RC India

RC Equipments => Batteries and Chargers => Topic started by: santhosh-r on December 10, 2014, 05:45:24 PM



Title: Turnigy accucel-6 charger voltage reading and charging error
Post by: santhosh-r on December 10, 2014, 05:45:24 PM
I have been using the Turnigy Accucel-6 for about 1.5 years and suddenly the Cell 1 voltage and the total pack voltage reading in Balance charge mode shows a huge error 1.35V vs 3.85V actual.I have good experience in electronics and I'm currently trying to find the problem using the circuit that I found online for B6 charger.I would like electronics experts to help me to accelerate the repair process.
As far as I guess the resistor divider network used to measure the pack and cell voltage must have malfunctioned or the ADC channel of the IC must have been damaged.

The video footage is available at https://www.youtube.com/watch?v=IUWZWrrvW7E (https://www.youtube.com/watch?v=IUWZWrrvW7E)


Title: Re: Turnigy accucel-6 charger voltage reading and charging error
Post by: akhilzid on December 10, 2014, 06:01:38 PM
just to make sure.
did you check the battery health is enough?

Edit: did you check the voltage in Normal charge mode?


Title: Re: Turnigy accucel-6 charger voltage reading and charging error
Post by: santhosh-r on December 10, 2014, 06:13:47 PM
I checked everything with a multimeter.The problem is with the charger. When in normal charging mode the voltages of each cell is correct but in Balance mode the voltage has huge error.

P.S. - all batteries are good and not puffed and have taken very good care.


Title: Re: Turnigy accucel-6 charger voltage reading and charging error
Post by: akhilzid on December 10, 2014, 06:23:50 PM
so the discharging resisters bridge may be shorted, try checking resistance of each bridge.

Edit: you can confirm that by connecting multimeter to any other balance charging port(1st and 2nd pin) and measure voltage while balance charging.


Title: Re: Turnigy accucel-6 charger voltage reading and charging error
Post by: santhosh-r on December 10, 2014, 08:41:07 PM
@akhilzid - tried your suggestion , actual battery voltage didn't drop as measured at the balance port of the charger during balance charging.
Another problem arose - when continued to charge at normal charge mode after a few seconds it shows connection break.

When I tried fast charge mode with a multimeter in ammeter mode in series with positive wire  ,there was no current flow but the charger showed that current was flowing.

These problems made me doubt the current measurement IC or the output MOSFET.


Title: Re: Turnigy accucel-6 charger voltage reading and charging error
Post by: akhilzid on December 10, 2014, 09:00:09 PM
you may look at this http://www.youtube.com/watch?v=W-GP-7wV55M#ws (http://www.youtube.com/watch?v=W-GP-7wV55M#ws)


Title: Re: Turnigy accucel-6 charger voltage reading and charging error
Post by: santhosh-r on December 13, 2014, 06:10:13 PM
Thanks akhilzid for your help.

The problem was not with the PCB traces on the Balance plug board.The problem was found to be a Open 0.5ohm resistor connected to the output mosfet.
I found it when I was testing the voltage levels on the MOSFET pins during live operation of the charger.

I coudn't find the exact replacement but could find the same value but in a smaller package.So I decided to connect it in the following configuration.

              0.5ohm              0.5ohm
       ____/\/\/\/\_________/\/\/\/\______
       |                     |                          |
------|                     |                          |--------
       |___/\/\/\/\____|____/\/\/\/\______|
             0.5ohm             0.5 ohm


Title: Re: Turnigy accucel-6 charger voltage reading and charging error
Post by: santhosh-r on December 13, 2014, 06:11:45 PM
Different modes and current value error