Charging is too slow?
Posted: Wed 20 Dec 2017 11:18
Hey guys,
Got a question about the charging process, and that it was too long. So I wrote a little explanation about the charging process and how to improve it :
Some 5V charger are little bit more than 5V, maybe 5.2V, because most often it helps. But here it does not help. In fact best rating for charging the raspiboy is 4.5V.
The thing is that the lithium battery is between 3.2V and 4.2V. And when charging, the battery charger needs to lower the voltage to the battery voltage. So to 4.2V. So if it is supplied with 5.2V it needs to reduce by 1V the voltage. If it is supplied with 4.5V it only needs to reduce by 0.3V
In order to do so it must dissipate the extra energy into heat, and the more voltage drop the more energy (by the formula P = U x I)
And in order to prevent overheat and give the product a better durability we implemented a overheat protection. So if temperature is going to high the charging process will pause for some time, allowing temperature to drop.
This process can be seen on the LEDs, when LED 3 ON and LED 4 OFF, it's charging. When LED3 ON and LED4 ON it means it's cooling down.
So if your 5V charger voltage is bit high then there's more heat to dissipate so cooling time is longer.
So best is to use charger with bit lower voltage than 5V.
A way to do so could be to use a USB-micro USB cable of low quality. Because in those USB cables they use thin wires to save cost. And that produce a voltage drop. Which is usually bad, that's why they are considered low quality. But in our case the voltage drop will help.
Got a question about the charging process, and that it was too long. So I wrote a little explanation about the charging process and how to improve it :
Some 5V charger are little bit more than 5V, maybe 5.2V, because most often it helps. But here it does not help. In fact best rating for charging the raspiboy is 4.5V.
The thing is that the lithium battery is between 3.2V and 4.2V. And when charging, the battery charger needs to lower the voltage to the battery voltage. So to 4.2V. So if it is supplied with 5.2V it needs to reduce by 1V the voltage. If it is supplied with 4.5V it only needs to reduce by 0.3V
In order to do so it must dissipate the extra energy into heat, and the more voltage drop the more energy (by the formula P = U x I)
And in order to prevent overheat and give the product a better durability we implemented a overheat protection. So if temperature is going to high the charging process will pause for some time, allowing temperature to drop.
This process can be seen on the LEDs, when LED 3 ON and LED 4 OFF, it's charging. When LED3 ON and LED4 ON it means it's cooling down.
So if your 5V charger voltage is bit high then there's more heat to dissipate so cooling time is longer.
So best is to use charger with bit lower voltage than 5V.
A way to do so could be to use a USB-micro USB cable of low quality. Because in those USB cables they use thin wires to save cost. And that produce a voltage drop. Which is usually bad, that's why they are considered low quality. But in our case the voltage drop will help.