A: Good question. When a product fails to perform its expected function, it doesn’t always mean that it is substandard and cannot meet its specification. Here is a summary of the most common reasons why your power bank fails to jump start your car and the possible solutions to each one of them. They can be divided into the following 2 categories.
a. After the failed jump start attempt, you can still power on your power bank and the power capacity indicator still have at least 3 lights on:
There are 2 most common causes for this problem. First, the bite of the clamp may not be good enough. In order to deliver the optimum electric current to jump start your car, you need to make sure that both red and black clamps achieve the best bite on both battery terminals. At the same time, you should clamp on to the part of the terminal that will give you the maximum area of contact. Second, have a visual inspection of the surface condition of the battery terminal. If they are badly corroded or rusty, use a sand paper to sand out the rust then reattach the clamps. After you have done the above 2 procedures, try to jump start again. This time your engine should start running!
b. After the failed jump start attempt, the power bank seems to drop dead. Pressing the power button won’t turn the power bank “ON”:
This situation is quite complicated and may be caused by a lot of possibilities. We will discuss the matter in as simple and as practical as possible. We divide this into 2 general categories.
b.1. The first one is that the power bank is under powered, meaning its capacity is too low to jump start your car. Here are two most common observations. First, when you start the engine, you can hear that the flow of the current is cut short and the power bank dies out prematurely. You just hear a very brief crank, probably less than 0.5 second. When this happens, and if you can smell a strong burnt odor, your power bank just got “fried” and it is gone forever! Given the same situation, and if your power bank has “over-discharge protection”, then it won’t smell. It will shut down immediately to protect itself from being “fried” when it senses that it cannot deliver the required current. You can just revive the power bank by recharging it with its wall charger. Since it is under powered for that particular car, you may use it only for smaller cars. Click on this link to watch this video: (video title: “over-discharge protection”)
b.2. The second one is that your power bank’s capacity is just within the required capacity of your car. In this situation, you will hear that the cranking is continuous and the power bank seems to have the power to sustain the jump start but shuts down after 1-2 seconds. Under this situation, refer to FAQ #18a above, then jump start a second time. Make sure that you let the power bank rest for at least 30 seconds in between jump starts to prolong its life. With our power bank, after the first failed jump start attempt, it will automatically increase its output current in succeeding attempts. This is one of the many good features of our power banks. It is recommended that you try up to a maximum of 3 times. But if you are in an emergency situation, you can max it out up to 5. Just remember to have a 30-second rest in between jump starts. During this time, the energy level indicator of power bank may not light up when you press its power button, but it can still deliver the needed current. The energy level indicator functions independently of the 12V output port that is used for jump starting. In this case, you won’t have a guide as to the actual power level of your power bank. You may want to revive it later after you have successfully jump started your car by simply charging it with its AC wall charger. (Please visit this video link: video title: “Over-discharge protection”)