Lipos: storage charge or 'as flown'?

[aschen]

sematics aside, are packs at risk for starting fires if they are not connected to anything, have not be dropped or impacted, or shorted recently?

[KiloXray]

I don't really understand the argument of "if you storage charge, it takes less time to charge them up when you go to fly them". Charge time is charge time. You either spend the time before flying, or after flying. You aren't "saving" any time by storage charging.

I fly my expensive packs down to about 3.8ish and call it a day. They sit until I fly again. I almost always charge at 5C, but I balance charge every single time.

My cheap ass packs, anything less than $10 or so, I dont really bother with being careful. I fly them to 3.75 or so, and let them sit. I charge at super high charge rates, but again, always balance charge.

The only time I bother with going to a storage charge is if I miscalculated something. ie...I flew one lower than intended, I charged too many and didnt have time to fly them, etc.

[Pitch-Itch]

Originally Posted by KiloXray

I don't really understand the argument of "if you storage charge, it takes less time to charge them up when you go to fly them". Charge time is charge time. You either spend the time before flying, or after flying. You aren't "saving" any time by storage charging.

I fly my expensive packs down to about 3.8ish and call it a day. They sit until I fly again. I almost always charge at 5C, but I balance charge every single time.

My cheap ass packs, anything less than $10 or so, I dont really bother with being careful. I fly them to 3.75 or so, and let them sit. I charge at super high charge rates, but again, always balance charge.

The only time I bother with going to a storage charge is if I miscalculated something. ie...I flew one lower than intended, I charged too many and didnt have time to fly them, etc.

It's just semantics. No, you aren't "saving" any time. You're just getting some of the charge out of the way on the front end.

That's probably what they mean.

[DominicD]

Originally Posted by KiloXray

I don't really understand the argument of "if you storage charge, it takes less time to charge them up when you go to fly them". Charge time is charge time. You either spend the time before flying, or after flying. You aren't "saving" any time by storage charging.

I fly my expensive packs down to about 3.8ish and call it a day. They sit until I fly again. I almost always charge at 5C, but I balance charge every single time.

My cheap ass packs, anything less than $10 or so, I dont really bother with being careful. I fly them to 3.75 or so, and let them sit. I charge at super high charge rates, but again, always balance charge.

The only time I bother with going to a storage charge is if I miscalculated something. ie...I flew one lower than intended, I charged too many and didnt have time to fly them, etc.

You are 100% right. Usually I try to charge my packs the morning of flying, not the night before (something i feel is important). Since I want to get to the field as soon as a I can instead of watching my charger ...

[KiloXray]

Originally Posted by DominicD

You are 100% right. Usually I try to charge my packs the morning of flying, not the night before (something i feel is important). Since I want to get to the field as soon as a I can instead of watching my charger ...

I can understand that.

I dont spend anytime charging before, or after. I charge at the field. I set the gen and charger up first. By the time I am ready to fly my first pack, they are done charging. @ 5C, charge times are usually around 12-15 mins.

[DominicD]

I field charge too, but I like to get to the field with the first batch of charge.

[Staticxd00d]

I've been storage charging when I get home from the field... But after reading this, I think I'll just start leaving them unless I don't plan on flying for a good long time.

[mba83]

If the pack is 3.75 or over, I don't storage charge (unless I have time and feel like having all packs be at the same voltage for the next charge session).

BTW storage charge voltage, to me, is anything between 3.8V and 3.9V. And even 3.7V is OK for short term storage, IMO.

[TheBum]

Originally Posted by DominicD

You are 100% right. Usually I try to charge my packs the morning of flying, not the night before (something i feel is important). Since I want to get to the field as soon as a I can instead of watching my charger ...

That would require getting up earlier. I have a hard enough time getting up in time to get to the field by 9:30 or 10:00. I am NOT a morning person.

With regard to the OP's question, I don't storage charge unless I've really run down a battery, and even then it depends on the demand the model puts on the battery. If it's a battery in one of my larger helis, I'll do a storage charge if the voltage is below 3.7V/cell or so, but it's very rare for me to run one down that low. For my mini quad, I don't bother.

[Luvmyhelis]

Originally Posted by TheBum

That would require getting up earlier. I have a hard enough time getting up in time to get to the field by 9:30 or 10:00. I am NOT a morning person.

With regard to the OP's question, I don't storage charge unless I've really run down a battery, and even then it depends on the demand the model puts on the battery. If it's a battery in one of my larger helis, I'll do a storage charge if the voltage is below 3.7V/cell or so, but it's very rare for me to run one down that low. For my mini quad, I don't bother.

I am def not a morning guy either. And in some cases this spring it has been a week or two between outings due to weather. So I do storage charge after my outings now when I get back home. Only because I take out 8 fully charged sets of large 12 and 14s packs for all four of my helis. So it takes an entire eve and morning to charge all of them from scratch. But starting from the storage level it seriously cuts down the time by roughly 2/3rds. And talking with Mark at ThunderPower, who affirmed to me not to charge beyond 1 1/2 C if you want your packs to survive for very long. He ascribed the high C charge rates to a myth, as it severely shortens the battery life in virtually every brand they researched. I just had this phone call!

Most my batts are three years old now and performing well. For those who think I am easy on them. Try running KDS gen 3 motors at full tilt. Which I do.

Bottom line, the storage charge saves me time before the outing. And takes time when I have it earlier.

[seefest]

If I had to charge at 1.5C I would have switched to nitro YEARS ago.
Thankfully I get 200-250 cycles from my packs charging at 4-5C which is fine for me. Field charging with three sets of packs for each heli works well and allows me to fly interrupted for as long as I'm able.
For me, time is money, so I'm willing to sacrifice a small amount of longevity(still not proven to me BTW) for the convenience of flying back to back at a whim.

[Pitch-Itch]

Originally Posted by seefest

If I had to charge at 1.5C I would have switched to nitro YEARS ago.
Thankfully I get 200-250 cycles from my packs charging at 4-5C which is fine for me. Field charging with three sets of packs for each heli works well and allows me to fly interrupted for as long as I'm able.
For me, time is money, so I'm willing to sacrifice a small amount of longevity(still not proven to me BTW) for the convenience of flying back to back at a whim.

Yep this is how I feel as well.

I've 3c charged two 6s 4400s for over 150 cycles now.

IRs are less than 2 on all cells. I think that if fast charging does harm the packs, the effect is so minimal that other factors will destroy the pack long before fast charging makes a difference.

[Raptorapture]

Anybody found leaving packs fully charged causing puffing?

[DominicD]

Originally Posted by Raptorapture

Anybody found leaving packs fully charged causing puffing?

One of the many reasons you don't leave packs fully charged, ever.

[acidla]

I fly my packs down to 20% of their capacity. I storage charge them at 60%.

If I am going to fly again the next day, then I fully charge them.

[jmackey]

I have alarms set in my Jeti transmitter for around 50% and 70% consumed mah. When I have consumed 50% of the pack in flight, the transmitter announces "now at storage charge". This is when I land for the last flight of each pack for the day.

No need to hook up to the charger after last flights this way and my lipo's are stored right where I want them.

[Trexwilly]

I storage charge if they are going to sit for a week or more, otherwise I just try and fly them to no lower than 3.75

I charge at 2C, seems like crazy high C only gets you to the balance stage a little quicker, but 1/3 of the charge time is CV anyway, and is more dictated by how good your charger is at balancing the pack, than how much current you throw at it during the CC stage...

[acidla]

Originally Posted by Luvmyhelis

Bottom line, the storage charge saves me time before the outing. And takes time when I have it earlier.

+1!!

[aschen]

Originally Posted by Raptorapture

Anybody found leaving packs fully charged causing puffing?

Im sure everybody is right about it being less than Ideal

However, like I said, I leave all my batts full charged and I have almost no instances of puffing.

I am talking mostly about smaller batteries lots of blade and 450 sized heli packs, but most of them havent puffed up. Some have be stored charged cumulatively for YEARS

[Raptorapture]

Originally Posted by DominicD

One of the many reasons you don't leave packs fully charged, ever.

Unfortunately, I don't have the time necessary to charge just before every flight nor to discharge when I don't fly.

Originally Posted by aschen

Im sure everybody is right about it being less than Ideal

However, like I said, I leave all my batts full charged and I have almost no instances of puffing.

I am talking mostly about smaller batteries lots of blade and 450 sized heli packs, but most of them havent puffed up. Some have be stored charged cumulatively for YEARS

Same for me when I don't fly after charging otherwise usually around 30-40%.

I've never experienced puffing on my 6S's and only recently have I experienced puffing on my 7S's. They almost all got hit at the same time and I've had them over a year, the 6S's over 2 years. I'm trying to figure out the source of puffing. Possibilities are: 1. Recently first time to discharge via charger to storage, 2. Flying them on a high powered motor/low resistance wind, 3. Minor crashes with no visible lipo damage, 4. Stress from resistance during removal of packs due to velcro force being too strong.