Using batteries 1/2 done in Break In mode?

[purpletiger]

During the first part (low charge) of break-in mode on the Maha c9000, the capacities of the batteries reaches approx 1.6x their rated capacities after a 16hr charge, and then there is an hour's rest, right? E.g Powerex 2700 = approx 3900mA.

My question is, what's to stop me from getting the batteries out before they get to the discharge/rest/charge stage and using them at 3900mA? Wouldn't that be a great way to get more mileage out of my cells? I just know there is a reason you can't, but i cant find anything on it. Please enlighten me

 

[Niconical]

They will have been charged with a total of 1.6x their capacity, yes, but that doesn't mean that at that point they contain 1.6x their capacity.

Imagine you're in a garden filling up a 5 gallon bucket.
You can just put the hose in, turn the water on full and let it fill.
At the end you'll probably notice that you could actually squeeze in a little more.

Now imagine that the break in is you filling the bucket slowly, carefully making sure that the bucket is absolutely filled right to the very top so that not a drop more could possibly fit. You'll get in the full 5 gallons, maybe even a little more if the bucket manufacturer was slightly over in their sizing of the bucket, but however long you drip the hose in there for, you're never going to fit 8 gallons in that 5 gallon bucket.

 

[VidPro]

there seems to be some confusion.
the cell itself has not "accepted" all of this 3900ma of power that was put in, with the low slow charge, the cell eventually is fully charged and the power going in is just wasted. the actual capacity of the cell doesnt change.

With this slow rate, it is within the ability of the cell (usually) to handle this slow overcharge rate , at some point very little of the power converts the chemicals over.

There is some power wasted during the whole charge process, and at the end of the charge process most of the power going in is wasted.
SO
there isnt 3900ma IN the battery, or in capacity, it has just pushed that much twards it

sure you can take it off after the charge and discharge it, but when doing a "break-in" in a controlled situation like this, the discharge is very specific, its low and slow, and therin making it a pretty complete discharge , without it being discharged to low.
so
the machines single battery totally controlled situation discharge is prime for it, there is nothing stopping you from doing the discharge the same way, or just using the battery any way you want, it is just that the machine can do the discharge exactally.

 

[purpletiger]

They will have been charged with a total of 1.6x their capacity, yes, but that doesn't mean that at that point they contain 1.6x their capacity.

Thanks for clearing that up. I guess that's the reason people don't do what i proposed on doing! Silly me....

 

[purpletiger]

there seems to be some confusion.
the cell itself has not "accepted" all of this 3900ma of power that was put in, with the low slow charge, the cell eventually is fully charged and the power going in is just wasted. the actual capacity of the cell doesnt change.

Now everything makes more sense. Thanks VidPro!

 

[purpletiger]

So I've done the full Break In Cycle (slow charge/discharge/charge) and my Powerex 2700 are showing a capacity of

2277, 2306, 2227, 2402

This is below the 2500-2700 range. What do I do now? Use them as is, or try another way to get more juice out of them. If so, which method?

 

[VidPro]

you could go around One More time, but that (as you might have now noticed) is a lot OF time.
use em? lots of this stuff doesnt have the full capacity, and the machine doesnt discharge it 100% , it stops at a nice level that is good for the battery.
when you have more time, or after using them, discharge them before charge again.

 

[SilverFox]

Hello Purpletiger,

Welcome to CPF.

I would suggest that you run another Break-In on them. Those cells usually come in at over 2400 mAh. They look like they may need a little more work to get up to capacity.

If you need the cells for use, you can use them, then do a check later on. You should be able to check them by squeezing in a 500 mA discharge after normal charging. Once again you are looking for a capacity of 2400 mAh or more.

Tom

 

[purpletiger]

you could go around One More time, but that (as you might have now noticed) is a lot OF time.

It sure is!

when you have more time, or after using them, discharge them before charge again.

Looks like that's the best way to go. Thanks Vidpro.

 

[purpletiger]

If you need the cells for use, you can use them, then do a check later on. You should be able to check them by squeezing in a 500 mA discharge after normal charging. Once again you are looking for a capacity of 2400 mAh or more.

Tom

Thanks Tom, i think I'l take the 2nd option ie use them first, then normal charge and discharge to check capacity. If they're still hovering in the low 2200s, then I'll do another break in cycle.