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What's the maximum cell imbalance (max. V - min. V) you'd run or store your LiPo with?
I currently don't have any poorly balanced LiPos, but this would be good info to have.
iCharger is one of the top in the industry and does a good job of balancing. It sounds like that one might just be at that point of retirement...Kinda bringing this thread back from the dead... at least it's still warm.
I have a v3 Kraton and have 2 Lectron Pro 6S packs; 5200mah, 50c. They're both the same age as the truck, 3.5 years old. One of them recently developed a .04v imbalance on cell 1, at lest at storage (3.85v). I honestly don't think either pack has more than 15-20 cycles, they're just old.
I've been trying the last couple of days to even the pack back out by first discharging to 3.7v (per cell), then back up to storage at 1amp, then yesterday to 3.5v and this morning back to storage at .3a. The .04v imbalance is consistent throughout each cycle, up and down, and at both ends.
I use iCharger 206b's and it shows the same on either charger, plus the other pack is fine, within .003.
Should I bite the bullet and retire this pack?
You could always try charging those 2 cells individually.Technical aptitude applies here however. But it can work. You never stated what the IR's were when those cells were found lower than the others. But honestly if it is bricked, it is your own fault. Crap happens. Hopefully never happens again.I have a pair of 6750mah 3s and by mistake i drained one down to low 3v range
two of the cells cannot reach 4.2v anymore. they get upto 4.15v. only one charging so far and did not notice any battery temp differences. not warm or anything. That said, i would go more than 0.5v...and even that is kind of allot.
So I'm impatient. I ended the .3a charge at around 3.9v per cell and balance charged the pack at 2C (10.2a). All cells within .1 at the end. Highest IR was 5, lowest 3. It took a good 35 minutes to finish once it switched to CV. I forgot how much energy was put in though.
Ran the 6S Kraton out in the field to LVC (8 minutes) and got the pack nice and warm. Immediately brought it in and storage charged at 2C. When done, IR was 2-1-1-1-0-0 after 5 minutes.
I'll keep it for a while, but will be looking for new packs eventually. It seems I might have better luck find "good" 3s packs than 6s though.
I prefer to charge or storage charge my packs after a 40 min "cool down" at a minimum. Even if the pack is only slightly warm after bashing. Balance cycle always is the longest portion of the cycle. Normal.So I'm impatient. I ended the .3a charge at around 3.9v per cell and balance charged the pack at 2C (10.2a). All cells within .1 at the end. Highest IR was 5, lowest 3. It took a good 35 minutes to finish once it switched to CV. I forgot how much energy was put in though.
Ran the 6S Kraton out in the field to LVC (8 minutes) and got the pack nice and warm. Immediately brought it in and storage charged at 2C. When done, IR was 2-1-1-1-0-0 after 5 minutes.
I'll keep it for a while, but will be looking for new packs eventually. It seems I might have better luck find "good" 3s packs than 6s though.
I've always been little confused by this. From what I understand that is the "resting voltage". I've also seen different articles and postings with conflicting values, so I just follow what's on the battery.They store best at 3.80-3.85 volts per cell. This is the condition they are in when new out the box. Give or take. I specifically set my ISDT Charger to storage charge mine at 3.85v/cell. If they sit unused for months, I wil check them and put them on the charger for anther Storage charge cycle. May take only 2- 3 mins to bring them up to 3.85 v/cell again. Lipos sitting unused for long durations always lose volts. Don't neglect them.
The reported maximum cycles is in a controlled environment. It's like the old MPG ratings, where you could buy a Big Block that got 20MPG. What they didn't tell you is that was down hill in a hurricane.3.80-3.85 / cell storage volts seems to be the concensus. Give or take .0X v is negligeable.
Again, lipos new out the box are in this range. And for a reason. So they sit stored in inventory best for the consumer when ultimately purchased. It's just how lipo chemistry works.
I have received Lipo cells that were far below. They are questionable and I have returned them. A sign of bad production runs, bad cells or they just sat very long in inventory. New, but very old stock. Food for thought. Always check lipo's well right out the box and immediately. Lipos can be a mixed bag sometimes, regardless of price and brand. Bad ones just happen from time to time. Just takes one bad cell to ruin a new pack.
Age, regardless of how many times cycled as well as number cycles is what depletes a lipo. And High humidity is a lipo's worst enemy over its lifespan.
I find my lipos on average only last approx. 50-60 cycles before they start to peter out. Some still work ok. Just not the best run run times, no matter the brand or price. Proper and consistent Care and Feeding promotes a longer life.
The lipo industry claims they should provide way more use/cycles out of them. But that is in a perfect environment. We really abuse the crap out of our lipos in reality. Consisering how weactually drive our rigs and all, and the extreme environments we use them in as well.
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