RC India

i just had a prob vth a lipo 1000mah 3s.... All cells in it only charge till 4.15V then charger will show fully charged.. Same prob happened to another 2200mah3s lipo of mine... They both used to charge till 4.20V. i check it using the samm 2s-6s voltmeter..
Please advice...

Which charger ?  Seems like an accuracy issue.

I use the turnigy max 80W

The charger used to carge all cells to perfect 4.20V i dont know what happened all of a sudden.... The same day i lost my mystery 80amp esc.......... it was really a bad day...........

maybe battery is on its way to die, do u use a data logger?

how do u store your battey, empty? charged? or storage voltage, temp

do u have control on how much mah u put in to the battery?

ohnestly i am not a big fan of these cheap chargers.

batteries are to expensive, i am using big packs and want to have control over the batteries , so i am logging once in a while to c the performance and using hyperion chargers connected to pc and just tag each battery and have full documentation on each charge and u can compare how  balance and ir is changing .

Hai... I store the lipo at abt 11.6v.. The charger charges other lipos correctly... While charging the charger shows the voltage of 4.20 fro each cell but the vot is shoen as 4.15V on my small lipo voltage checker... is there any way i can bring back by lipo.. they are not much used.

Charge your batteries at 0.1 amps. This will take long but will balance it well. Use the balance mode to charge with the balance cable connected. Most of the chargers like Turnigy, HK, Hot Power, Imax etc will stop charging when the current drops to approx 1/20 of the configured current. During the charging process, monitor the voltages of the cells by pressing the INC button once.

Slow balance charge should balance the cells upto 4.2v each. Also, what DMM are you using to check your cell voltages? Cheap low quality DMM are not very accurate but do give a fair idea.

This is nothing but a calibration issue.

Calibration issue surely!!
Calibrating your chargers voltage is very simple on turnigy chargers. Does your charger have 4 buttons below the LCD display, If so, I can guide you through the calibration procedure.
You have to confirm some thing though -
That the charger shows 12.60v (4.2v/cell) after charging has stopped, but the volt meter shows only 12.45volts(4.15v/cell). If you can cross check with another reliable volt meter that it is Actually 12.45, then calibration must be done...

Though you will be able to calibrate only the main ports on Turnigy chargers (specailly Accucell 6)
The sad part is that the balance ports cannot be calibrated by end users.

Only ichargers and HK Variable 6 chargers have this capability.

The charger shows 12.6V 4.20V/cell after full charging... but my voltmeter shows only 4.15-4.17V/cell.. it showed the same for both my lipos.. but befor it used to show fine....

Yes my charger has 4 buttons below the LCD screen

For calibrating this charger follow these steps:

NOT SURE IF THIS WILL WORK ON TURNIGY 80W CHARGER. BUT SURELY WORKS ON ALL OTHER 50W CHARGERS INCLUDING ACCUCELL ETC.

1.) Power off the charger.
2.) Press and hold the "dec" and "start" buttons.
3.) Power on the charger. (you will hear 3 beeps in a row). Keep the buttons pressed.
4.) You will enter into the calibration screen where the voltage detected by the charger is displayed on the screen (voltage on output leads).
5.) Attach any battery to the output leads of the charger.
6.) Using a digital multimeter, correct the reading of the voltage by pressing "inc" or "dec" buttons till the reading matches with that on the multimeter.
7.) Press "Stop" when you are done.
8.) Your charger is calibrated now.

Only the main port can be calibrated using these steps

Hai saurabh... Is is possible that my charger is showing voltage correctly and my voltmeter is wrong... and if i correct my charge by .15v then when i charge my lipo will it charge to 4.35v (real value) and show 4.20V???

yes... very much true... thats y you need a well calibrated Digital Multimeter. Thats why I do not recommend a cheap Chinese multimeter. They are usually not very well calibrated. I suggest you be on the conservative side. Try borrowing some DMM from your friends and check the reading for concurrent results.

If you wish to buy one, then Fluke is a reliable brand. I got my Fluke 115 DMM for Rs.8000 here in Mumbai.

Hope this helps.

k.... I will do some charging on my other lipos and pin down where the prob is.. Is it with the charger or lipo... thanks Saurabh.......
It was really helpful....

Sure Sreedhar... :)  :thumbsup:

What I would suggest is to take readings from different Multimeters and see if you can derive a concurrent reading. Use that as a base to calibrate your charger.

Calibration is a serious process. People have had serious accidents due to Lipo flameout coz of overcharging due to improper calibration on their chargers. So be careful and all the very best. You can reach me at 9004548889 incase you need any help. :thumbsup:

i will surely be in contact yar.... i will do as you suggested..