lipo charging and lifespan

[jokerjustin]

i have this empty lot next to my house so one day i decided to make my own track! well i use my car for about 20 min then go charge it till i want to use it again.. witch is prob about 30 min later. is this bad? i mean by not letting the pack get mostly drained? it puts back about 200 mah but it never really fully charges...? will this reduce the life of my pack or damage it in any way?


another question is what is the maximum charge cycles these packs can take(truerc 4s 8000) and how do u know when you have reached the final days of the pack?

[zeropointbug]

No, that is not bad for them at all, if anything, is good for their cycle life.

As for cycle life, no one really knows because of the various loads that can be places on them, but expect a few hundred cycles IF you take care of them. Lot's of lipo packs don't make it past their first birthday because of a dud pack (puff up, catch on fire), or abuse because of shorts, and physical abuse as well.

If you want cycle life, then you could go with A123 cells, they have incredible lifetime (at least 1000 cycles), durability, safety, and ease of use (fast charging, balancing not essential, not sensitive to overcharging)

[jokerjustin]

well i take pretty good care of them. i made a box lined with foam that mounts to the side of my revo. i always balance and have never shorted them out. they nerver get above 100 degrees. ive had them for about 3 months now and they have been running strong..... so theirs no way to know if they have reached their end without them exploding or puffing?

[zeropointbug]

There really isn't an "end" for batteries, you decide when this end is... from the time you buy lipo's and start using them, their internal resistance goes up, and mah capacity retention goes down, after every cycle, bit by bit. Standard ratings go by the 'end of life' at the point where only 80% of it's original capacity is left. But, as well, the internal resistance goes up too, and performance is a product of resistance (chemical resistance) x mah capacity, so performance will go down exponentially, unless I am mistaken.

A123's are a littel different in cycle life aging, they are the first battery chemistry to actually have their internal resistance go DOWN over time, but of course their capacity goes down as well... so if you look at cycle life charts of them, their performance stays the same over their entire life! Only mah capacity is reduced. Although, they don't perform like high end lipo's, and they only have one cell size, I love them, and have been an early adopter from the start.