jump-start your car with the red clamp attached to the wrong one, it will spark and possibly damage both your vehicle's battery and the jump-starter itself.
Your car’s battery isn’t the only reason you can be stranded on the side of the road, so it's nice when your jump-starter has emergency tools and features to help you weather other adversities. The Stanley J5C09 has a DC power outlet and USB port that can keep your smartphone or other electronic devices going until help arrives. It also has a built-in LED flashlight, which is essential if you're stranded in the dark. When your car's battery dies, there isn't any electricity to power internal lights, so it can be difficult to see where and how to attach jumper cables without a flashlight.
The Stanley J5C09 has a one-year warranty, which is a decent length. However, some car battery chargers have warranties that last up to five years, which is preferable.