Electric Stunt > Gettin all AMP'ed up!
Peaked versus REALLY peaked?
Dennis Adamisin:
OK probably not a topic burning a lot of brain cells - but here goes.
Am charging using a Triton-1 (max charge rate 2.5A) and Equinox then charging my 4S x 3000's through the balance plug. Takes around an hour to reach 16.8V peak. Meanwhile the balance lights on the Equinox indicate that balancer is popping around doing its job, but it seems to take another 1/2 hr or more at 0.1A until it reaches end of charge.
Does that sound normal? Is there any real loss for settling for the 16.8V "peak" and stopping the charge before it shows "END"?
Alan Hahn:
Yes that sounds normal.
My FMA Cellpro charger spends a good fraction of the time at the end trying to balance the cells. Usually I let it do the job, but occasionally, when I don't have a lot of time to screw around, I just pull the battery.
The FMA can charge at 1C, 2C, or 3C (as long as it is 4A or less --a limitation of this charger), but the faster charging time doesn't make a big dent in the overall time because of the balancing.
Mike Palko:
Hi Dennis,
I do the same thing at times with no problems (I use a Astro Flight 109 and Thunder Power balancer combination). Just be sure you don't pull the plug to early because you won't really know what you are taking out and putting back in. What I mean is you can use up to 2400mah from a 3000mah pack. If you don't fully charge you may be taking 2500mah and charging back to only 2900mah. You will know this is the case if your packs start to run hotter than normal.
You can also potentially hurt the packs if you are using their max capacity and the cells are not totally balanced do to pulling the plug early. Even an individual cell that is not totally charged can be drawn below the danger point and slowly weaken the cell until it fails. Of course this is all worst case scenario, but you asked. ;)
More than likely you will be fine.
Mike
Alan Hahn:
I do note that during the final balancing act, the cells really aren't "unbalanced" and are nearly filled to the brink--the FMA gives me a readback on each cell. Sometimes I wonder what it is actually doing--is it just trying to impress me?? y1
Mike Anderson:
It is probable that the cells are still balancing, but down in the 3rd &/or 4th digit, and the FMA (and others with limited screen space) have to round to two digits in order to display all the cells. What it is doing is continuing to charge the cells until the lowest voltage one is up to the cutoff voltage. In the meantime, if any of the other cells start to go OVER the cutoff voltage, it discharges them slightly. The FMA and Imax's are charging the cells in series. I imagine most others do, also.
As to whether it is OK to disconnect before the balancing act is done, the answer is yes. You are only losing a very small current - mine gets down to less than .1 amp during this phase - times a relatively short time - even if it lasts for 30 minutes, you only lose 50 mah by unplugging when the current gets down to .1 amp. This is the basis of Sid Kaufman's LiPo-dapter for field charging - that by cutting off when the total voltage is a certain value, you may not be "peaking" each cell individually, but you get to fly 95% charged cells 15 to 20 minutes sooner. Just be sure to do a complete balance charge when you get home and things will be sitting for a week or so anyway.
Navigation
[0] Message Index
[#] Next page
Go to full version