BC-900 refresh mode: To continue discharge cycles, or to terminate "FULL?"

[Turbo DV8]

The charger claims to discontinue additional discharge cycles when there is "no additional increase in measured capacity." Yet, from time to time I see instances where, for example, one AAA cell will attain 802 mAh, then 845 mAh the next discharge, and terminate "FULL" after the recharge. That's an increase of 43 mAh, or roughly 5%, but the charger ceases refresh. Then on the other hand during the same refresh of four cells, another cell attained 821 mAh on one discharge, and 822 mAh on the second discharge, but then began another discharge mode. Why would the charger cease refresh after sensing a 43 mAh increase in the last cycle, but continue the refresh cycles on another cell which only gained an insignificant 1 mAh on the last discharge? Is something other than absolute mAh gain being taken into account, like the slope of the discharge curve, or something, or is this just another BC-900 "personality" trait?

 

[SilverFox]

Re: BC-900 refresh mode: To continue discharge cycles, or to terminate "FULL?"

Hello Turbo DV8,

Interesting observation...

I decided, right after I got my BC-900, that I would prefer to run a series of test modes and keep track of what I was getting for capacity, than use the refresh mode. I could then compare the results and make up my own mind as to whether more cycles are needed. I am pleased that the Maha C9000 is set up this way.

If you are saying that the BC-900 ran 2 cycles and terminated the refresh when the last cycle showed a 5% increase in capacity, then I would think that something is wrong. However, if it ran several cycles, then it could be that it is comparing the last results to the best obtained from an earlier cycle.

Perhaps you could repeat the test and note the capacity for each cycle.

Tom

 

[Turbo DV8]

Re: BC-900 refresh mode: To continue discharge cycles, or to terminate "FULL?"

Yes, it ran two discharges, and terminated "FULL" after the second recharge. I believe I have noticed this behaviour occasionally on my other BC900 also.


How do you run independent tests rather than use refresh, when TEST mode begins with a top-off? You run a complete test, note the capcity, do half a REFRESH (discharge), note the capacity, then terminate the latter half of refresh, and reboot with another test, then repeat?

 

[SilverFox]

Re: BC-900 refresh mode: To continue discharge cycles, or to terminate "FULL?"

Hello Turbo DV8,

I just run repeated test cycles. At the end of a cycle, I let the cell(s) cool down for roughly 30 minutes before starting another test cycle.

Tom

 

[Turbo DV8]

Re: BC-900 refresh mode: To continue discharge cycles, or to terminate "FULL?"

Hello Turbo DV8,

I just run repeated test cycles. At the end of a cycle, I let the cell(s) cool down for roughly 30 minutes before starting another test cycle.

Tom

So you're basically charging an already fully charged cell? Any issues with the cell properly terminating when doing that?

 

[SilverFox]

Re: BC-900 refresh mode: To continue discharge cycles, or to terminate "FULL?"

Hello Turbo DV8,

There are always issues the can arise when charging a fully charged cell. I always monitor the charge to make sure things go smoothly. Usually, the charge cycle is very short.

Tom