RC India

Guys i got a question. Can i charge my 4200 mah 3s lipo battery using b3 charger, The problem here is i want to only charge my 3rd cell of battery and another problem is my charger's 3rd cell slot is damamged.
Pls help me i you know it..

Thanks in advance....  :hatsoff:

Brother, you can use a normal mobile phone charger to charge the specific cell of the battery. It's 3.7v so it will be fine.

you can use TP4056 module to charge 3rd cell.

Al Ham Shari - a mobile phone " charger " as you put it - is not a charger . it is a 5 volt
power supply.

the actual charging circuit is integrated in a mobile and part of the battery management system.

if you use to charge a unprotected lipo cell - it will be destroyed.

better to use a cheap an foolproof TP4056 module as taksh suggested.

@al ham shari,

Please consider whether advice should be based on personal experience or hearsay.
Eg, in another recent post you said “I've heard that Naze32 is a very good board”
Would carry more conviction if you said “I’ve used both and this one is better”
No problem in expressing an opinion though, IMHO... ;D

@saikat sir Ive used 4 volt mobile phone charger ( as i mentioned above) to charge lipo battery and imo charging a battery at a slightly higher voltage wont damage the battery as long as the current is lower than the optimal charging current. Its normal high school physics that tells us to charge a battery at a higher voltage than its rated voltage.
@Iyer sir ,  I told my conclusion in that post , that it depends on what you want to do with the multirotor and it was just a suggestion .

@al ham shari

You should've given a little context. A mobile charger would mean a lot of things to a lot of people. Maybe a 12v fast charger as well. Even in the case of a 5V charger, I'd like to know what happens to the state of charging once the cell reaches 4.2V. So, a little clarification is required.

Al Ham Shari - can you let me know the make and model of the 4 volt mobile charger you used ?

this is very interesting because - such a device will never let a cell reach its fully charged state of 4.2 v

 @saikat sir  sorry there is a clarification ,after I checked the charger, it's a 5 volt one, not 4 volt. It is the normal old nokia charger with a pin connector.
@aravind298 I haven't done a test to find out about overcharging. I think, charging it to a higher voltage may damage the battery to some extent.
A fellow forum member @Sooraj Palakkad
told me about charging lipo cell by cell with mobile phone chargers. It was the time I didn't have a proper lipo charger. So, it pretty much worked.

It's about time you speak what you know.

Let's say the charging goes on, when connected to a 5V charger, and the cell gets charged itself to 5V. How's that a situation for you?
I don't think there's a monitoring inside the DC mobile chargers, but the mobiles do.

So, what I suggest is, if you're not sure of what you speak, it's better to shut up.

@aravind298, I calculate the time taking to charge with simple math. So, it doesn't get overcharged. Here is one simple example of charging a 6V 6Ah battery with a 6~6.5 volt 1 amp charger and a 12 volt 1 amp charger .We have to charge the battery for nearly 6 hours in the 6 volt charger to fully charge the battery. If we use a 12 volt charger, we then only need to charge it about 3 hours, since there is an efficiency loss of up to 20% it may vary. So, the same math is applied in this case too. For a 1C battery it's 1 hour nearly at 1 amp

The mobile charger method is never the safest method.