LiPo Charge Cycles, how many is "broken in"

[LI-ghtcycle]

I am just curious how many charge cycles it generally takes for LiPo batteries to settle down and balance quicker?

From reading part of a post about someone else's build, it would seem there is a bit of a break-in period, and mine are still quite new, about 30 cycles on my core pack (six 4s Nano Tech 25 - 50C 6AH packs wired for 12s 2p, making 47V at 12 AH) and I have just added two new 6S 25 - 50C 6AH Nano that now have about 5 cycles on them.

I have a Hyperion, and I'm a bit of a perfectionist, so I love to get them as perfectly balanced as I can (as I have time, otherwise as long as it's under 0.1 across the 8s or 12s group, I don't sweat it) and typically the packs stay with-in 0.05 or closer.

Maybe I am just splitting hairs, I'm still kinda new to LiPo (I had to take about a 3 month break due to ill health, and then no E-Bike for another 2-3 months) so even though I have had the original pack since Dec 2010, (at least in the current configuration, I had used some earlier with the friction drive, so maybe some packs have closer to 50 - 60 cycles.. ok I'm feeling old now ... lol! good thing I kept a log at least after I started using 12s 2p ) I have only been using them for the better part of 6 months.

I guess what I am asking is, what is the break-in period for the average pack? From my reading it would seem that some people believe you need to cycle the packs gently at least a few times (which I have done) before putting them into normal use, and now that I have a 12s 18AH pack, I'm thinking short trips using around 2 - 6 AH's is more than gentle enough for the new cells, but will I notice an significant time reduction balance charging say, once they have 10 - 20 cycles on the new ones?

So far I have noticed that the deeper discharges (6 - 8 AH's) seem to balance much quicker than very shallow (2 - 3 AH's) ones, maybe it's because I need to "stretch their legs" and give them a work-out?

I have even braved 35 - 40F temperatures with out any increased voltage sag what so ever!

Again, I know I am probably just being overly cautious and concerned, but it's what I do .... it's a family trait (curse! :lol: )

 

[neptronix]

0 cycles is broken in

A lipo pack with good cells, balanced with a well-calibrated charger will stay within good balance for a hundred cycles or more.

 

[LI-ghtcycle]

0 cycles is broken in

A lipo pack with good cells, balanced with a well-calibrated charger will stay within good balance for a hundred cycles or more.

Define "balanced"

I have my trusty Hyperion with "Hyper Microscopic Anal Vision!" (TM) and can observe the balance with in 0.0001 volts!

Don't under-estimate my ability to geek-out on the details! :lol:

 

[neptronix]

10mV or less fully charged to 4.2v/cell.

( a lot of voltage reading devices that don't cost $$$ can't read more accurate than that anyway. )

 

[LI-ghtcycle]

10mV or less fully charged to 4.2v/cell.

( a lot of voltage reading devices that don't cost $$$ can't read more accurate than that anyway. )

Ahh, so you're saying it should be with-in 0.001 V as tolerance? I know that's nothing spectacular, I'm just laughing at myself for being so silly about making it so precise ... I'm just "punch drunk" from lack of sleep really. :lol:

Yeah, I'm just tired, the stupid dog woke everyone up at 4 AM and I am just really starting to feel the lack of sleep! Might be a good time to go for an E-Bike ride!

After all, it's "warmed up" to a whole 51F! I think the cold is starting to get to my brain too, last night it was in the high 30's to low 40's and with wind, I had to wear 3 layers and still felt it!

Still isn't taking off my E-Bike grin though!

However, I think Monday's ride to Portland and back was a bit of a mistake, the cold really zapped my strength, and E-Bike or not, hard to balance when you have VERY little strength, and had to walk up the steep hill, (about 1 mile) because I was just too tired to balance well. :wink:

Time for a trike!

 

[liveforphysics]

I've noticed they tend to increase in capacity for about the first 20 cycles or so. They also decrease in resistance a bit.

This is what I call "break-in".

 

[LI-ghtcycle]

I've noticed they tend to increase in capacity for about the first 20 cycles or so. They also decrease in resistance a bit.

This is what I call "break-in".

Kewl, I'm not totally loosing my mind then, was beginning to think the "break in" was myth, I have noticed the balance times vary according to the DOD, but that's just "butt dyno" stuff, not even gonna call it an "educated guess" on my part!

Still never regretted going LiPo, I was freezing the last two day's riding in the evening, but the batteries never seem to care, I do have them pretty well insulated inside a soft lunch "box" and all the other junk I carry near it (clothes, gloves, tools, I know I'm a pack-rat! ) but maybe it just hasn't been cold enough to matter yet.

 

[liveforphysics]

If you are running Nano-Tech cells, you're likely never going to see noticeable voltage sag no matter what temp or what load you manage to put on them. They do perform worse at low temps, but they still perform so darn well, you hardly notice.

 

[dogman dan]

I don't scrutinize my batts as much as some. I found 85% of the lipo I've bought was "broken in" right out of the box. But the way I know it is or isn't is revealed on one cycle. 10% were just bad from the get go, arrived puffed, or puffed by cycle ten or so. the other 5% needed a handfull of cycles to wake up the lazy cell. Anything that balances good on cycle 1 is good, or at least good till it puffs later if it ends up doing that. In regular use later, I don't bother with any balancing if a pack at top of the charge is out of balance by .05. It's not so important, if I'm practicing an 80% dod max.

In general, if nothing bad develops by cycle 10, you likely can trust em enough to do permanent stuff like paralelling them with solder, or permanently building into a bike.

 

[Holocene]

Hi LI-ghtcycle,

If you have some spare AHrs with your battery pack, have you considered a 12-v electric heated vest? You may need to configure it as a separate battery pack to give the vest what it wants, but it's a wonderful way to stay warm while riding, a true warm-cozy feeling. Especially with a thermostat.

Cheers, and stay warm!
Holocene

 

[DAND214]

You mentioned all the clothes you were carrying.
Don't you think wearing them would help keeping you warm? :lol:

I carry extra gloves and hood when it's cold. Almost had to use them last week. I don't like it out there when it's below 40f and I still ride when freezing.

It's gotta be the LIPO that's affecting me.

Dan