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Old 10-16-2018, 05:42 AM
Hank Durrer is offline
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LIFE Batteries

I have two questions that I hope someone out there can assist me with. First, what is the recommended re-charge voltage? In other words, after fully charging the 2S 3400mah battery, it reads 7.2 and drops to 6.6 as normal. I have flown 4 to 5 flights and when checking the battery voltage, I see the voltage has dropped very little, maybe to 6.5 or 6.2. At what point on the voltage scale should I be getting concerned and recharge?????

Second, are there 1S LIFE transmitter batteries available? If so, who has them. All I see are LIPO and I really would like to go with LIFE for the obvious reasons. Can anyone help me with this??
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Old 10-16-2018, 06:02 AM
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Life bats don't drop after a CPL flights like other bats. They keep their output fairly smooth till they can't then they drop quickly. The method everyone is using is to fully charge at a rate relative to your capacity.....so if you are charging a 3000 mAh life I would charge at 3 amps......2000 mah at 2 amps and so on. You will not be able to use a battery checker for a life if your trying to see how much your voltage has dropped ..these bats don't drop like say a nicad would after a CPL flights. You have to fully charge and fly a CPL flights then recharge to count how many mAh it takes to recharge... divide thoes mAh by how many flights and that gives you your usage per flight. Then you can figure how many flights you can get till you have used 1/2 the capacity of that battery. So if you are using 3000 mAh bats and after 4 flights you put back 1200 mAh when recharging you are using 300 mAh per flight and could probably fly 5 flights . Never use below half the capacity of a life bat....
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Old 10-16-2018, 06:57 AM
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wrongwayfeldman
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This may or may not fit your particular transmitte.
Tower hobbies part number....LXHDJN
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Old 10-16-2018, 08:35 PM
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Ponyboy is dead on correct. I generally expect 300-400mah per pack per 12min flight and that figure holds true in all of my planes (up to 70cc). On new planes I fly 2, 8 minute flights and re charge. Count the mah and then make sure the numbers work out before adding time/flights. I put enough capacity in the planes to get a full day in with about 60% of mah used and leave the packs at that voltage until the plane is flown again. Turnigy nanotech batteries are a great value, all of my packs are still in service including the original pack from 5 years ago (and one crash).
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Old 10-17-2018, 04:04 AM
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Thanks guys, I appreciate the info.
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Old 10-17-2018, 08:06 AM
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I think all previous posts are on the mark
Last weekend I flew Imac Basic with a 50cc Extra and after the whole day
3 known rounds and 1 unknown (Approx. 50 -60 minutes run time) I put 1000 MAH in 2 (2100 mah) receiver batteries and 250 in the 1900MAH Ignition battery
Figures to about 20 to 25 ma per minute
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Old 10-28-2019, 10:06 PM
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Does anyone know why, for the most part anyway, Life batteries specify on the label that they are for transmitter or receiver? Surely a 2 cell 2100 mAh could be good for either?
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Old 10-29-2019, 12:03 AM
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Quote:
Originally Posted by grungthep View Post
Does anyone know why, for the most part anyway, Life batteries specify on the label that they are for transmitter or receiver? Surely a 2 cell 2100 mAh could be good for either?
If I'm not mistaken LiFe transmitter batts are 3cell (3S)=9.9v
LiFe Rcvr batts are 2cell (2S)= 6.6v. difference in voltage
that stamp is a typo and must have passed through QC lol as far as I know transmitters need 9.9v to operate
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Old 10-29-2019, 01:17 AM
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Quote:
Originally Posted by rsnow View Post
If I'm not mistaken LiFe transmitter batts are 3cell (3S)=9.9v
LiFe Rcvr batts are 2cell (2S)= 6.6v. difference in voltage
that stamp is a typo and must have passed through QC lol as far as I know transmitters need 9.9v to operate

Thanks rsnow but no, they are both 2 cell. I have checked and if you look around, you will see plenty of 2 cell for transmitter available. Thanks for the comment though. Its still a mystery!!!
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Old 10-29-2019, 02:11 PM
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Quote:
Originally Posted by grungthep View Post
Does anyone know why, for the most part anyway, Life batteries specify on the label that they are for transmitter or receiver? Surely a 2 cell 2100 mAh could be good for either?
Just a guess but I would think the connector would be the biggest difference.
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Old 10-31-2019, 06:48 PM
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Quote:
Originally Posted by rsnow View Post
If I'm not mistaken LiFe transmitter batts are 3cell (3S)=9.9v
LiFe Rcvr batts are 2cell (2S)= 6.6v. difference in voltage
that stamp is a typo and must have passed through QC lol as far as I know transmitters need 9.9v to operate
Transmitters use a variety of voltages.

In the old days of 72 MHz 8 cell NiCD was standard (9.6), but more recently 6cell Ni (7.2), 2s LiPo (7.4), 2s LiFe (6.6), and even 4cell Ni (4.8) have been used in various brands and models.

The TX vs. RX rating of these pack has to do with discharge c-rate. The Tx packs are probably using cheaper/lower binned cells that are only rated for a lower discharge rate than the Rex versions.

For comparison, real A123 brand LiFe are rated for 30C/60C burst so all of these off brand packs are pretty weak....
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Old 10-31-2019, 07:22 PM
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For comparison, real A123 brand LiFe are rated for 30C/60C burst so all of these off brand packs are pretty weak....
Can you still find "real A123 batteries" anymore?
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Old 10-31-2019, 07:38 PM
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Can you still find "real A123 batteries" anymore?
You mean like these:
https://www.radicalrc.com/category/A...ells-Packs-199
or packs made using A123 Systems LiFePO4 cells like these
https://www.batteryspace.com/a123-li...iABEgLO1vD_BwE
like those shown on the Taildragger site:
http://www.taildraggerrc.com/a123-batteries/
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Old 10-31-2019, 07:41 PM
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http://a123batteries.com

Much better price than from hobby shops. Shipping is usually $20, however. A123 cells are now branded as "Lithiumwerks", fyi.
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Old 10-31-2019, 10:20 PM
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http://a123batteries.com

Much better price than from hobby shops. Shipping is usually $20, however. A123 cells are now branded as "Lithiumwerks", fyi.
Thx for the infor on the new branding, aka Lithiumwerks......was wondering if they were just your typical Chinese knockoffs
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