Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Since i used li polymer battery in the project,
I want to involve the charging function in circuit,
can i just soldering the DC jack and connect with the battery directly?
Also, I find that some say adding EUP8054 is necessary, is it right?
There are hundreds of different battery chargers available from many different manufacturers. It is difficult to say what is the best one for you because we do not know your application:
- Exactly what kind of battery you have?
- What is the circuit you are powering?
- What is the charging method USB/Wall adapter/colar cell/other)?
- What kind of package you can use?
A Lithium rechargeable cell is 4.20V when it is fully charged and the charging current has dropped to a low value. Then the charger should turn off.
At first the charging current must be limited to the spec's of the battery.
A Lithium battery must never be over-charged so first it must detect if the battery is already charged and if it is already charged the charger should shut off.
The charger must detect if a cell is shorted.
Many chargers detect the temperature of a charging lithium battery and turn off if the temperature is high.
The charger must detect a battery voltage too low and reduce the charging current until the voltage is normal.
The space for a Lithium battery is important because a worn out battery swells up and might catch on fire if it is charged. If it does not fit into the charging space then do not try to charge it.
There are hundreds of different battery chargers available from many different manufacturers. It is difficult to say what is the best one for you because we do not know your application:
- Exactly what kind of battery you have?
- What is the circuit you are powering?
- What is the charging method USB/Wall adapter/colar cell/other)?
- What kind of package you can use?
1. LI polymer 3.7V battery
2. the circuit included a heater and draw 1A when operating
3. Charging method through the Wall adapter Li battery charger ( output 5V, 500mA)
4. Design to use DC jack (2.5mm)
1. LI polymer 3.7V battery
2. the circuit included a heater and draw 1A when operating
3. Charging method through the Wall adapter Li battery charger ( output 5V, 500mA)
4. Design to use DC jack (2.5mm)
1. What is the capacity? Can you post a link to the specs or tell us the exact model of the battery?
3. You won't be able to operate the heater-circuit while charging. I don't see what is the point of in-circuit charger in this case. It would be easier to buy a charger and remove the battery for charging.
In his E-Cigarette thread, the battery is a Lithium 18500 1000mAh one.
An E-cigarette usually has a tiny 200mAh Li-Po battery that can fit inside the cigarette. Because of its low capacity a timer shuts off the heater after about 5 seconds. The battery must be charged or replaced every day. His much larger higher capacity battery might not need a timer and its charge might last more than one day.
He does not understand that he needs a charging circuit with protections like the one built into a cell phone. He has what he thinks is a charger but it is simply a power supply for the charger circuit that he does not have.
In his E-Cigarette thread, the battery is a Lithium 18500 1000mAh one.
An E-cigarette usually has a tiny 200mAh Li-Po battery that can fit inside the cigarette. Because of its low capacity a timer shuts off the heater after about 5 seconds. The battery must be charged or replaced every day. His much larger higher capacity battery might not need a timer and its charge might last more than one day.
Ok.. sounds doable, but if I was designing this, I would buy my Lithium battery from a reliable vendor that provides full datasheet of the battery.. wouldn't use a cheap battery and just assume max charging current, charging voltage.. or even capacity. Good thing is that the battery is probably disconnected from the load by default (when charging) and when the user wants to smoke he pushes a button that connects the battery to the load. Bad thing is that the battery is between your teeth when it explodes.
He does not understand that he needs a charging circuit with protections like the one built into a cell phone. He has what he thinks is a charger but it is simply a power supply for the charger circuit that he does not have.
Well that is why he started this thread. And I think this is kind of a good project, but you are right, he must fully understand what he is doing.. it is not particularly hard, but there is a lot of details that needs to be taken care of. Take your time, study, build a prototype, but do not connect it to a battery before thoroughly testing the circuit.
I think his battery is old and/or destroyed because its 4.20V when fully charged drops to only 3.3V when loaded with "only" 1A. Maybe it is a cheap no-name-brand Chinese battery that cannot provide much current.
A Lithium cell is dead and should be disconnected from the load when its voltage drops to 3.2V.
I showed the spec's of an American name-brand 325mAh Li-Po cell that can provide 22.75A continuously.
I have some small American 160mAh cells that provide 4A continuously and the voltage barely drops (at the beginning of a discharge).
Ok.. sounds doable, but if I was designing this, I would buy my Lithium battery from a reliable vendor that provides full datasheet of the battery.. wouldn't use a cheap battery and just assume max charging current, charging voltage.. or even capacity. Good thing is that the battery is probably disconnected from the load by default (when charging) and when the user wants to smoke he pushes a button that connects the battery to the load. Bad thing is that the battery is between your teeth when it explodes.
Well that is why he started this thread. And I think this is kind of a good project, but you are right, he must fully understand what he is doing.. it is not particularly hard, but there is a lot of details that needs to be taken care of. Take your time, study, build a prototype, but do not connect it to a battery before thoroughly testing the circuit.
1. What is the capacity? Can you post a link to the specs or tell us the exact model of the battery?
3. You won't be able to operate the heater-circuit while charging. I don't see what is the point of in-circuit charger in this case. It would be easier to buy a charger and remove the battery for charging.
I think his battery is old and/or destroyed because its 4.20V when fully charged drops to only 3.3V when loaded with "only" 1A. Maybe it is a cheap no-name-brand Chinese battery that cannot provide much current.
A Lithium cell is dead and should be disconnected from the load when its voltage drops to 3.2V.
I showed the spec's of an American name-brand 325mAh Li-Po cell that can provide 22.75A continuously.
I have some small American 160mAh cells that provide 4A continuously and the voltage barely drops (at the beginning of a discharge).
Does the heater heat enough when the battery supplies it with only 3.3V or 3.55V when the charge is new?
When the battery voltage drops from 4.2V when fully charged to only 3.3V when it is almost dead then does the heater heat enough?
A charger circuit for a Li-Po battery cell usually has an IC. You cannot use a "charger " for a cell phone because it is not a charger, it is a 5V power supply. The charger circuit is inside the phone.
Does the heater heat enough when the battery supplies it with only 3.3V or 3.55V when the charge is new?
When the battery voltage drops from 4.2V when fully charged to only 3.3V when it is almost dead then does the heater heat enough?
A charger circuit for a Li-Po battery cell usually has an IC. You cannot use a "charger " for a cell phone because it is not a charger, it is a 5V power supply. The charger circuit is inside the phone.
I think the 1A limit of your battery reduces the voltage to 3.55V when the battery is fully charged. Then the heater is 3.55V/1A= 3.55 ohms.
As the battery voltage drops when it is used then I think the maximum current and voltage across the heater will also drop.
You need a more powerful battery or a battery cell.
Here is test review for a Sanyo 18500 Li-Po cell. It is rated at 3A, is protected (max current is 8.3A) and has a capacity of 1500mAh.
Its voltage starts at 4.05V when its current is 1.14A and drops to 3.55V in 80 minutes. https://www.candlepowerforums.com/v...est-Review-of-Keeppower-18500-1500mAh-(Black)
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
