Trickle Charge methods

[koala]

I recently bought a battery charger TG1000. Samya is the manufacturer. The charger is an intelligent charger with minus Delta V voltage detection, temperature monitoring and trickle charging. The charger works okay for 1800mAh cells and below. However, it will overheat and shutdown automatically(after 15minutes) if I try charging the newer 2500mAh cells. This is fixed by drilling 26 /ubbthreads/images/graemlins/ooo.gif 5mm vent holes all around the pvc casing. The electronics build is medium quality with a thermistor in the middle of the circuit board.


Yesterday, I was interested with the charging current so I hooked up an analog amp meter in series with the cell and charger. Powering up, red LED comes on, the meter jumped every 1.4 seconds from 0 to ~2200mah. I guess it's trying to detect the cell type? After around 1 minute or 2(did't time that) the charging process started with the meter jump every 1.4 seconds and current from 1000 to ~2200mah. This process goes on for a long time.

I am quite surprised that it doesn't use constant current charging. After a while I begin to realise that the rest is probably for monitoring the minus Delta V voltage?

The charger finish off with a green LED indicator. The meter jumped every 5.2 seconds from 0 to ~2200mah could this be the tricle charging? I suspect this will overcharge a cell sitting there for prolonged period, however the temperature of the cell out of the charger when trickle charge is very cool compared to a charging cell.

Is this a silly trickle charging charger? /ubbthreads/images/graemlins/confused.gif

 

[Brock]

What it is probably doing is taking that 2200mA and moving it from cell location 1 to 2 to 3 to 4 then back to 1. So it puts out 2200mA all the time just rotates through the cells. This is actually quite common in 4 cell chargers.

On the MAHA 401 you can hear a quite clicking as it switches charging channels.

 

[koala]

Hey Brock,
your right! I put two amp meters in series with two charging cells they swing alternately. Then I add a third cell the swing slow down to about 2.5 seconds each.

 

[cobb]

I know from use of wheelchairs and car chargers, most are only 90% done and you need the trickle charge mode to get that extra 10%. For one make of wheelchair I was told to cycle the charge when it is done to do this.

 

[RussH]

I suppose that the trickle charge is a low duration PWM charge. I think the CCrane charger does that.