Flight Power lipos - 20C cont?

[suxbux]

Was going thru' the Wattflyer website and came across this thread http://www.wattflyer.com/forums/show...t=1110&page=11.

Says that the claimed 20C continuous by FP will cause permanent damage to the batt. and reduced capacity with every cycle and even at 15C things do not look good.Excessive temps were recorded. It also shows the same voltage dip at start of discharge as the PQ cells and later on, FP admits that its lipos are actually from Enerland and cells are the same as the Polyquest and Hyperion cells.

A lot of mud slinging between the testers and FP over the claims with FP requesting the thread be closed! Apparently at discharge rates above 10C, cycle life drops a lot to about 20 to 50 charge cycles.

I'm still on the lookout for replacement cells- KP do you have any comments on this thread and any assurances? thanks

[Frank]

Looks like you need emolis

[suxbux]

Hey Frank, where to get those cells? Sounds good at 15C discharge and 3C charge.Is that right? and how do they perform?

[Frank]

You will have to get them off ebay.
So far so good.

[Unorthodox_Sniper]

Hi Suxbux,

Yes I saw that thread last year, btw technology has progressed since then with the introduction of EVO20 NF (for higher capacity packs) that runs even cooler and slimmer 2105mAh packs. But let's not deviate from your question

I'm sure you will notice there are numerous threads in the Internet on the major RC Lipo players such as TP & Etech about their claims on high discharge rate. As with all RC Lipo, thermal heat is the biggest killer on lipo lifespan and there is no denying that even for the best high-end RC Lipo their life span is about 50 cycles at 80% capacity if you constantly + continuously push it to its rated limit.

Unlike some brands of high-end Lipo that does not give any info, FlightPower displays these info upfront on their website and they never deny that 20C continuously discharge at 1C charging gives a lifespan of 50 cycles of 80% capacity.

But the crux here is we ask ourselves how hard do we always push our packs? Do we always push it to max rating continuously by flying full throttle constantly all the way with no air cooling and no throttle control?

For me personally before I'm the distributor for FlightPower, I always purchase highest-rating lipo but I don't push them to their current limit continuously & my packs come down warm & not hot to the touch so that I enjoy longer flight duration & longer lifespan. So if eg I buy a 1800-3S 15C branded lipo and a 1800-3S 20C FlightPower Lipo and I fly my planes at the same current drain, FlightPower Lipo will give more punch because it is able to maintain the voltage much better and it also runs cooler = longer lifespan.



For everyone's convenience I have extracted info from flightpower's tech website http://www.flightpower.co.uk/acatalog/battery_data.html
Some of the graph are Courtesy of Christain Samuels - Team Mikado and while they maybe sponsored by FlightPower I doubt they will want to ruin their reputation to give false info



Discharge Performance. Pictured above is the Enerland discharge curve for the this cell type created using an Arbin Instruments industrial battery tester. The practical outcome is extremely high voltage held under load which means that when more Amps are drawn at high throttle more Watts are delivered (instead of the volts dropping away). Amps x Volts = power in Watts. The FlightPower EVO 20 manufacturing proces has been designed with the RC user in mind to ensure that packs created from multiple cells are able to hit the target of multiples of the voltage performance seen here. Accurate cell matching during manufacture and low resistance joints are the key to achieving this and verification has taken the form of high-discharge load tests using brushless motor loads as well as numerous independent flight tests by world-famous pilots and the testing houses of large distributors, all of which have confirming that the EVO 20 product is a performance leader in a class of its own.
In common with other reputable makes of RC battery, the continuous C-rating of "20 C" applied to the EVO 20 line is a measure of the maximum continuous current drawn before the pack will suffer excessive wear, however depending on the brand, the definition of excessive wear can be unlear and can range from immediate damage to a number of cycles. In the case of FlightPower EVO 20 we estimate 50 charge and discharge cycles using a 20C motor and prop/EDF load undar a 1 C charging regeime and have satisfied ourselves in testing that we can exceed this in real life. The vast majority of RC applications use a great variety of throttle demands during discharge therefore the purpose of selecting a 20C EVO 20 battery pack is to ensure an exciting throttle response is available upon demand.



In use: The graph above (Courtesy of Christain Samuels - Team Mikado) shows the discharge profile of a FlightPower EVO 20 3300mAh 10s1p pack in use in a Mikado Logo 14 V-Bar helicopter during extreme 3D. The pack is holding an average 3.61 V per cell at a median of 10C (outperforming the Volts per cell above in a 10s configuration) with numerous calls for 20C (66 Amps) and peaks approaching 30C balanced by numerous off-throttle calls. The peak demand in Watts is 3019 (4.05 Horsepower) outclassing the best of alternative brands in the same series of tests by 10% with a weight saving of 14% over the same. At the end of this flight the battery had delivered 3419 mAh against a rated capacity of 3300mAh and had reached a temperature of 40 Degrees C indicating very little thermal stress and therefore a prognosis of high reliability in this application. In live tests such as this, the FlightPower EVO 20 battery type achieves the higest voltage under load and the highest retained capacity available in an RC battery.
The example here shows extreme 3D performance using a large battery delivering power beyond the capability of most RC pilots to control. Across the FlightPower EVO 20 range, the benefits of exciting verticals, big loops and high reliability are available to all.
In summary, the FlightPower EVO 20 battery type is particularly well suited to RC applications!



Thermal performance: Shown above is the temperature reached at 20C constant in an ambient temperature of 23 degrees C. This is the limit of the rated performance. For normal applications and for good cycle life it is recommended that the temperature be constrained to a maximum of 50 Degrees Centigrade at the end of a flight.
This is done by selecting motor and propeller combinations that normally draw less currnet than the limit of the rated performance. By definition a 1C discharge will deplete the full capacity of the pack in one hour. 20C therefore will deplete the pack in 1/20th of an hour or 3 Minutes (2.5 minutes in all practicality). Because it is nearly always desirable to carry a battery pack of sufficent capacity to fly the model for longer than 2.5 minutes, normally for 6 minutes for absolutely extreme performance (10C average with high peaks and troughs as in the above example) and very often for 10 minutes or more outside of the competition environment. For this reason, the FlightPower EVO 20 battery line is famous for arriving cool after delivering a very exciting performances. The other notable feature is that very often each cell in the pack will remain matched by voltage +/- 0.001 Volts after many successive flights. This is owing to the matching during manufacture. Over many 10s of cycles this can be maintained with the use of a cell balancer.



Cycle life: Shown above is the cyclic performance at 20C showing the reduction in voltage-under-load performance and capacity over 50 cycles. This is the limit of rated performance.
As a guideline:

1 C Charge 20C average Discharge, cycle life expectayion: 50 Cycles to 80% Capacity.
This will only affect the craziest EDF projects and must be factored in as the normal running cost of such applications.

1C Charge 10C average Discharge, cycle life expectation: 200 Cycles to 80% Capacity.
This represents the limit of normal RC use and most users should regard 200 Cycles as a minimum expectation to 80% retained capacity, of course the pack will normally continue to function well beyond this point.

2.5C Charge 10C Discharge, cycle life expectation: 100 Cycles to 80% Capacity.
Fast charging at 2.5C is possible with the FlightPower EVO 20 packs in exchange for a reduction in cycle life. This is recommended "in case of need" and use of a balancer is advised.

[suxbux]

Thanks KP for the headsup.I'm still at a loss to surmise if these cells are heads over shoulders with the rest as they are not the exclusive manufacturer and the cells are available to polyquest,hyperion and other sellers.
Therefore performance can't be better than the others, am I right?
I'm using Etecs running at 10C and they're pretty durable.What I'm looking for is something that can last as long as the etecs and provide better performance and doesn't cost a bomb.The polyquests that I've owned were appalingly poor performers and with that big dip at startup.
I don't own or have seen the FP so I am in no position to comment but the relationship between PQ and FP ( same cells)worries me.
I'm sorry for questioning the product before trying.I guess maybe enerland has improved their product.

[Unorthodox_Sniper]

Hi Suxbux,

No worries about your doubts. There is no doubt that Korea is the world leader in Lipo and there are only a very few handful of reputable lipo manufacturers in Korea. Do some indepth research and you will know the top rc lipo players all get their raw cells from the same source

During lipo manufacturing process there will always be different grades of raw cells. And all the cells in a pack must be perfectly matched in order for the pack to give you that punch and longevity because it just takes one cell in a pack to be "weaker" than the others and the whole pack will show signs of failure and short lifespan soon.

I can't answer what grades of raw cells does other brands get but Flightpower gets the best grades of raw cells and uses the strictest possible lipo manufacturing process. More info is available at http://www.flightpower.co.uk/core/FP...ufacturing.htm
and they have a customer first policy.

Since I know you personally if you don't mind I can pass you a brand new pack of 1800-3S or 2150-3S to try for free. You can return me without paying if you are not satisfied with it or you can pay for it if you are satisfied

[DT8666]

Hi Suxbux,

No worries about your doubts. There is no doubt that Korea is the world leader in Lipo and there are only a very few handful of reputable lipo manufacturers in Korea. Do some indepth research and you will know where TP and Etech raw cells come from

During lipo manufacturing process there will always be different grades of raw cells. And all the cells in a pack must be perfectly matched in order for the pack to give you that punch and longevity because it just takes one cell in a pack to be "weaker" than the others and the whole pack will show signs of failure and short lifespan soon.

I can't answer what grades of raw cells does other brands get but Flightpower gets the best grades of raw cells and uses the strictest possible lipo manufacturing process. More info is available at http://www.flightpower.co.uk/core/FP...ufacturing.htm
and they have a customer first policy.

Since I know you personally if you want I can pass you a brand new pack of 1800-3S or 2150-3S to try for free. You can return me without paying if you are not satisfied with it or you can pay for it if you are satisfied

Hi, I got 2 2100 3S EVO, to my diappointment that at the 5th cycle charge with Tahmazo TL4 at 2000ma, the pack is blotted and gas filled in Cell 1 and Cell 3. After I release the gas using a pin, now Cell 3 shows auto discharge in one day by about 0.09V. Now my hold pack is unballanced.

Why such thing can happen?

I have seen both pack running on my F16 shows relatively hot and shows some gas built up after flight. The setup only draw at full ower 29A, this should be well within the spec. Howver, that pack is back to normal shape when cooled down until one of the pack show the above problem. is this normal?

[Mazon]

hi

it may be cos u are using Tahmazo TL4. ADVISORY at http://www.aircraft-world.com/ says
"Posted Nov 2005: A "balance" charger made in Taiwan and marketed under several names - Tamazo, enLipo en-CRG4, NOVATECH B8080, and possibily others - will overcharge lithium packs. (termination voltage per cell as high as 4.32V). Use of these chargers will void any warranty claims.
A pack which shows ALL cells "puffed" is certainly victim to over-volt charging, and will not be replaced under warranty.
Apparently these are appearing under more brands, such as TopModel X-Power. If your charger mentions "parallel" charging and has multiple ports, it should not be used with the lithium batteries we sell, unless you confirm by testing yourself that voltage does not exceed 4.275 per cell (and 4.25 max would be even better)... "


they are refering to the same model as tamazo TL4. someone mentioned this awhile ago http://www.daddyhobby.com/forum/show...light=advisory

Hi, I got 2 2100 3S EVO, to my diappointment that at the 5th cycle charge with Tahmazo TL4 at 2000ma, the pack is blotted and gas filled in Cell 1 and Cell 3. After I release the gas using a pin, now Cell 3 shows auto discharge in one day by about 0.09V. Now my hold pack is unballanced.

Why such thing can happen?

I have seen both pack running on my F16 shows relatively hot and shows some gas built up after flight. The setup only draw at full ower 29A, this should be well within the spec. Howver, that pack is back to normal shape when cooled down until one of the pack show the above problem. is this normal?

[DT8666]

hi

it may be cos u are using Tahmazo TL4. ADVISORY at http://www.aircraft-world.com/ says
"Posted Nov 2005: A "balance" charger made in Taiwan and marketed under several names - Tamazo, enLipo en-CRG4, NOVATECH B8080, and possibily others - will overcharge lithium packs. (termination voltage per cell as high as 4.32V). Use of these chargers will void any warranty claims.
A pack which shows ALL cells "puffed" is certainly victim to over-volt charging, and will not be replaced under warranty.
Apparently these are appearing under more brands, such as TopModel X-Power. If your charger mentions "parallel" charging and has multiple ports, it should not be used with the lithium batteries we sell, unless you confirm by testing yourself that voltage does not exceed 4.275 per cell (and 4.25 max would be even better)... "

they are refering to the same model as tamazo TL4. someone mentioned this awhile ago http://www.daddyhobby.com/forum/show...light=advisory

I saw that post before and doing certain test before I continue to use. My set terminate at 4.23 so it is still within the safe range.

This charger already work on my Etec, TP and War-bird lipo without any issue. I don't think that is the main issue.

[Unorthodox_Sniper]

I saw that post before and doing certain test before I continue to use. My set terminate at 4.23 so it is still within the safe range.

This charger already work on my Etec, TP and War-bird lipo without any issue. I don't think that is the main issue.

Hi DT8666,

When your cell terminates at 4.23v, it is not the maximum absolute voltage ie the max voltage that passes thru the cell is not 4.23v. This is because during charging when very near to peak the max voltage is always higher and can be as high as 0.5v so if after charging and the cell maintains at 4.23v it is likely the cell has experienced a max voltage of 4.28v and this is bad for lipo. If you refer to the label on flightpower they warn against a maximum absolute of 4.25v which means during charging the maximum allowed voltage must not exceed 4.25v.

From flightpower and my own personal experience, very high-discharge lipo are more sensitive to over-charging as compared to lower discharge lipo.

Tahmazo TL4 is indeed a problematic charger and I'm sure everyone agrees that aircraft-world is top notch in customer service and they give very good sound technical advise.

For your benefit of doubt, please PM me and I will arrange to swop to brand new flightpower packs to replace your bloated ones. But I must advise you to get another lipo charger and a good balancer (flightpower will be coming up with a brand new active balancer in mid June at an attractive price). You need not purchase an expensive lipo charger, I personally have the Prolux lipo charger which costs about S$50 and it works flawlessly. However if you continue to use Tahmazo TL4 and bloats the swopped new flightpower packs I will not be able to replace for you again.

If you do not believe in us that the Tahmazo TL4 is flawed and you prefer not to use Flightpower, I will gladly refund you the money

[DT8666]

Hi DT8666,

When your cell terminates at 4.23v, it is not the maximum absolute voltage ie the max voltage that passes thru the cell is not 4.23v. This is because during charging when very near to peak the max voltage is always higher and can be as high as 0.5v so if after charging and the cell maintains at 4.23v it is likely the cell has experienced a max voltage of 4.28v and this is bad for lipo. If you refer to the label on flightpower they warn against a maximum absolute of 4.25v which means during charging the maximum allowed voltage must not exceed 4.25v.

From flightpower and my own personal experience, very high-discharge lipo are more sensitive to over-charging as compared to lower discharge lipo.

Tahmazo TL4 is indeed a problematic charger and I'm sure everyone agrees that aircraft-world is top notch in customer service and they give very good sound technical advise.

For your benefit of doubt, please PM me and I will arrange to swop to brand new flightpower packs to replace your bloated ones. But I must advise you to get another lipo charger and a good balancer (flightpower will be coming up with a brand new active balancer in mid June at an attractive price). You need not purchase an expensive lipo charger, I personally have the Prolux lipo charger which costs about S$50 and it works flawlessly. However if you continue to use Tahmazo TL4 and bloats the swopped new flightpower packs I will not be able to replace for you again.

If you do not believe in us that the Tahmazo TL4 is flawed and you prefer not to use Flightpower, I will gladly refund you the money

Cool service. I will PM you the detail and stop using TL4 on EVO. BTW, I mostly using ISL330 and now moving to use offline balance with TP205.

Thanks for the quick reply and great customer service.

Cheers!

[Kam]

Read the thread and came to the conclusion that FP is an above average lipo pack, just that they "over hype" it. I'm using FP now and have no problems with them. They are at a good price as well.

However, I'm not quite sure what all the hype is about TP though. Comparing the specs and price diff, it is obvious that FP is the choice but many ppl still swear by TP. I posted this question on helifreak but got no answers as well. Any opinions here?

Thanks KP for the headsup.I'm still at a loss to surmise if these cells are heads over shoulders with the rest as they are not the exclusive manufacturer and the cells are available to polyquest,hyperion and other sellers.
Therefore performance can't be better than the others, am I right?
I'm using Etecs running at 10C and they're pretty durable.What I'm looking for is something that can last as long as the etecs and provide better performance and doesn't cost a bomb.The polyquests that I've owned were appalingly poor performers and with that big dip at startup.
I don't own or have seen the FP so I am in no position to comment but the relationship between PQ and FP ( same cells)worries me.
I'm sorry for questioning the product before trying.I guess maybe enerland has improved their product.

[YZY]

TP capacity to weight ratio is way higher then FPs like the 2100s vs the 1800s which weigh almost the same but 300mah less

[Kam]

Yup but weight diff between the TP2100 and FP1800 is only 7 grams. Anyway, I tried a friends TP today and there was a significant diff. Just not sure if that amount of power justify the extra $.