Hi guys, welcome to this new tutorial. Today I will show you the easiest way to discharge a Ebike Battery for the winter by using…

Supplies

Ebike battery (in my case a Fiido D4s one)

Lamp holder

Lamp bulb

Some wires

Why You Should Drain Your Battery in Winter

If you're reading this article is because you already know it but however...

As you might know, Lipo battery as well as LiIon are great, they provide a lot of power, they can have big capacities and they're also small for how much energy they contain (think about she smartphone's one) but...

When you are not going to use it it's better to store them in a normal temperature room (not too cold like a garage and not too hot like near a radiator).

Then, to let the battery provide all of its ampere-hours for as long as possible, you have to keep it with the battery at 50%.

Strip the Cable

To connect to the battery plate, we need to strip a cable of approximately two centimeters.

Then once the cable is stripped, you have to bend it into a hook in order to make it thicker and have more grip then on the plate of the battery.

Insert the Two Hooked Wires Into the Battery Plate

Once you have bent the two hook wires and made them thicker, you have to gently push them into the battery contacts + and - (polarity makes no difference)

Connect the Battery Wires to a Table Lamp (or Lamp Holder)

Once this is done, you have to connect the battery wires to a table lamp (or a lamp holder) and then screw in a light bulb (the old ones, not LEDs) that consumes a lot (those of the main voltage).

(if you have a way to ensure a more stable connection than mine is better??)

You now have a perfect energy load for the battery which will slowly drain it until it reach the 50% of the battery. But now the wuestion is: How can i know when the battery is at 50% ?

Find Out When the Battery Is at 50%

Of course, you will need to use a multimeter. In my case, I have a battery of a 36V Fiido D4s but don't be fooled!

In fact, my battery is 36V but this is the nominal voltage so the voltage that occurs when the battery is at 50%. In fact, my battery when it is at 100% has a voltage of 42V.

To understand at what voltage your battery is at 50% therefore, you need to know your battery and you need to know if the voltage that is written on the label is the nominal one or the maximum one (at which it charges).

To find out, just look at the charger they gave you in the package. In fact, if the charger is 42V and the battery also says 42V, then the label refers to the maximum battery voltage. If, on the other hand, 42V is written on the charger and 36V is written on the battery, then it means that 36V of the battery is the nominal voltage (because it is lower than the charge voltage) and therefore it is the voltage when it is at 50% .

Again ... if on the charger it says for example, 63V, then the maximum voltage of the battery will be 63V but if you don't know the voltage at 50%, you have to do: (63V / 4.2V) * 3.6. And you will have found that the voltage at 50% is 54V

You're Done

Now you can store your battery better for the winter