Can lithium battery be used as start battery?

Can lithium battery be used to boot a vehicle’s engine, just like a lead-acid start battery?

We have received so many questions from buyers about can he install the ECO-WORTHY lithium battery in the car to start the engine?

Our answer is No, our ECO-WORTHY lithium battery can’t be used as a car engine start battery.  Because car batteries do an unusual job than lithium batteries.

Why the lithium battery cannot be a start battery?

The problem is not the battery themselves, is about how that car engine and alternator work. so let’s talk further about that.

A. When you turn the key to start your car, the start battery need to release a very very large current, which can be hundreds of amps to start the engine, even though this process only lasts for a second or two, it could blow the BMS board in your lithium batteries.

B. When the engine gets started, it will turn the rotor in the alternator, but the alternator has no magnate, and can’t charge on its own. You have to have 12 volts applied from the battery to the field coil on the alternator to get it to start. The alternator generates a current which is sent to the voltage regulator. And the voltage regulator converts it from AC/ to D/C and sends it back to charge batteries and power devices on the car.
The problem again is that lithium battery built-in BMS will monitor all the operation parameters of battery cells. Once there is parameter is out of specification for what it is programmed, it will completely shut down the batteries. 

C. Additionally, the alternator and regulating circuit in cars are designed to charge lead-acid batteries, not lithium. Typically, your alternator is going to be around 14.7V, it could reach as high as 15V. So there is a risk of the BMS shutting the batteries down from over-voltage.
So what happens next if your battery shuts down while the engine is running. The problem is as soon as the battery shuts off or as soon as you remove one of the cables from the battery, you are going to see an instantaneous spike in your electrical system from the alternator before it catches up with the fact there’s no battery installed, even if it only lasts for a few milliseconds can be detrimental to your computer system your sensors any electrical circuit in your car. The most risk for damage from voltage spikes is going to be your ECU, that’s a tiny computer under your dashboard or back in that area that gathers data from all those sensors and pretty much manages the entire computer of your vehicle. That ECU can be anywhere from a couple hundred to couple thousand dollars to replace depending on your car.

D. Compared with lithium batteries, Lead-acid batteries have extremely low internal resistance, so they can deliver very high currents. But lithium batteries have an internal resistance that may be 10 times higher, so a lithium battery of the same voltage as a lead-acid battery can only deliver maybe 1/10th of the peak current.

E. The car battery’s working environment is also an issue. The engine under the hood of the car will generate heat, and for most cars battery bay is next to the engine, that’s not a proper environment to place a LiFePO4 battery.
If you live in somewhere have cold weather in the winter, you will have trouble starting your car when it’s below freezing. When you start the car engine, the alternator is going to begin charging batteries, but the batteries can’t be charged below freezing or you will permanently damage the LiFePO4 batteries.

What should I do if I want to replace the old lead-acid start battery?

Today, some car manufacturers developed a computer-controlled charging system in cars, called an intelligent battery sensor which monitors the battery’s voltage and other important charging voltage-related information to make sure the system is operating correctly.

And there are a few lithium batteries on the market that are designed for the car.

Even though still not all the batteries can operate correctly with that, there still are several limitations on the battery parameters and manufacturing materials and you need a professional worker to do the exchange and settings adjust for your car.