Good, then you will be safe.I will be busy in gardening. Hehe
A Lithium rechargeable battery protection circuit disconnects the load if the voltage of a cell drops to about 3.2V. If the voltage drops lower then the cell will probably catch on fire the next time it is charged. A battery charger IC senses that a cell has a voltage lower than normal and begins charging it with a low current to avoid a fire. If it does not begin charging or if it develops a short circuit then the charging is terminated with a warning indication.Will battery explode with charging voltage up to 4.2V, then can't use this (above) circuit and monitor its charging voltage mannually and disconnect after it reaches 4.2V?
It is Korean and looks identical to the FAKE one. It might protect but I do not think it is a battery charger circuit.But almost every Li-ion cell has its own built-in tiny chipset look like this (uploaded below, sorry for bad pic. It was a round shape Li-ion cell by LG). Is it a Li-ion charger chip you were talking about? Then can I apply any supply of 5V in the chip then will it limit everything needed for its Li-ion cell?
Two laptop batteries I opened had one battery system protection and balancing circuit.-But I think each cells inside laptop battery pack has no its own differents chip. I guessed all cells have single chipset, called battery system circuit.
Let me to explode few cells, may be after then I will begin it. But don't worry I will use a 100 meter wire and will keep the cell 100 meter far from me, like NASA explodes its each space shuttle for International Space StationWhen will you begin gardening?
Oh Yes, did you repaired then?Two laptop batteries I opened had one battery system protection and balancing circuit.
Yes you could use that chip in that circuit you posted, but it would have to be connected differently. There is another cheap very low cost charger that you could build using an LM317. Just a couple parts and you have a decent charger. If you are interested i'll post a circuit.
55 years ago my friends and I made rockets that all blew up and we made very powerful bombs that flew very high. Some of our bombs blew up by themselves. We all survived somehow with no injuries.Let me to explode few cells, may be after then I will begin it. But don't worry I will use a 100 meter wire and will keep the cell 100 meter far from me
I disconnected the cells from the protection circuit and used the best ones in an RC model airplane. They performed poorly and were very heavy.Oh Yes, did you repaired then?
Hi,Hi,
You posted right after me, so i hope you did not miss post #22.
Then I knew you tried almost everyting But I knew that each and every humans are dangerous in his youth. Oh God how danger the experiment was....... You lost your friend. Yesterday I explode a 1watt resistor on a SMPS, my heart beat was 150beats per second. Then I used goggles and helmet of my motor bike for further reparing process.55 years ago my friends and I made rockets that all blew up and we made very powerful bombs that flew very high. Some of our bombs blew up by themselves. We all survived somehow with no injuries.
But one friend died from absorbing a fuel ingredient (I think it was nitro-benzene) in the skin on his hands.
OH GOD!!! I never heared about Li-Po battery and about its power!!!!!!! How tiny and how POWERFULL!!!! Why cell phones and laptop and cars are not using these Li-Po?Here is an American modern small lightweight Li-Po battery for an RC model airplane that comes without a protection circuit. Look at its continuous output of 189A! It can provide 378A for a few moments. It can be fully charged in 5 minutes.
Wow it's so simple and tricky! But how to choose current output? like you said 1A, 2A or 2A but I need amlost 400mA. Generally for 1500mAh cell, 1A output is too much high isn't it? May be I have to apply 1 or two ohms current limiter resistor R4 to get 0.3 or 0.4A current, isn't it?Hi,
Ok well you did not reply so i was not sure if you wanted a circuit or not.
Here's a circuit that is pretty simple, but i have another one too that is even simpler. Note the IC can be a LM317 with a max current requirement of 1 amp.
Note you need at least 7vdc at the point shown in the diagram for this to work.
You should also make sure that the power can not be disconnected or the cell will be discharged over time which is not good.
Wow it's so simple and tricky! But how to choose current output? like you said 1A, 2A or 2A but I need amlost 400mA. Generally for 1500mAh cell, 1A output is too much high isn't it? May be I have to apply 1 or two ohms current limiter resistor R4 to get 0.3 or 0.4A current, isn't it?
And another- may I can use 7V to 30V as an input in LM317 (?)
Hi,The current limit resistor value is chosen to give a voltage drop of about 0.6v at the required current. So for a 1 amp current limit you would try 0.6 ohms first. The formula is simply R=0.6/Imax.
The current limit to choose could be estimated by the cells ampere hour rating divided by 2. So a 1 ampere hour cell would have a max current of 500ma. That's if you cant find the data sheet. So a 1500mAh rated cell should be charged at 750ma max as a rough guide.
I like to have about 2 to 2.5 volts of overhead across the LM317 but if you want to try lower you can try that too. As long as the cell gets the required current, and the regulator limits the voltage to 4.15 volts as a set point, and the LM317 does not get too hot with the heat sink you are using.
No.- Will it stop the charging process if battery charged fully? No chance to over charge? (I think yes)
The Battery university says that if a cell is discharged to a voltage too low and is charged then it becomes unstable. Nobody and nothing flammable should be near unstable Lithium.- What is the chance of explode battery during charging, if battery is internally shorted? Will the circuit protect or will the circuit stop the current instantly?
The current is low so ANY little NPN silicon transistor will work.- May be I can apply general purposes any NPN like BC547B there, isn't it? (but also I have 5 pieces of 2N4401 sent by Charles)
Hi,
Few basic question again-
- Will it stop the charging process if battery charged fully? No chance to over charge? (I think yes)
- What is the chance of explode battery during charging, if battery is internally shorted? Will the circuit protect or will the circuit stop the current instantly?
- May be I can apply general purposes any NPN like BC547B there, isn't it? (but also I have 5 pieces of 2N4401 sent by Charles)
Thaks!
Some batteries may have a built in discharge protection circuit.As I said before various cell has its own internal tiny chipset.
I think it is good and normal to apply this 4.2V supply for cell through that built-in internal chipset for max protection. Or will that chipset need overhead voltage too like 5V?
Didn't you see the thread here with a photo of FAKE protection chips that are sold by a Chinese company? The FAKE circuit looks identical to the real one.As I said before various cell has its own internal tiny chipset.
I don't know because my cells had a system protection circuit. I used the cells with no protection. I made my own pretty big charger circuit from an LM317.I think it is good and normal to apply this 4.2V supply for cell through that built-in internal chipset for max protection. Or will that chipset need overhead voltage too like 5V?
Few of you I meet here, I can believe fully!I made my own pretty big charger circuit from an LM317.
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