Hello everybody, I have imax b6 Ac charger.
When I try to charge my lipo (3s 15500mAh) it restarts and does not charge the lipo, it is also detecting only two cells but in the multimeter it shows 10.02volts
Please tell me how to restore it .

1.What mode and current did you set for charging?
2.What is the input supply voltage and power rating of adapter if applicable?
3.Are you able to charge other 3S LiPos?

Post pics/video if possible

1)I tried both balance and charge  mode,
2)It has ac power supply.
3) no , I also tried 3s 2200 mAh but failed.

This is the video:

This might seem insane, try setting as 4S in charge mode and check whether it is detecting as 3S. Another way, if your charger supports internal resistance measurement, try that.

@pranavk09,
From the video it seems the balance plug is plugged into the 1st port (top right).
Is it so?

If so, then your lipo must be 2s, as a 3s balance plug just cannot fit into this slot!

Can you post a pic of the lipo and its balance plug?
How many wires in the balance plug? 3 or 4?

@K K Iyer sir it is 3s lipo and balance plug has 4 wires as in photo attached.

@santhosh sir
After selecting as 4s it still shows as 2s.

You said the multimeter shows 10.02v.
Possible if 2 cells at +4v each and one below 2v.
B6 detecting only 2 cells could be due to one cell being below detection threshold.
Can you check each cell voltage separately using the multimeter on the balance plug?
Please be VERY CAREFUL!

Sir now total voltage :8.69
Cell1: 3.15
Cell2: 2.99
Cell3: 2.48

I fear that your lipo is dead.
There are ways to revive, but as they are not too safe, i am not indicating.

One thing you can try though.
If you have the means to charge ONE CELL AT A TIME, try it AT A VERY LOW RATE, BELOW 1/10C.
Once each cell is up to ~3.3-3.5, the B6 should be able to recognise them.

By the way, when B6 shows R=2s and S=3s, you are supposed to CANCEL, not continue. Else you get unpredictable results. Like 26v showing in your video...

Sir my friend had an emax 2-3 cell Ac charger (from rcdhamaka) will that work initially.

There are two issues involved, which please do not mix

1. If what you want is to fly your model, forget this lipo and get a new one. And see that you never let it go below 3.5v per cell.

2. If you are curious about how to fix this lipo, you can charge it at a low rate, one cell at a time, even with your B6. If you have the experience to do this SAFELY, you will also know how. Otherwise not worth the risk. Try to AVOID.

Remember: Fiddling with lipos is a BIG FIRE RISK.
Regards.

Thank you sir I'll  go for a new lipo

The charger is not working with other good batteries!!!!
Help needed.....

Tried another 3s 2200mAh but the charger did the same
Now it detecting 3cells but blanks as soon as confirmed charging.

This is a vague statement.
Please be specific.
We already know that your original lipo is over discharged.
Now what lipos did you test, and what was the result?
Not clear what you mean by charger is not working with other good batteries.
Not switching on?
Not detecting cells correctly?
Not entering charge mode?
Maybe your B6 is bad, but please check step by step, and post result of each experiment.
Then someone will spot the real problem and offer the correct solution...

Incidentally, we have had a similar problem recently. Solved as the LHS took up the matter with the source, and gave us a new piece!
Who did you buy it from? What do they say?

Sir  I used another lipo 3s 2200mAh and also 3s 1500mAh 
It connects well . when I started charging on balance mode it shows 3s (I.e. it detecting all three cells) but not charging the battery instead it restarts as happened in video attached above.

I bought it from one of my old friend so don't know the exact vendor of the charger.
The charger Also restarts when used at charge mode.

I can clearly observe one thing, when the charger is turning ON the output MOSFET, the input voltage sags and the microcontroller resets, which also turns OFF the MOSFET. This whole process repeats whenever you try to charge. I want to confirm if the same happens when you put it in NiMh / Pb charging mode. If it happens in both other cases, then you might need to try powering the charger from an external 11~17V supply with adequate current rating of 2A or more.

I had a similar problem with my Accucel charger wherein the charger restarted the moment the charging was initiated. The issue turned out to be the input 12v supply. I changed to a proper 12v 5amps power supply from a SMPS. The problem was solved. SMPS could not provide the required amps. I know your charger has inbuilt power supply. But try if you can disconnect the same and use an external power supply.

@santosh
It does not happen with NiMh battery.
Since charged my cars igniter.

It might have worked for your car igniter battery, since it will be charged at ~1.5V @ ~500mA, and this wouldn't have loaded the inbuilt power supply enough to sag the voltage. Try this for any 3S LiPo, choose balance mode, set @ 3S and 0.1A charging, if this works, then the problem is clearly with the inbuilt SMPS.

It is also not working even when connected to 3sLipo at balance mode on 0.1 A

1. Which lipo?
The one with two cells below 3v?
Or with a healthy lipo?

2. Do you have any 2 or 4 cell lipo?
Try them. If they get charged, then we'll know the problem is in the 3s port...