waste of time. don't bother.

[The Mighty Volt]

Yep...not budging until Chuck "LFP" Yeager has touched down safely.

 

[SniperGaulois]

Looks like lithium does pretty well in negative temperatures. My question is how much damage will result from charging a pack when it is at -20C/-30C outside(if any).

ALERT ALERT. HUMAN THIS IS PROHIBITED. - Makes buzzing and siren sounds... I asked the same question in a dedicated thread and no one that knew the answer noticed it. my battery got shafted. at lower than 10 degrees, chances are that the chemistry only accepts max voltage of 4.15 and your bms charges to 4.2... at 0 degrees your bms may be overcharging by .1 volts... it depends how good the bms is how much margin it has for cold weather... but i plugged my ping v2 cells assembled half price by a dude, from ebay, and they were fine in normal temps and when it hit zero a couple of times, they reduced by 20 percent and have since dwindled to 50 percent of their original capacity. i havent checked for blown cells and voltage *good idea* but i think that the overall voltage of all the cells is showing a cobined 50 percent discharge curve it aint just a cell. also if have a super fast charger definately just use it in room temps.

lower than 10 degrees may overvolt your cells!!


other than that, lithium is not a water based chemistry so that it is independant of water freezing temps, but it still scales chemically relative to temps.

>>> your battery looks like a bird nest of wires? mine looks like medusa's hairstyle.

 

[Andje]

i can't wait, thank you so much ns for taking the figurative plunge for all of us.

can I ask, how did they agree to ship them to you? because two weeks seems awfully fast for anything but air shipping, and i'm just very surprised they are shipping batts that large under the current scare. For instance, i can't get hobbyking to ship to canada in anything larger then 3.5ah amounts. They wont ground ship from their us warehouses at all. I'm just interested in how they are shipping to you because it might have pertinence on how they would ship to CA. I confirmed with them that they would ship here, but hadn't gone so far as to figure out how/cost.

 

[liveforphysics]

i can't wait, thank you so much ns for taking the figurative plunge for all of us.

can I ask, how did they agree to ship them to you? because two weeks seems awfully fast for anything but air shipping, and i'm just very surprised they are shipping batts that large under the current scare. For instance, i can't get hobbyking to ship to canada in anything larger then 3.5ah amounts. They wont ground ship from their us warehouses at all. I'm just interested in how they are shipping to you because it might have pertinence on how they would ship to CA. I confirmed with them that they would ship here, but hadn't gone so far as to figure out how/cost.

They charged $131usd for shipping. No idea (or concern) as to the shipping method.

 

[The Mighty Volt]

i can't wait, thank you so much ns for taking the figurative plunge for all of us.

can I ask, how did they agree to ship them to you? because two weeks seems awfully fast for anything but air shipping, and i'm just very surprised they are shipping batts that large under the current scare. For instance, i can't get hobbyking to ship to canada in anything larger then 3.5ah amounts. They wont ground ship from their us warehouses at all. I'm just interested in how they are shipping to you because it might have pertinence on how they would ship to CA. I confirmed with them that they would ship here, but hadn't gone so far as to figure out how/cost.

They charged $131usd for shipping. No idea (or concern) as to the shipping method.

For $131, it had better be good.

That said, $100+ is the 6 weeks "ground" option on 20Ah LiFePo4 batteries from China to Ireland. Usually on a boat. With the BMS attached.

 

[Andje]

131 for ten is still only 13$/battery for shipping at this price. thanks lfp.

 

[Anonymous]

i hope i actually get some of these if they're any good.. b4they sellout in 45mins :lol: :lol:

 

[cord]

Ok so I've got some light to shed on the pricing side of these batteries:

These promotion product price is very low ,because we want to sell out before the Christmas . And we will product the new battery cell next year . but the price will grow up . different price . Because only left 2 months ,is Chinese NEW YEAR . so every company or factory want to sell out they product . Nobody product new more product before the NEW YEAR . But if you want to order the same product , we can do them for you Next Year .

Regards !

yan

And when I inquired about next year's prices:

The price will be 182USD-272USD for one pack 22.2V 20000mah battery .

yan

So there you have it!

 

[neptronix]

And when I inquired about next year's prices:

The price will be 182USD-272USD for one pack 22.2V 20000mah battery .
yan

So there you have it!

That low end price is just about where 4x 6s 5000mAh zippy packs costs.
Even at $250 USD, i think it would be a good deal just because of all the eliminated hassle.

Boy would i love to have a 10s pack made up of these, rather than 8 zippy packs + a rat's nest of wiring.
Just imagining how it would fit in the frame triangle right now... aww yeah 8)

 

[cord]

Boy would i love to have a 10s pack made up of these, rather than 8 zippy packs + a rat's nest of wiring.
Just imagining how it would fit in the frame triangle right now... aww yeah 8)

Order up two of these:

http://hobbyrcworld.en.alibaba.com/product/361391030-209613140/20000mah_18_5V_20C_RC_Lipo_Battery_For_Big_Airplane_RC_Battery.html

 

[neptronix]

Order up two of these:

http://hobbyrcworld.en.alibaba.com/product/361391030-209613140/20000mah_18_5V_20C_RC_Lipo_Battery_For_Big_Airplane_RC_Battery.html

VERY TEMPTING.
However i cannot find any real information on this company.

They have a broken website, and an expired business license ( according to alibaba ):
http://hobbyrcworld.en.alibaba.com/trustpass_profile.html

That is a smokin' deal ( about half the cost of zippy/turnigy ), but i will wait to see what happens with LFP's packs..

 

[AussieJester]

Who says we aren't doing that? My low voltage alarm is at 3.5, and I generally charge from 4.0 to 4.1 depending on my mood and range I need.


That is a discharge graph though, not a charge input vs capacity graph.

Exactly...theres been people using Lipo on this forum for a couple of years now
all of a sudden people think its something new what's with that?

anywayz yup same John i never charge above 4.15 and the lowest i ever seen on my pack are 3.5v a cell on my 44v 20ah lipo pack

I have also emailed this company asking for price and cost of frieght charges for 4 of these to checkz out, i need to know
the physical size if anyone has stumbled on it if its here i missed it just scanned through the entire thread, if they don't fit the area
planned for lipo ib my new bike i will have to pass and go with Turnigys again ...I hope they turn out to be what they say they are or near to it, 10-15c
would do fine for me, 4 packs 44v 40ah yeah haaa...

KiM

 

[solracotos]

Order up two of these:

http://hobbyrcworld.en.alibaba.com/product/361391030-209613140/20000mah_18_5V_20C_RC_Lipo_Battery_For_Big_Airplane_RC_Battery.html

VERY TEMPTING.
However i cannot find any real information on this company.

They have a broken website, and an expired business license ( according to alibaba ):
http://hobbyrcworld.en.alibaba.com/trustpass_profile.html

That is a smokin' deal ( about half the cost of zippy/turnigy ), but i will wait to see what happens with LFP's packs..

I have to admit that it is temping too. I sent email for quote. I may take the plunge! My other option is hobby king... But then I will end up with 4 batteries to make my pack.

After I get response from my email I will post response.

 

[AussieJester]

I just received a reply to my enquirers and received a December promotions catalog

KiM

 

[olaf-lampe]

I just received a reply to my enquirers and received a December promotions catalog

KiM

Hmmm,
makes me wonder, why the 20Ah battery is so much lighter than the rest.
The 6s/10Ah batt weights 1500 gramm and the 6s/20Ah only 2200gramm. :?
Could it be, they are the old LiCo-type of cells? They'd have a higher energy density, but they tend to catch fire at a puncture test.
I guess Luke will show us a video of that sooner or later
-Olaf

 

[johnrobholmes]

It could also be a lower discharge rate, less metal inside them.

 

[vanilla ice]

They are higher Cmax than the 10ah pack, the opposite of what you would expect if they were the same chemistry.

 

[Jeremy Harris]

Looking around it does seem that the rough energy density of most RC LiPo packs is around 140 to 150Wh per kg. For comparison, here are some typical energy densities I've measured from my own packs:

Turnigy 3S 5000mAh = 138Wh/kg
Zippy 4S 5000mAh = 146Wh/kg
Zippy 5S 5000mAh = 147Wh/kg

The 6S 10Ah packs on that site come out at 148Wh/kg, pretty much what I'd expect based on the above data.

As has been said before it does make me wonder quite how the 20Ah packs manage to come in at over 200Wh per kg.

Jeremy

 

[solracotos]

Ithink these batteries are almost worth the money at 500-600 cycles. If it solves the 'rat's nest' problem of 50 positive and negative cables rewiring, I'd rather lose 200-300cycles out of a standard lipo and gain 'plug and play', this decreases the chances of something going wrong (plasmaball) dramatically for any n00b

cool hope its not a total piece of excrement. Think I might convert my old 450 nighthawk with decent batteries at those prices 8)

Hey novembersierra what makes you say that those lipos may only give 500-600 cycles? Aren't lipos capable of 1000+ cycles for most low key e-bike applications? Like low charge and discharge rates, making sure the voltage limits are not exceeded etc.

 

[texaspyro]

As has been said before it does make me wonder quite how the 20Ah packs manage to come in at over 200Wh per kg.

Easy, suitable application of the binary feed forward specification fudger... If it looks to good to be true, it is.

 

[Anonymous]

read the thread Yan states that she thinks these batteries have 150 charge cycles. I think that would be problematic. so charging them at 4.1v / 80% would probably raise that significantly to 500-600 cycles.
Also, charging tests, practical tests, indicate that even standard lipos that are charged to their 4.2v limit suffer at 600 charge cycles and lose their capacity. (source: watching members on here use lipo and report their experiences)

Hey novembersierra what makes you say that those lipos may only give 500-600 cycles? Aren't lipos capable of 1000+ cycles for most low key e-bike applications? Like low charge and discharge rates, making sure the voltage limits are not exceeded etc.

 

[solracotos]

read the thread Yan states that she thinks these batteries have 150 charge cycles. I think that would be problematic. so charging them at 4.1v / 80% would probably raise that significantly to 500-600 cycles.
Also, charging tests, practical tests, indicate that even standard lipos that are charged to their 4.2v limit suffer at 600 charge cycles and lose their capacity. (source: watching members on here use lipo and report their experiences)

I see, While reading I didn't not find the entry where "Yan states that she thinks these batteries have 150 charge cycles".

I'm upgrading from 36v 12ah SLA batteries. I have put close to 600 miles on them. Range went from 13.5 when new to about 7.5 in the first 3 months before the LVC kicked in (~31.5v). Now, a year after with about 250 cycles, I'm lucky to get 5 by babying the trottle. I want to get a battery system that modular and that will have more than 500 cycles, giving me at least two years of use. In that case I think I might go with 18.5 v 5Ah lipos to make 36v packs of 5-15 Ah.

Between of these two, which one would you choose?
http://www.hobbypartz.com/83p-5000mah-5s1p-185-25c.html
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14844

Both of them same price, HK charges about 25 for shipping these. Hobbypartz is free.



PS:

I just received a reply to my enquirers and received a December promotions catalog

KiM

I got a quote for batteries too. , View attachment PI-ECY-101209058(3).xls; View attachment PI-ECY-101209058(4).xls
With no answer to my questions yet.

The price is ~20 dollars lower than the one on the thread title.

 

[x88x]

I've never heard of the hobbypartz (not surprised, I'm pretty new to this myself), but fwiw I've found that if I leave the hobbyking window sitting for a while it'll usually offer me a small discount (usually ~3-4%).

 

[Anonymous]

I'd say wait till LFP mentions something about his tests.

Just as a word of warning, I emailed Yan today, asking her to 'reserve' 6 batteries for me, she didn't reply, .... I don't like that at all and think it's fishy, almost suggesting as if she's hauling batteries to users before we find out there's something bad with them.

don't buy until we find out if these are okay to use, and then if the 20ah's are good for even 60A... that's good enough for most users on this forum + a dumb balance charger (b4) by imax permanently wired into the pack.... that oughtta do it. also, that bms / lvc fender apron sounds like a must.

let's find out what happens

I got a quote for batteries too. , View attachment 1;
With no answer to my questions yet.

The price is ~20 dollars lower than the one on the thread title.

 

[AussieJester]

read the thread Yan states that she thinks these batteries have 150 charge cycles. I think that would be problematic. so charging them at 4.1v / 80% would probably raise that significantly to 500-600 cycles.

If we look at Liveforphysics post->

This seems to be something people always tend to get wrong, but C-rate during discharge has a pretty minor effect on the life cycles of a pack. Stronger effect on pack lifecycles from high C-rate charging, and HUGE effects on a pack's life for low-temperature charging.
The big life-cycle extender is in the DOD, which you always want to take out of the middle of the pack, not just leaving some in the bottom.
A pack that might have 100cycles of 4.25v to 3.2v can easily have 500cycles of 4.15v to 3.5v, and thousands of cycles from say 4v to 3.6v.
Just keeping C-rate low has a comparatively minimal effect on cycle life compared with keeping the DOD in a shallow range.
If you wanted a useful 20Ah pack from these for thousands of cycles, buy two, parallel them, and charge them to say 85% full, and discharge to 35% full. You only use 50% of the available capacity this way, but your pack lasts thousands of cycles, and if you ever have a trip where you need all the range you can get, just charge it all the way up and discharge it as low as you need. It might do the same damage of 50-shallow cycles, but at least you've got the option available if needed.

This leads me to believe if we build higher ah packs and don't discharge past 80% we will be taking the majority of the charge out of the middle of the packs UNLIKE when used
in RC modes, the charge cycles given by manufacturers are likely based on the their use in model applications, where only ONE or TWO packs at most are used, they are totally emptied in ~6-8minutes in a flight, this IMO differs ALOT too how we ue them in an ebike applications. We are using using multiple packs and if we don't charge above 4.15v or discharging below 80% I think we could safely expect charge cycles to be into the 1000's

Also, charging tests, practical tests, indicate that even standard lipos that are charged to their 4.2v limit suffer at 600 charge cycles and lose their capacity. (source: watching members

Who here has stated they have only gotten 600 cycles using the modern lipos such as the popular Turnigy or Zippy Lipo packs? I haven't seen any usesrs of these packs state they have done this, have seen one or two using 3-4 year old non name brand lipos state they have had low charge cycles, my apologies if i am wrong and feel free to correct me if i am? (link) to anyone thats had only 600 charges from Turnigy or Zippy packs when used in ebike application using multiple packs in series and parallel.

KiM