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Help! Fromeco 5200 LION capacity

Trump

30cc
I was wondering what you should see on a battery cycle of a healthy Fromeco 7.4 volt 5200 LION battery pack?
Basically, if you charge it and discharge it with a cycler, what should come out and what should go in?
I am using 7 volts cut off and 6 volt cut off as the basis. .5 amp discharge.
 

stangflyer

I like 'em "BIG"!
A Fromeco LiIon really doesn't need to be cycled as the chemistry does not require it. However if doing this for general knowledge, normally a fully charged-relatively new LiIon 5200 should come out minimum of 90% of total capacity. +/-. If fully discharging, you should never let the total voltage drop below 3.0 to 3.1 volts per cell. i.e., 6.0 to 6.2 volts. That is the only voltage that is a true parameter for "cycled" LiIon's. I have been running Fromeco's in my planes since I switched over from Nimh five years ago. I have done one cycle on one plane of the five I use them in. In five years, I have seen no point in cycling them. My 260 is in her fourth full season since putting the Fromecos in her new. I keep a flight and charge record on all my planes. In four years, there has been no change with any of them regarding amount of normal usage verses what I put back in them prior to flying. I suppose at the end of this season I may have to do a cycle on the 260 batteries just to see what their total capacity is now after four years. According to Kurt from Fromeco, I believe he told me that as long as they retain minimum of 80% of total value, they should be fine. I myself don't think I would use them if they showed less than a minimum of 80% total value. At roughly 140.00 for two 5200 LiIons, that is a pretty cheap insurance policy even if they will still hold a good charge for a few flights.
 

stangflyer

I like 'em "BIG"!
And yes...Jetpainter is correct. The 7 volts is too low for a fully charged LiIon. A fully charged and healthy LiIon 7.4 pack should max out at 8.4ish volts.
 
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dhal22

GSN Sponsor Tier 1
I just record what gets put back in . A couple of flights uses 600-700 mAh and there's 10,400 on board.
 
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acerc

640cc Uber Pimp
My Li-Ion's are over four years old, I do a total discharge every six months just to check their total capacity ability. At their age they still cycle nearly 100% of their capacity. Normal everyday use is just charge and fly, 8.4v fully charged and can fly for several flights before even thinking about it. I do check them after each flight just to be on the safe side.
 
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