3.7 to 5v ?

Hi Again OT,

Here is a picture of one that I took apart to use in a similar fashion to what you describe.

John

Hello John,

I ordered the boost converter and I'm waiting for it to show up. But I have another question concerning a different device: if I have a larger capacity batt with the same voltage output as the device requires, do I necessarily need a protection board of any kind between the batt and the device ?  Thank you, Oscar.

Hi Oscar,

This is a great question.

There are two main dangers involved with Lithium Batteries. #1 is over charging them and #2 is allowing them to discharge below a certain point. These two conditions can damage the batteries permanently and in some cases cause them to overheat and catch fire. We have all seen the videos of devices exploding into fire. That is the purpose of the battery protection devices. They know when the battery charge is getting too low and they disconnect the battery from the load or they sense when the battery is fully charged and they stop more charge from going into the battery.

Now if you have a way for the your device to stop working before the battery gets too low and if you are removing the batteries to charge them on an approved charger then you probably do not need the protection circuit. I for example use lithium batteries in many of the LED flashlights that I have around the house. When the light beam from the flash light starts to get weak I remove the batteries from the flash light and put them into a special Lithium battery charge that has its own battery protection circuit and recharge them. I do not have separate protection circuits for these flashlight batteries.

We all like to use the Lithium batteries because they have what is called high density energy storage. Lots of energy in a small and light package. Unfortunately the side effect is the danger that all this energy presents if something goes wrong. Since the lithium battery is fussy about how it is charged and its intolerance of being fully discharged, battery protection circuits are important. All devices that use a lithium battery have the protection circuits built right into the battery packs.

Another way that protection circuits help the charging of lithium batteries is the situation where we want to charge two or more lithium batteries that are in series. Here the problem is called a balancing problem. If the batteries are not perfectly matched one battery may get more of the charge than the other. This is caused by a difference in the internal resistance of the batteries. This allows the charger to put a higher voltage across one battery than across another. Ultimately this damages the batteries and can cause failure of the battery pack. The protection circuit can sense the condition of each battery and treat each one as if it is the only battery that is being charged.

If you see the protection circuit as a way to protect the battery while it is being used and while it is being charged you will better be able to decide if a protection circuit is needed in your application.

John

Hi Oscar,

This is a great question.

There are two main dangers involved with Lithium Batteries. #1 is over charging them and #2 is allowing them to discharge below a certain point. These two conditions can damage the batteries permanently and in some cases cause them to overheat and catch fire. We have all seen the videos of devices exploding into fire. That is the purpose of the battery protection devices. They know when the battery charge is getting too low and they disconnect the battery from the load or they sense when the battery is fully charged and they stop more charge from going into the battery.

Now if you have a way for the your device to stop working before the battery gets too low and if you are removing the batteries to charge them on an approved charger then you probably do not need the protection circuit. I for example use lithium batteries in many of the LED flashlights that I have around the house. When the light beam from the flash light starts to get weak I remove the batteries from the flash light and put them into a special Lithium battery charge that has its own battery protection circuit and recharge them. I do not have separate protection circuits for these flashlight batteries.

We all like to use the Lithium batteries because they have what is called high density energy storage. Lots of energy in a small and light package. Unfortunately the side effect is the danger that all this energy presents if something goes wrong. Since the lithium battery is fussy about how it is charged and its intolerance of being fully discharged, battery protection circuits are important. All devices that use a lithium battery have the protection circuits built right into the battery packs.

Another way that protection circuits help the charging of lithium batteries is the situation where we want to charge two or more lithium batteries that are in series. Here the problem is called a balancing problem. If the batteries are not perfectly matched one battery may get more of the charge than the other. This is caused by a difference in the internal resistance of the batteries. This allows the charger to put a higher voltage across one battery than across another. Ultimately this damages the batteries and can cause failure of the battery pack. The protection circuit can sense the condition of each battery and treat each one as if it is the only battery that is being charged.

If you see the protection circuit as a way to protect the battery while it is being used and while it is being charged you will better be able to decide if a protection circuit is needed in your application.

John