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marter1229
09-09-2005, 12:44 AM
I have been reading this forum quite a bit, and I can't recall anything about times. I know that different packs will require different times, but can someone give me a ballpark figure, or a rule of thumb.

Do you get one flite a day from a 3c 750 pack, or can you field charge them in 30 minutes, or 2 hours? {example}

Thanks
Terry

fdix
09-09-2005, 02:04 AM
You always charge with 1C (for example a 1500mAh pack with 1,5A). When the charger recognizes the pack has hit 4,2V/cell it will gradually lower the charge current until it arrives at 0 amps, then the pack is full.

Charging takes about one and a half hours. But after using your LiPo you should let it rest for six hours before recharging it, this is what manufacturers recommend.
You can recharge it after a shorter period of time of course, it will only shorten the battery’s lifespan a bit.

flypaper 2
09-09-2005, 04:09 AM
I find they take around 1 hr. to 1 1/4 hrs to charge, take them out and use them, then back on the charger.

Matt Kirsch
09-09-2005, 06:03 PM
I've never seen any reference to a six-hour resting period between charges. What manufacturer recommends this? Can you provide a link to the documentation that shows this recommendation?

Otherwise, everybody is pretty much correct. It takes between 45 minutes and 1-1/2 hours to charge a LiPoly at the recommended 1C charge rate, depending on how discharged it is. An empty pack will take closer to 1.5 hours, while a half-empty pack will take closer to 45 minutes. Ideally, the 1C charge rate would charge an empty pack in exactly 1 hour, but nothing is ever 100% efficient, and the characteristics of LiPoly batteries require the charge rate to taper down slowly as the battery fills up.

fdix
09-09-2005, 06:33 PM
My dealer told me. I'll ask him ;)

Anyway the loss in lifespan is only marginal if you simply let the pack cool and then put it on the charger again.
But if you fly a 500$ pack you might want to keep it in the best possible shape...

GeraldRosebery
09-09-2005, 11:20 PM
I have been reading this forum quite a bit, and I can't recall anything about times. I know that different packs will require different times, but can someone give me a ballpark figure, or a rule of thumb.

Do you get one flite a day from a 3c 750 pack, or can you field charge them in 30 minutes, or 2 hours? {example}

Thanks
Terry

Actually Terry you ask a good question. The answer, of course, is "it all depends" (Doesn't it always). If you use say, 90% of a pack's capacity you can recharge at 1C to about 90% of capacity in about 1 hour. If you insist on 100% (approx) of capacity it will take about 1 1/2 hours as your charger will drop into constant voltage mode at about 90% of capacity and current drops at the same time. SO - after this bable - you can fly after the 1 hour of charge but flight time with be reduced some. But then, you can always do a "top up" charge at the end of the day.

Rugar
09-09-2005, 11:32 PM
My dealer told me. I'll ask him ;)


Someone needs to change dealers :eek: .

Jatkiss
09-15-2005, 11:37 PM
I am having a hard time with charge times also. It actually took 6 hours to do a full charge of my 700 MLA 3 cell lipo the other day and I figured that I must have had a setting messed up. I had pretty much drained the battery and it is a charger called an Accu Cycle.

It has two charging stations built into it and has a nice digital display. It also autorecognizes the battery (I always check to make sure the settings are correct though).

It runs off AC and then goes through a transformer as I go through the charging process.

Don't want to ruin or damage the batteries. So I thought I would post here and ask the questions.

- Jeff
Newbie Electric Flyer

Steve
09-16-2005, 12:18 AM
To answer the original post...if you charge a 750MAH 3cell Lipo at 1C .75Amps...it should take an hour or so.

To jatkiss...something's not right there. Either you are charging at a very low amperage...like 50 milliamps, your battery is shot, or the charger itself is no good.

I would be careful with that battery.

Can you tell if it's taking a full charge?
Is it warm while it's charging?
Have you over-discharged it by mistake?
What do you mean it "goes through a transformer"?

Jatkiss
09-16-2005, 01:52 AM
It does not get warm at all while charging. It just seems to be charging very slow. I can actually plug the charger into the wall in my house to charge the battery. That is why I am wondering if the charge time is much slower.

Charge current is at .15A and the discharge is at .30A. This may be where my problem lies also...I am REALLY new to this so I just want to make sure I have things set up right.

Just did a hot-glue repair on my you can fly 3d plane if that gives any indication as to how new I am =- ).

- Jeff

ptb
09-16-2005, 03:03 AM
I think your charge current is about 1/5 of what it should be!

Jatkiss
09-16-2005, 03:17 AM
What about discharge ?

So should charge be around .65A and the Discharge stay the same?

- Jeff

ptb
09-16-2005, 03:39 AM
If you have a 700ma pack, you could charge at .70 your discharge could be almost
any current, but the lower setting might make your battery happier!

Jatkiss
09-16-2005, 03:48 AM
Excellent...thank you so much !! How do you determine it so I don't come on the forums and just ask over and over.

- Jeff

ptb
09-16-2005, 05:48 AM
PTB back again!
My triton instructions say, standard charge rate for 600 ma. 0.2a
Quick charge rate 0.4a
So, your 700ma. could safely be charged at these setings.
Your discharge is about 0.1a And 3 volts per cell cutoff.

Steve
09-16-2005, 12:24 PM
I wouldn't think you need to be discharging at all unless you think there's a problem with your batt. Normally, you wouldn't be discharging except to test a batt or to rebalance one...and for that you would need a re-balancing device. So......charge your batt at .70A or less, and turn your discharge function off (if it's not off now).

I have a Triton and I'm still trying to figure out some of the functions:o

I can't imagine this world without epoxy and hot glue!

What about discharge ?

So should charge be around .65A and the Discharge stay the same?

- Jeff

Jatkiss
09-16-2005, 05:18 PM
Hehe I can't imagine a world without epoxy or hot glue either. If I could just quit going in nose down, I think the plane would really hold up much better !!

- Jeff

drzoidberg
12-18-2006, 04:42 AM
You always charge with 1C (for example a 1500mAh pack with 1,5A). \

Hi Guys,

Can I just get someone knowledgable to clarify something. I run Dualsky 1700mAH 11.1v lipos and my charging times are usually around 70 - 80 minutes using a balancer and charging at 0.95A.

If I interpret the above quote corectly does that mean I can actually charge these lipos at 1.7A? I was under the impression that you shouldnt charge any lipos above 1A. Am I incorrect?

One last question, what are the lifespans of most lipo batteries.

Thanks

jooNorway
12-18-2006, 06:01 AM
If I interpret the above quote corectly does that mean I can actually charge these lipos at 1.7A? I was under the impression that you shouldnt charge any lipos above 1A. Am I incorrect?

One last question, what are the lifespans of most lipo batteries.

Thanks

There is a difference between 1C and 1A. 1A is 1Ampere. 1C is 1 time the battery Capasity. Your battery have a Capacity of 1700mAh or 1,7Ah. Making the 1C current 1,7Amperes. You should not charge that battery at more than 1,7Ampere, but you do nothing wrong charging at lower current. It takes more time only.

An abused LiPo could last for 20 cykles and be dead. A LiPo threated nice could last 200 cykles. And which way to threat a LiPo to make it last is a theme there seems to never be an easy answer to... In the Antares project they charge their LiIon`s at low current, usually 8 hours chargetime and last year they had reached 1770 charge-discharge cykles on their batteries. But others claim charging at 1C everytime don`t reduce lifetime...
An other way to abuse LiPoes is to put a warm battery on charge, and so on.

Fred Marks
12-18-2006, 05:54 PM
I have been reading this forum quite a bit, and I can't recall anything about times. I know that different packs will require different times, but can someone give me a ballpark figure, or a rule of thumb.

Do you get one flite a day from a 3c 750 pack, or can you field charge them in 30 minutes, or 2 hours? {example}

Thanks
Terry


Terry- The FMA CelPro and Balance Pro chargers have precision digital control of charge that allows charge at up to 3C if the pack is capable. CP/BP has the intelligence to determine the max rate at which the pack can be charged and controls accordingly. If the pack is good for 3C charge, then recharge can be done in 20 minutes. The chargers also take pack temperature into account as they do the pack analysis before starting the charge run.
http://www.fmadirect.com/detail.htm?item=2193&section=45

Probedude
12-21-2006, 12:03 AM
Terry- The FMA CelPro and Balance Pro chargers have precision digital control of charge that allows charge at up to 3C if the pack is capable. CP/BP has the intelligence to determine the max rate at which the pack can be charged and controls accordingly. If the pack is good for 3C charge, then recharge can be done in 20 minutes. The chargers also take pack temperature into account as they do the pack analysis before starting the charge run.
http://www.fmadirect.com/detail.htm?item=2193&section=45

The BP and CP do not actually measure the pack's temp - there is no external thermal probe. Temp is measured on the CP or BP PCB itself and inferred to be the same as the pack. In fact the BP manual, step 1 says "Allow the Pack to Cool"

From the BP manual it does not appear that it "determines the max rate at which the pack can be charged" since it has a warning in there that "Never exceed 3C charge rate. . .Serious damage may occur to the pack including venting with flames. . ."

The Cellpro has on the fly charge rate adjustments, but I cannot tell that the BP does.

Last but more importantly I didn't see that he was asking about the CP or BP products.

Fred Marks
12-21-2006, 02:33 AM
Both CellPro and Bal Pro have "on-the-fly" (actually, sitting on the bench!) measurement of pack conditions, including the ability to take into account ambient temperature and the effect of pack temperature. The initial post asked about fast charging. CP/BP provides a reliable means of determining if pack condition is such that fast charge can be applied and the intelligence to avoid charging at a rate that might jeopardize pack integrity.

Probedude
12-21-2006, 05:33 AM
CP/BP provides a reliable means of determining if pack condition is such that fast charge can be applied and the intelligence to avoid charging at a rate that might jeopardize pack integrity.

From the BP manual

"CAUTION: NEVER exceed 3C charge rate for a BalancePro HD pack. Serious damage to the battery pack may occur including venting with flames in some instances!"

Fred Marks
12-21-2006, 06:00 AM
From the BP manual

"CAUTION: NEVER exceed 3C charge rate for a BalancePro HD pack. Serious damage to the battery pack may occur including venting with flames in some instances!"


3C is fast charge; but read the rest of the manual to see that you can override to select a charge rate manually. It would be unwise to select an 8 amp rate, e.g. for say, a 340 mAh cell. Nonetheless, CP or BP will still not allow charge at that rate if the pack is not capable of handling it. I had this checked specifically because I knew that selecting 8 amps on an AF 109 as Bob Boucher reported to me would blow a 340 Ah. Bob had inadvertently forgotten to reset the AF 109 he was using and the KOK 340 was fried. BP has been validated in that 8 amp condition to be sure that does not happen. Nonetheless. it is not wise to tempt fate by selecting a rate above 3C since very few cells have been specified as capable of anything above 3C. Before someone asks, the A123 can take up to 8C during charge but we have not readied the BP for A123 cutoff as yet.

watt_the?!
12-21-2006, 07:31 AM
what impact on life of the cells at accelerated charge rates please?

we know that high discharge rates have a direct affect on life cycle of a pack...surely the reverse is true?

pragmatically, what past-time application requires a pack to be charged in 20 mins v a 1C charge in an hour? what is the rush? even with a 20 minute delay for charging that doesnt include cooling etc and surely would extend to 60 minutes when you count battery change out etc....making the use of a second pack ready to go perfectly viable.

personally i think high rate charging and discharging is pure hype and has little to do with actual practical flying and enjoying the hobby and everything to do with commercial competition.

its like the ''old'' circa 2003 chargers and 12C packs still give the flyer 12C (or 5 minutes flying time)m and a charge time of 60 minutes....and they are priced at a steal today..

as opposed to a so called 20C pack that weighs more, gives you a ''wow'' 3 minute flight and your whizz bang new super sohpisticated charger can fast charge...and you pay for them too.

from what ive seen, modeller's flying habits havent changed....so what is the need?

please dont have a go at me, but i havent seen any real change in the technology for some time and prefer to parallel my packs, go for 10C max to maximise my cell lifetime....am i old skool already?

Cheers,

Tim

Fred Marks
12-21-2006, 03:11 PM
what impact on life of the cells at accelerated charge rates please?

we know that high discharge rates have a direct affect on life cycle of a pack...surely the reverse is true?

pragmatically, what past-time application requires a pack to be charged in 20 mins v a 1C charge in an hour? what is the rush? even with a 20 minute delay for charging that doesnt include cooling etc and surely would extend to 60 minutes when you count battery change out etc....making the use of a second pack ready to go perfectly viable.

personally i think high rate charging and discharging is pure hype and has little to do with actual practical flying and enjoying the hobby and everything to do with commercial competition.

its like the ''old'' circa 2003 chargers and 12C packs still give the flyer 12C (or 5 minutes flying time)m and a charge time of 60 minutes....and they are priced at a steal today..

as opposed to a so called 20C pack that weighs more, gives you a ''wow'' 3 minute flight and your whizz bang new super sohpisticated charger can fast charge...and you pay for them too.

from what ive seen, modeller's flying habits havent changed....so what is the need?

please dont have a go at me, but i havent seen any real change in the technology for some time and prefer to parallel my packs, go for 10C max to maximise my cell lifetime....am i old skool already?

Cheers,

Tim

Tim- Your point is well taken. It is simply a matter of personal preference and driven by the issue we see here so often in threads that start with "where can I buy xxx the cheapest" If the user wants to fly throughout a session with , say, one pack so that the expense of a second or third pack is avoided, then that individual (not you of course) likes to have fast charge even if it shortens pack life a bit. Extensive testing in our lab for a few particular cells has shown that a life of 450 cycles was achieveable when a) the packs were charged at 3C b) depth of discharge was limited to about 80% and c) the pack was charged to 100%. That life could be improved by limiting charge to 90% of full capacity.

It is impossible for us to say what the effect on service life is for every cell in the current proliferation as most of the vendors do not even substantiate service life under any conditions and few even provide validated performance data at anything other than fractional C discharge rates. Suffice it to say that, with CP/BP, the cells are treated with such respect that one will get all that can be had out of the pack without the charger contributing to damage. Statistically, by far the most pack damage occurs these days because the pack is overloaded by the user who has no idea what the real discharge rate is. When you see posts asking if it is OK for the pack to get hot, you know!

Matt Kirsch
12-21-2006, 05:01 PM
Tim,

Why do people take a look at 20C and instantly say, "3-minute flights?" Okay, a 20C rated pack discharged at 20C will only (theoretically) give you a 3-minute flight, but who really flies like that?

20C packs discharge more efficiently than say, 12C packs of the same capacity. You get better "punch," better performance, because they hold a higher voltage under load. You will run at lower throttle settings for the same power. You will fly longer on the same mAh capacity. You can reduce the amount of "paralleling" necessary, actually REDUCING overall weight and cost.

20-minute recharges... The answer to "why" should be obvious. How many times have you heard people point out 1-hour recharges as a disadvantage to electrics? You either wait or spend lots of money on extra packs, right?

Yeah, the reality is that even people who think they're going to fly continuously rarely do, it's a big selling point to have the ability to do so.

jooNorway
12-21-2006, 07:48 PM
Except for the smallest planes where weight is a big issue I have began to select batteries at a capacity which make the maxload at appr 7C. Then I get proper flights, 12-14 minutes.
But, as Matt said: the newer 20C/30C batteries deliver the punch through nearly the whole flight. This is where the profit is.

watt_the?!
12-22-2006, 08:18 AM
Tim,

Why do people take a look at 20C and instantly say, "3-minute flights?" Okay, a 20C rated pack discharged at 20C will only (theoretically) give you a 3-minute flight, but who really flies like that?

20C packs discharge more efficiently than say, 12C packs of the same capacity. You get better "punch," better performance, because they hold a higher voltage under load. You will run at lower throttle settings for the same power. You will fly longer on the same mAh capacity. You can reduce the amount of "paralleling" necessary, actually REDUCING overall weight and cost.

20-minute recharges... The answer to "why" should be obvious. How many times have you heard people point out 1-hour recharges as a disadvantage to electrics? You either wait or spend lots of money on extra packs, right?

Yeah, the reality is that even people who think they're going to fly continuously rarely do, it's a big selling point to have the ability to do so.

lol... hi Matt....actually i disagree with just about every point you've made , here,...but my viewpoint comes from the position of cost, lifecycle and practicality- these, IMO are realtime, life constraints.

regarding paralleling i disagree again, as the effect of paralleling gives more amps total. The only difference in the new higher C packs is weight- allowing more discharge- but at what expense?...cell life?...absolutely as weve seen from many tests since tyhe start of lipo technology.

anwhoo...i know you have your thoughts on the matter, and they are juxtaposed to mine, as are many others, its just that i dont think it is as clear cut as it appears...in fact i dont think it is clear at all, for the reasons already discussed.

ive always said, ask the high C advocates if they'd prefer a light weight, lower C cell and they all respond with ''heck yeah''...same as for the low C advocates.

this is ignoring the fact that cell life is optimum at 8-10C of course, which is another factor altogether...

so for me, ill take the paralleled 3s2p 10C 1500 pack giving me 3000mah over the 3s1p 20C 1500mah pack anyday...ill get more cycles, more flight time, itll be cheaper but heavier(but no where near twice as heavy)...

the 3s1p pack will be ultra expensive, last a short time (if flown at 20C), give short flight times, be lighter and be charged faster.

i guess its up to the user's standpoint.

personally i like a minimum 6 minutes flying, so i would rarely, if ever use 16C+ in a flight....im pretty sure the majority of the flying public is the same..have i inadvertantly hijacked this thread?

sorry, please delete if you see fit....its a very interesting topic IMO and one that should be had at meets during the BBQ lunch.

Tim

jb48
12-22-2006, 02:37 PM
I have 3 Polyquest 20C 2500 mAh, 2 are 3S and the other one is 2S. Charging equipment: Triton operating from a power supply or car battery; Hyperion LBA6 balancer.
Charge setting is always set at 1C (2.5 Amp).
Real life facts: both my airplanes (Easy Star and SuperStar EP) fly very well on these power packs (2S not used on the SuperStar). My flying habits are pretty much regular and I never reach cut off LVC before resuming flight. I always use the balancer between power pack and the charger. A complete charge typically give around 1800 mAh to the packs.
What I do not understand is the time it takes to full charge my lipos: about 130 minutes for the 3S and 180-190 minutes for the 2S. I noticed that when charging the 3S, the current from the charger never peak over 1.9 - 2 amp before slowing down gradually. When charging my 2S power pack, the charging current never exceed 0.7 - 0.8 amp before going down: 3 hour charge time!!!
I also have a few 2400mAh nicads which I fast charge at 3 to 4 amps, no problem! Is there something wrong with my charging equipment and/or my lipos packs? I have no clue: any of the lipos never get warm when charging and once charged they all give very high satisfaction. I always charge them with the balancer and I seriously wonder if these charging times are normal? Any idea, comment or suggestion?

Fred Marks
12-22-2006, 04:14 PM
packs.
What I do not understand is the time it takes to full charge my lipos: about 130 minutes for the 3S and 180-190 minutes for the 2S. I noticed that when charging the 3S, the current from the charger never peak over 1.9 - 2 amp before slowing down gradually. When charging my 2S power pack, the charging current never exceed 0.7 - 0.8 amp before going down: 3 hour charge time!!!
I also have a few 2400mAh nicads which I fast charge at 3 to 4 amps, no problem! Is there something wrong with my charging equipment and/or my lipos packs? I have no clue: any of the lipos never get warm when charging and once charged they all give very high satisfaction. I always charge them with the balancer and I seriously wonder if these charging times are normal? Any idea, comment or suggestion?

The subject you raise is covered in great detail in the Li Po Handbook at
http://www.fmadirect.com/tech_data/techdocs/

In the most brief reply: Li Pos have very different charge algorithm than Ni Cds. The pack can be made to reach 90% of full charge pretty quickly but the charge current tapers down asymptotically once the charger reaches constant voltage. That is, as the pack voltage approaches the regulated constant voltage the charge current decreases very slowly such that reaching 100% charge as set arbitrarily at a cut off point when current = 0.1 X the capacity of the cells may take an hour or more beyond the point at which the pack is 90% full. After you read the linked document, you may have more questions.

The FMA CellPro and Balance Pro chargers handle only Li Pos and have built - in balancing but both are capable of fast charge of your Li pos to 100% capacity in less than an hour; even as short as 20 minutes if you so choose and the charger determines that the pack is safe for 3C charge. www.fmadirect.com (http://www.fmadirect.com)

Matt Kirsch
12-22-2006, 11:02 PM
jb48,

I notice you're using a Triton. It's my understanding that the Triton charging algorithm is a bit more conservative than most. Even so, you're probably still close to 90% or higher after an hour. It's that last 10% that takes the most time.

I'd take the pack off the charger after an hour, let it rest a few minutes, and then check its voltage. If it's close to 4.2 Volts per cell, I'd call it good and go flying.

Rugar
12-22-2006, 11:26 PM
jb48,

I notice you're using a Triton. It's my understanding that the Triton charging algorithm is a bit more conservative than most. Even so, you're probably still close to 90% or higher after an hour. It's that last 10% that takes the most time.

I'd take the pack off the charger after an hour, let it rest a few minutes, and then check its voltage. If it's close to 4.2 Volts per cell, I'd call it good and go flying.

I have heard that when using a Triton with Balancer that they have a tendency to fight each other on the last 10% of charge causing the charge time to increase. I have Thunder Power Balancers and a Triton, but have never tried the Balancer with the Triton. All I use now for my Lipo's are my Astro 109's. When I get time I will try using the TP Balancer with the Triton and see what happens.

Fred Marks
12-23-2006, 02:17 AM
[quote=Rugar;128534]I have heard that when using a Triton with Balancer that they have a tendency to fight each other on the last 10% of charge causing the charge time to increase.

Gerald: That makes sense. Except for the FMA chargers, most balancers are passive and do not add current to the low cells to bring them to balance but rather bleed off current when the high cells start to exceed the pre-set voltage of the zener diode voltage limiter. Triton does limit to 90% capacity, which means aroung 4.1V, not 4.2. If the balancer is looking for higher than the 4.1V/cell of the Triton output, they are going to vounter each other and time will extend quite a bit.

docflash
11-07-2007, 01:27 AM
i understand that lipo cells have a higher energy density than nicad or nimh, but from a practical standpoint, do you get more *flight time* using several nicads that are being recharged in the field, or nimh, or lipo, or li-ion, or what? i'm still not clear.

i suppose if you had a half dozen lipos and were charging 'em continuously, you could keep a plane flying 10 minute flights indefinitely. but what happens in the real world?

jb48
11-07-2007, 02:34 PM
I made a test: I charged my lipos (Triton charger) without using my Hyperion LBA6 balancer. It cuts the charging time (1c) by about half time. Since the LBA 6 balancer can balance lipo cells on a standalone mode, I then balanced them after charging, which took 5 to 10 minutes only. I won almost an hour!

Any danger for battery life using this trick on a regular basis?

Smiky
11-07-2007, 03:07 PM
I made a test: I charged my lipos (Triton charger) without using my Hyperion LBA6 balancer. It cuts the charging time (1c) by about half time. Since the LBA 6 balancer can balance lipo cells on a standalone mode, I then balanced them after charging, which took 5 to 10 minutes only. I won almost an hour!

Any danger for battery life using this trick on a regular basis?

Whats to stop one cell going over 4.2 volts without a balancer:eek:.

Probedude
11-07-2007, 04:34 PM
Whats to stop one cell going over 4.2 volts without a balancer:eek:.

Once upon a time there was no such thing as a balancing charger, nor a balancer. Many people are still using packs that don't have balancing taps and they're doing fine.

If you don't seriously over discharge your pack, and your pack is made of quality cells, the cells seem to take care of themselves in regards to balancing.

That's my experience with my CSRC packs being charged on my Polycharge4.
I rotate them through my Cellpro 4s charger now and again but I mostly use the Polycharge4.


i understand that lipo cells have a higher energy density than nicad or nimh, but from a practical standpoint, do you get more *flight time* using several nicads that are being recharged in the field, or nimh, or lipo, or li-ion, or what? i'm still not clear. mAH capacity determines how long you'll fly. How heavy your plane is will determine how much power you need to stay in the air. A lipo plane with a 2000mAH at a voltage will fly longer than the same capacity NiMH or Nicad pack simply because the plane isn't as heavy. That said usually lipos have higher capacity than the same physical size NiMH or Nicad pack. You might not be able to fit the same capacity NiMH or Nicad pack into your plane vs a Lipo pack.

Dave

Smiky
11-08-2007, 05:31 AM
I hear what you're saying, and you make some valid points, but, and this is a big but, if you have to ask the question "Any danger for battery life using this trick on a regular basis?" I would advise to always balance charge until you have more experience, no disrespect to jb48 intended.

I've been flying electrics now for over 10 years and have yet to have a Li Po incident (now I've jinxed myself) and I get great service life out of my packs, I put this down to an anal charging regime.

Lastly cell imbalance is dependent on discharge rate as well as how much you take out of 'em. If we would all stick to the 80-80 rule (I'm guilty of breaking this rule on occasion) far fewer problems would occur.

tim--coop
09-19-2009, 03:00 PM
I had some 3s flightpower packs that I was fast-charging @the field a while ago.
It took me about 20-30 minutes to charge it to 100%.
The lipo's where very hot after charging and died quickly. I think they only survived 20 fast-charges or so :p

I now just buy cheapo lipo's from ebay.
Just order 6-8 lipo's and you're good to fly whole day long :)


Are Ebay lipo's any good?
- They provide a little less power
- I need to balance them with every charge
But for it's price they are very good in my opinion :)
I bought 4 lipo's for the price I pay for 1 lipo at my local store.

Greets from Belgium :)

everydayflyer
09-19-2009, 06:19 PM
Two points.

First this thread is a very old one.

Second I have been charging Thunder Power pro lites at 3C for 4 years and it has not reduced their life by any measurable amount.

There are now 5C and even 6C charge capable Lipolys and the chargers / balancers in use to day are overall much better than ones from years ago.

My hyperion G3 3S 3300 now has over 180 dischrages on it and most charges have been at 3 to 5C.

Thread here

http://www.wattflyer.com/forums/showthread.php?t=47632

Thunder Power Pro power 40 Thread here.

http://www.wattflyer.com/forums/showthread.php?t=43403


Charles

tim--coop
09-19-2009, 09:00 PM
That's nice !!!

Yes it's an old thread, got here trough google :)