RC India

General Topics => Chatter Zone => Topic started by: sreekumar on January 04, 2019, 04:04:21 PM

Title: Lipo battery
Post by: sreekumar on January 04, 2019, 04:04:21 PM
My new 3s lipo connected my esc some electric spark came and as dead..I checked my lipo with lipo checker it shows only 2 cell voltage..I try to charge it shows 2 cell charging.. I checked its main lead with multimeter it doesn't show any voltage  what happend my lipo..?
Title: Re: Lipo battery
Post by: newpg202 on January 04, 2019, 05:16:50 PM
I am a little bit confused with this

"I try to charge it shows 2 cell charging.. I checked its main lead with multimeter it doesn't show any voltage"

What charger you are using?
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 05:21:10 PM
B3 AC
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 05:27:07 PM
Lipo checker detecting only 2S and all voltage is normal for 2cell
Title: Re: Lipo battery
Post by: newpg202 on January 04, 2019, 05:43:46 PM
OK,
Try This with caution!

1. Identify the cell that seem to be dead
2. Use a multimeter to check that cell only
3. If you see any voltage, it is good.
4. If the voltage is somewhere below 3V the charger is not able to charge that cell!

5. Now the dangerous part: Do with caution!!!!

5i. Find a 5V/2A DC Output, a stopwatch (you can use mobile), some wire to connect the battery, multimeter.
5b. Connect the charger (MATCH THE POLARITY) with the dead cell and charge it for 15 sec. NOT MORE THAN THAT. (use the stopwatch). Then measure the voltage, if 3V or higher, you are done! Connect it with your lipo charger. It should work.
5c. If the voltage is still below 3V use the process as 5b. and repeat till it shows 3V or higher. After each charging the voltage should rise. If not rising you have a damaged cell! So no luck.


6. If no voltage shown, the possibility is internal soldering may be open (You have reported spark!) open the battery and check for that.

Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 06:00:00 PM
Is 5V is connected to balance lead of no voltage cell.  ?
Why it main lead shows any voltage..?
Is lipo checker will detect all cell even it has no voltage..?
Title: Re: Lipo battery
Post by: ashok 2010 on January 04, 2019, 06:48:50 PM
3 S connection try with caution
don't short pins or will result in fireworks
regards
Title: Re: Lipo battery
Post by: newpg202 on January 04, 2019, 07:23:03 PM
Sorry. I overlooked your last message. as lipo check shows only two cell it is highly possible that a solder joint is open.
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 07:27:48 PM
If solder broken ...I have to open lipo and resolve it .!  is it risky..
Main lead also not showing any voltage...
Title: Re: Lipo battery
Post by: newpg202 on January 04, 2019, 07:50:04 PM
No risk if done carefully. Keep in mind two things. 1. Avoid any chance of short circuit. Desolder one wire tape it then another. 2. Don't over heat the lipo while soldering. Clean the leads with alcohol or acetone first. Rub it gently with sand paper and apply good flux and solder with a good iron. A little tricky job. And yes please don't try if you are not confident in your soldering skill.
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 08:01:18 PM
Quote from: sreekumar on January 04, 2019, 04:04:21 PM
My new 3s lipo connected my esc some electric spark came and as dead..I checked my lipo with lipo checker it shows only 2 cell voltage..I try to charge it shows 2 cell charging.. I checked its main lead with multimeter it doesn't show any voltage  what happend my lipo..?

CAUTION:
IF YOU DONT HAVE EXPERIENCE WITH ELECTRONICS, ESP LIPOS, DO NOT TRY TO REPAIR LIPOs.
SO DONT ATTEMPT ANY REPAIRS TILL YOU HAVE EVALUATED THE PROBLEM.

That said, can you just connect your lipo checker to the lipo and post a video of what it shows?
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 08:09:58 PM
Sorry..I just open it.. will u check the company soldering
Title: Re: Lipo battery
Post by: tictoc21 on January 04, 2019, 08:19:58 PM
As now you opened it just chk voltage at each cell.
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 08:24:07 PM
Something seriously wrong.
Did you solder some wires, or did it come like this?
Pl post side view so we can see battery make and specs.

The wrong polarity of the balance plug is a dead giveaway.

I'll stop here as others too are trying to help...
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 08:32:36 PM
Yes sir I just oped it it is company soldering..its red balance wire goes to red.....its shipped from electronics comp..my 2 esc dead..
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 08:47:20 PM
Image
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 08:49:06 PM
Inage
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 08:54:41 PM
What to do ..sir  its company soldering polarity is wrong....any repair is possible..
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 08:57:25 PM
Quote from: sreekumar on January 04, 2019, 08:32:36 PM

its red balance wire goes to red..

Does it?
Obviously not!
Title: Re: Lipo battery
Post by: newpg202 on January 04, 2019, 09:02:17 PM
It seems wrong soldering. Check with a multi meter with individual cell leads for the polarity. It should be as per the drawing shared by Mr Ashok 2010.
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 09:03:03 PM
You didn't post a side view to show make and specs.
Pl do.
There are many experienced members near you who can check your lipo.

Failing that, you can send it to me...
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 09:04:48 PM
Sorry sir its red balance goes to black...main lead
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 09:32:53 PM
Perhaps assembled by someone locally.
Unlikely that a manufacturer would make such a mistake.

Await side view showing make and specs...
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 09:35:31 PM
Image
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 09:36:40 PM
Individual cell show 3.8 volts
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 09:42:13 PM
Looks ok.
Now show us what the lipo checker says
Title: Re: Lipo battery
Post by: newpg202 on January 04, 2019, 09:51:53 PM
Are all the individual cells showing 3.8 v?
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 09:57:49 PM
Quote from: newpg202 on January 04, 2019, 09:51:53 PM
Are all the individual cells showing 3.8 v?

My question is different.
What does the lipo checker say?
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 10:06:41 PM
I connected lipo checker it shows first 2cE then ALL then 7.62 .. .3.81 and 3.81
Title: Re: Lipo battery
Post by: sreekumar on January 04, 2019, 10:27:39 PM
Its main lead no shows any voltage in multimeter
Title: Re: Lipo battery
Post by: newpg202 on January 04, 2019, 10:41:59 PM
Check each cells individually directly on the leads for voltage and polarity, and refer Mr Ashok 2010's diagram. You can find the fult.
Title: Re: Lipo battery
Post by: K K Iyer on January 04, 2019, 10:59:21 PM
Withdrawing...
Title: Re: Lipo battery
Post by: taksh on January 05, 2019, 12:04:01 AM
@sreekumar sir
which lipo checker u are using?
Image...?

Title: Re: Lipo battery
Post by: tictoc21 on January 06, 2019, 12:09:26 PM
Quote from: sreekumar on January 04, 2019, 08:49:06 PM
Inage
Quote from: sreekumar on January 04, 2019, 08:49:06 PM
Inage
You have just missed the one cell of battery to connect the main lead.
Title: Re: Lipo battery
Post by: tictoc21 on January 06, 2019, 12:11:35 PM
Chk the pic
Title: Re: Lipo battery
Post by: tictoc21 on January 06, 2019, 12:13:46 PM
The negative main lead is connected to 2nd cells negative  or you can say 3rd cells positive. Hence you are able to measure the the voltage of 3rd cell.
Title: Re: Lipo battery
Post by: tictoc21 on January 06, 2019, 12:15:15 PM
@k k Iyer please look into this image. The balance lead connection are also wrong.
Title: Re: Lipo battery
Post by: tictoc21 on January 06, 2019, 12:21:20 PM
The corrected balance and main lead according to me are shown below
Title: Re: Lipo battery
Post by: newpg202 on January 06, 2019, 12:27:56 PM
 :salute:Nice job tictoc21.
Title: Re: Lipo battery
Post by: tictoc21 on January 07, 2019, 09:25:47 AM
Thanks newpg202
Title: Re: Lipo battery
Post by: sreekumar on January 07, 2019, 09:45:09 AM
Yes discovered the issue....middle to last cell soldering there is a gap...I checked individual cell all ok and I touch with wire to plus and minus of middle and last cell.. I got 3s voltage in my checker....thank for all who helped me   ....I didn't soldered it..I want some help in soldering..
Title: Re: Lipo battery
Post by: sreekumar on January 07, 2019, 09:55:19 AM
One more issue...in main lead they used red wire to connect negative  and black wire to positive...may be that is the reason my esc dead..if I connect my esc to battery  its positive goes to negative and negative goes to positive.
Title: Re: Lipo battery
Post by: tictoc21 on January 07, 2019, 09:59:20 AM
Yes chk it on multimeter, i assumed red wire as positive. Please soldered it properly.
Have a good day.
Title: Re: Lipo battery
Post by: sreekumar on January 07, 2019, 10:01:07 AM
Image