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Old Apr 21, 2010, 09:44 PM
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110+ Min to charge a 3S 2200mah Lipo battery?

I'm in the process of starting down the road of the eletric's, and bought a
Triton Eq-2. I'm charging ( used ) Lipos for the first time tonight to take to the feild tomorrow and fly, and the first Lipo ( both are the same betteries) took less then a hour to charge, and the Trition Eq2 said " END "

The 2nd battery, seems to hover allot in the last 30 min, at 0.2 amps, which is barlley nothing. It went from 1770 mah to 1880 in 30 min, around
0.3 amps.

First question: Why does it take so long to charge such a small Lipo

Second question : I just bought a Turnigy 5S 3000mah battery for my bigger Extra I'm buidling, should I have bought two of the same batteries, so while ones charging I can still fly?

I couldnt imagine waiting at the feild for an hour and a half for a battery to charge.

Their was a guy their today, using a " Venom " charger, and he puts it on
" fast charge " and it took around 30 min to charge a 4S 3000 mah Lipo. That seemed great.

After 110+ min, the battery is " Still charging "

Is this normal?
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Old Apr 21, 2010, 09:56 PM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
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Tritons are well know as being slow. A notmal 1C charge takes 70 to 90 min. so nothing unusual here unless it was anew LiPoly and was at 3.85 per cell as it should haven been.

If a battery has inbalanced cells it will take longer to charge. On most LiPoly charger Fast or Faster charge setting merely stops the CV stage sooner and the battery does not get balanced or toped off as well. No problem as anything over 4.15 per cell is plenty full enough.

Some LiPolys can be charged at up tp 6C and with a good charger/balance it takes me less than 15 minutes to charge one.

Charles
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Old Apr 21, 2010, 10:34 PM
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Originally Posted by everydayflyer View Post
Tritons are well know as being slow. A notmal 1C charge takes 70 to 90 min. so nothing unusual here unless it was anew LiPoly and was at 3.85 per cell as it should haven been.

If a battery has inbalanced cells it will take longer to charge. On most LiPoly charger Fast or Faster charge setting merely stops the CV stage sooner and the battery does not get balanced or toped off as well. No problem as anything over 4.15 per cell is plenty full enough.

Some LiPolys can be charged at up tp 6C and with a good charger/balance it takes me less than 15 minutes to charge one.

Charles
\


Thanks, When you say " Some LiPolys can be charged at up tp 6C and with a good charger/balance it takes me less than 15 minutes to charge one."

Does that mean the charger I bought isnt a good charger, or the batteires just may not be ballanced well?

I bogught the planes, and it came with the Lipos, so i dont know the history of the batteries. Their make is " Mystery " So maybe their a cheap battery also

I was hoping spending $200 on a charger, would be a good charger.

Also, when you get batteries, oce they have a unballanced cell, does the charger fix it, or it will always be like that
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Old Apr 22, 2010, 02:26 AM
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Letchworth, Great Britain (UK)
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Quote:
Originally Posted by fltekdiver View Post
I'm in the process of starting down the road of the eletric's, and bought a
Triton Eq-2. I'm charging ( used ) Lipos for the first time tonight to take to the feild tomorrow and fly, and the first Lipo ( both are the same betteries) took less then a hour to charge, and the Trition Eq2 said " END "

The 2nd battery, seems to hover allot in the last 30 min, at 0.2 amps, which is barlley nothing. It went from 1770 mah to 1880 in 30 min, around
0.3 amps.

First question: Why does it take so long to charge such a small Lipo

Second question : I just bought a Turnigy 5S 3000mah battery for my bigger Extra I'm buidling, should I have bought two of the same batteries, so while ones charging I can still fly?

I couldnt imagine waiting at the feild for an hour and a half for a battery to charge.

Their was a guy their today, using a " Venom " charger, and he puts it on
" fast charge " and it took around 30 min to charge a 4S 3000 mah Lipo. That seemed great.

After 110+ min, the battery is " Still charging "

Is this normal?
Up until recently, it's been recommended to charge LiPo batteries at what is known as a "1C" rate. That means for a 1800mAh battery, for instance, you set the charger for 1.8 amps max; for 3000mAh you set it at 3.0 amps max.

In theory, charging a fully discharged pack at 1C rate should take one hour, irrespective of what size the battery is. In practice, LiPo chargers charge at whatever rate you've set, until the battery reaches 4.2 volts per cell. At that point the charger starts reducing the charge rate (as you've seen) to hold the pack at 4.2 volts per cell, until the rate needed to hold 4.2 volts gets down to something like 0.1 amps, at which point it will stop the charge. This constant-voltage reduced-amp phase of the charge can take quite a while, but only adds about 5 or 10% more capacity, so you can stop the charge at that point without losing much in the way of flying time. Charge time can also be influenced by how much balancing the cells need during charging.

Many modern LiPo packs can be charged safely at rates higher than 1C, but don't attempt that unless the manufacturer has clearly said so. Charging at 2C instead of 1C (i.e. 3.6 amps max. for an 1800mAh pack) will half the charging time

Some people who charge at the flying field take 3 packs with them -- while they're flying one, another's on charge and the third is cooling down from its flight (don't charge while they're still warm). With a bit of socialising between flights , and a reasonable charge rate, you should be able to fly all day like that.
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Old Jun 01, 2010, 03:12 PM
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Originally Posted by abenn View Post
Up until recently, it's been recommended to charge LiPo batteries at what is known as a "1C" rate. That means for a 1800mAh battery, for instance, you set the charger for 1.8 amps max; for 3000mAh you set it at 3.0 amps max.

In theory, charging a fully discharged pack at 1C rate should take one hour, irrespective of what size the battery is. In practice, LiPo chargers charge at whatever rate you've set, until the battery reaches 4.2 volts per cell. At that point the charger starts reducing the charge rate (as you've seen) to hold the pack at 4.2 volts per cell, until the rate needed to hold 4.2 volts gets down to something like 0.1 amps, at which point it will stop the charge. This constant-voltage reduced-amp phase of the charge can take quite a while, but only adds about 5 or 10% more capacity, so you can stop the charge at that point without losing much in the way of flying time. Charge time can also be influenced by how much balancing the cells need during charging.

Many modern LiPo packs can be charged safely at rates higher than 1C, but don't attempt that unless the manufacturer has clearly said so. Charging at 2C instead of 1C (i.e. 3.6 amps max. for an 1800mAh pack) will half the charging time

Some people who charge at the flying field take 3 packs with them -- while they're flying one, another's on charge and the third is cooling down from its flight (don't charge while they're still warm). With a bit of socialising between flights , and a reasonable charge rate, you should be able to fly all day like that.


Are fast charge rates always "Doubled"?

example,

2000mAh normal rate= 2.0a. Fast rate 4.0a 2000mAhx2=4000mAh.

Can i just increase it to say 3.0 and just charge a little faster? or is it always x2?


Thanks.....
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Old Jun 01, 2010, 03:27 PM
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Haralson County GA. USA
Joined Oct 2004
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Your math is correct and no there are no times X points.

2.5 A would be 2-1/4C for a 2000 mAh . I charge 5c charge capable LiPoly of 3300 mAh anywhere from 10 to 16A depending on how big of a hurry I am in.

Charles
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Old Jun 01, 2010, 03:44 PM
Rc Flying is my Sanity!
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United States, CA, San Jacinto
Joined Mar 2010
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Quote:
Originally Posted by everydayflyer View Post
Your math is correct and no there are no times X points.

2.5 A would be 2-1/4C for a 2000 mAh . I charge 5c charge capable LiPoly of 3300 mAh anywhere from 10 to 16A depending on how big of a hurry I am in.

Charles


Thank you.............
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