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a123 or life batteries rx and tx

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Old 08-24-2012, 11:07 AM
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Walfam
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Default a123 or life batteries rx and tx

i am considering using a123 or life batteries for my rx and tx. I would like to get an idea what the pattern community is using. I notice that all the rx a123 batteries are 6.6 volts. Will this cause a problem on my digitial servos that only go to 6.0 v? Also, I know they have a123 life batteries for tx but I have not found any in the 7.6 range or that will fit in my Airtronics SG-10. I have a cellpro charger and found a place where I can charge do a single charge thru the switch. Any help will greatly be appreciated.

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Old 08-24-2012, 12:03 PM
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Default RE: a123 or life batteries rx and tx

I use LiPo for Rx power with regulator and without regulator for HV servos.

However, make sure the servos can handle the higher voltage (little over 7 volt off the charger) if don't plan on using regulator.
Some servo manufacturer specifically has maximum voltage.

Some people said their servos buzz initally, but works fine as the voltage drop to nominal voltage.

I haven't seen LiFe transmitter pack made for the Airtronics SG-10. I am still using the NiMH stock. Better ask Airtronics or Airtronics sponsored pilots. Most of the guys are using LiPO if they go optional.
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Old 08-24-2012, 02:17 PM
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Default RE: a123 or life batteries rx and tx

For my SD-10G I am using the fromeco 7.4v 2600mah Lithium Ion. I also use the same battery for my Rx on a Shulman Aviation 6v regulator. I flew all week at NATS in Muncie and didn't have to charge my Tx battery one time.

http://www.fromeco.org/Products/01FRC2600-100/

Thanks,
Chris
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Old 08-24-2012, 02:30 PM
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Default RE: a123 or life batteries rx and tx

I've been using unregulated 2S LiFePO4 packs in everything I fly except my Abbra. That was set up for lipo and I simply have been too lazy to change it. I've used unregulated LiFePO4 in gliders, helis, and planes with no issues at all.

I fly Futaba and have used the R6004HF, R6106HFC, R617FS, R608FS, R6008HS, R6014FS, and R7008SB with these packs.

Servo wise I've run JR281, JR3421, JR8411, 8417.

Futaba 3150, 3155, 9252, BLS252, BLS153, 9255, 9650, 9156, 9157, 9551.

Align DS610, DS620, DS650

My next pattern plane will have unregulated 2S LiFePO4 in it. My experience has been that the packs drop to 6.6 volts fairly quickly and hold there for a very long time. They retain charge between uses, and have a good capacity to weight ratio.

I use the Hyperion packs and have the 850, 1700, 1450, 2100 and 3000 mAh packs. I charge them with my Hyperion DUO chargers.

The only servos I have heard that have had issues were a couple of MKS glider servos where 6 volts was the absolute max. In general any servo that can handle a 5-cell NiMH will be just fine with an unregulated 2S LiFePO4 pack.
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Old 08-24-2012, 05:44 PM
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Default RE: a123 or life batteries rx and tx

The SD-10 uses a 6 cell nimh battery so a 2 cell lipo works perfectly. There is a big piece of foam in the battery compartment that will give you a lot of room. I bought a 2 cell 1800mah lipo but rarely use it since I get over 2 hours of use from the stock battery. A 2100 or more may fit.

An unregulated A123 will work fine fo rx but won't be as consistent or as light as a regulated lipo. For an e powered plane 600 or 800 mah is plenty. If you do go the A123 route keep in mind there voltage drop can be severe at the end of the discharge curve and can bite you.
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Old 08-24-2012, 06:22 PM
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Default RE: a123 or life batteries rx and tx

I have 2 stock battery packs for my SD10. I cycled them as the instructions in the manual said to. I get 17, 10 minute flight per pack before I have to recharge. I just run them down all the way to the alarm buzzer then recharge it.

Evan
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Old 08-24-2012, 06:30 PM
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Default RE: a123 or life batteries rx and tx


Quote:
ORIGINAL: Anthony-RCU

An unregulated A123 will work fine fo rx but won't be as consistent or as light as a regulated lipo.

Take a look at this discharge curve. It uses a 500 mA load. That is higher than most pattern planes will pull (in general) Notice that there is virtually no voltage depression and it takes a long time to reach the end. I simply determine what my average use per flight is and then figure the max number of flights I can get. Then I only fly 75% of the max.

A 2S 850 mAh LiFePO4 pack from Hyperion weighs 48.8 grams and requires no regulator.

A 2s 900 mAh TP lipo weighs 49 grams and requires a regulator (unless you have HV servos).

The TP 730 mAh Pro-lite is 39 grams and it too needs a regulator.

I like the constant 6.6 volts I get with the LiFePO4 packs. On my 62" Osiris I have the telemetry which tells me current voltage along with the high and low. On that plane the current, high and low are always 6.6 volts.
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Old 08-24-2012, 07:37 PM
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Default RE: a123 or life batteries rx and tx


Quote:
ORIGINAL: cdodom

For my SD-10G I am using the fromeco 7.4v 2600mah Lithium Ion. I also use the same battery for my Rx on a Shulman Aviation 6v regulator. I flew all week at NATS in Muncie and didn't have to charge my Tx battery one time.

http://www.fromeco.org/Products/01FRC2600-100/

Thanks,
Chris
Same here with the Fromeco Li-Ion for the TX. Lasts a long time.

For RX, primary is a Dimension Engineering VHVBEC and for back-up a 350mAh LiPo with a Tech-Aero reg. The BEC is set at 6V and the reg at 5.75V so the back-up LiPo stays charged for a really long time. Unfortunately I had a real chance to check it when a defective arming plug let me down, but fortunately the back-up saved the model.
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Old 08-25-2012, 02:48 PM
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Default RE: a123 or life batteries rx and tx

Thanks Gentlemen,

This gives me a couple of options and i will research them and finds what fits my style the best. I do plan to get some heavy practicing this fall , weather permiting.

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Old 02-18-2013, 09:18 PM
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Default RE: a123 or life batteries rx and tx

Any more reports of successes and weights of LiFe Rx packs? I've used 2s lipos and regulators for a few years now, no issues, and I can fly a full day on two 450mah packs. No real reason to change, except maybe less failure points and weight?

Ed's regulators are crazy light, as are some 2s lipos.
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Old 02-19-2013, 04:52 AM
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Default RE: a123 or life batteries rx and tx

for the rx I use a dual reg, redundant system with the primary power coming from a CC BEC Pro and the backup being a 730ma lipo at storage charge. other than regular voltage checks and verifying the backup system functions this has been maintanence free. no charging, no worries
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Old 02-19-2013, 05:29 AM
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Default RE: a123 or life batteries rx and tx

I use 2S Hyperion LiFePO4 packs in everything I fly ranging from 3 different helis, my Osiris and Abbra, and all if my F3J/TD planes. I use packs between 850 mAh and 2,100 mAh. I've gotten nothing but solid performance for the nearly 3 years I've been using these packs.

I buy all mine from RCLipos. com http://www.rclipos.com/Hyperion_Receiver.htm Great service, free shipping charges

No regulators, no issues. Just a solid 6.6 volts for nearly the entire useful charge.
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Old 02-19-2013, 08:20 AM
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Default RE: a123 or life batteries rx and tx


Quote:
ORIGINAL: gaRCfield

Any more reports of successes and weights of LiFe Rx packs? I've used 2s lipos and regulators for a few years now, no issues, and I can fly a full day on two 450mah packs. No real reason to change, except maybe less failure points and weight?

Ed's regulators are crazy light, as are some 2s lipos.
.
I run two of Ed Alt's adjustable regulators in parallel to the receiver power bus - no switches.
.
The first one I set to 5.9V and gets its power from pins 1 and 3 (tap first two cells) of the balance plug of the motor battery. The other regulator is set to 5.7V output and is powered from a 2S-250Mah battery. When the 5.9V regulator is powered up, it shuts off the 5.7V regulator, thus keeping the charge in the 2S-250 backup battery for weeks. The radio gets it power from cells 1 and 2 of your motor pack. The radio draw is imperceptible compared to the motor draw and I've never been able to detect a difference in those two cells vs. the other 8. Of course, the charger tops every cell off (including the two you used for radio) each flight.
.
No batteries to charge or check, except the backup battery gets charged every couple months.
.

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Old 02-20-2013, 09:27 AM
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Default RE: a123 or life batteries rx and tx

I use a pair of 1100 ma A123 cells - direct to rx and a flight log velcroed to the pack- read the log each flight ( have to remove the bricks each time for recharging so this is not an issue)
in 7 mins the 11 lb model uses very little current - four to six flights safe - but the batts get changed after four flights
There isn't a better setup -in my opinion.
I really distrust regulators - just use em when there is no other choice.
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