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-   RC Radios, Transmitters, Receivers, Servos, gyros (https://www.rcuniverse.com/forum/rc-radios-transmitters-receivers-servos-gyros-157/)
-   -   6.6 life receiver battery (https://www.rcuniverse.com/forum/rc-radios-transmitters-receivers-servos-gyros-157/11493035-6-6-life-receiver-battery.html)

drdave427 04-26-2013 05:37 PM

6.6 life receiver battery
 
I have a new life battery pack that I was going to use to power my AR6200 and servos. I thought I was buying a 6 volt pack but it says 6.6 volt on the pack. Is it safe to use this 6.6 volt pack ? I think I read Spektum says the AR6200 will go to 7.2 but I wasn't sure. Thanks for you help !!

BuschBarber 04-26-2013 05:54 PM

RE: 6.6 life receiver battery
 


ORIGINAL: drdave427

I have a new life battery pack that I was going to use to power my AR6200 and servos. I thought I was buying a 6 volt pack but it says 6.6 volt on the pack. Is it safe to use this 6.6 volt pack ? I think I read Spektum says the AR6200 will go to 7.2 but I wasn't sure. Thanks for you help !!
In most cases, Rx's will support 8.4v, which is the charged voltage of a 2cell LiPo or LithIon battery pack. It is the servos that you have to check out. There are some servos on the market that will only work at 5v. The JR 791 Retract servo is a good example. If the servos you use are rated foor 6v, then 2cell LiFe/A123 Rx battery packs are fine.

Keep in mind, the Nominal voltage for a battery pack is lower than the Fully Charged voltage. LiPos have a Nominal Voltage of 3.78v per cell, but charge to 4.2v per cell. If a device is rated for 7.4v (Nominal Voltage for a 2cell LiPo pack) then it will be fine at 8.4v (fully charged 2cell LiPo pack). There are HV servos that are compatible with 2cell LiPos and run fine at 8.4v.

LiFe batteries have a very flat discharge curve and sit at 3.3v/cell until they are fully discharged. LiPos will slowly lose voltage as they discharge so they are easy to monitor with an Expanded Scale Voltmeter (ESV). LiFe batteries will not show a measurable voltage drop so you need to keep track of how much time they have been in use in order to determine when to recharge them.

JCINTEXAS 04-26-2013 05:56 PM

RE: 6.6 life receiver battery
 
I have been flying with LiFe receiver batteries for over 2 years with excellent performance. I used NiCads for many years...then switched to NiMH....then moved on the LiFe which are the best yet. They hold their charge over an extended period of time and they don't develop a "memory" as the NiCads do. They are safer than LiPo batteries and no voltage regulator is needed. From my own experience and everything I have read on batteries, these are the best batteries yet for modern radios including digital servos.
JC

I don't always fly R/C...but when I do, I fly FASST. Fly well my friends.

snuts 04-26-2013 06:23 PM

RE: 6.6 life receiver battery
 

ORIGINAL: drdave427

I have a new life battery pack that I was going to use to power my AR6200 and servos. I thought I was buying a 6 volt pack but it says 6.6 volt on the pack. Is it safe to use this 6.6 volt pack ? I think I read Spektum says the AR6200 will go to 7.2 but I wasn't sure. Thanks for you help !!
Yes.

Product Specifications
Type:Full Range Aircraft Receiver# of Channels:6Modulation: DSM2/DSMXBand:2.4GHzLength:1.19 in (30.1mm)Width:1.03 in (21.6mm)Height:0.48 in (12.3mm)Weight:0.35 oz (10g)Voltage Range:3.5–9.6VAntenna Length:Main Rx: 30mm (2); Remote Rx: 30mm (2)

drdave427 04-26-2013 06:36 PM

RE: 6.6 life receiver battery
 
OK - thanks guys. Now one more issue. My old receiver pack has 3 wires like a servo wire but the life battery only has two. My plane has a charge jack/switch on it also. Is the third wire something to do with charging the old NIMH pack ?? I plugged the life battery into the jack than runs to the switch then on to the receiver and everything worked but I was worried about that third wire.
Thanks again for the help !!

BuschBarber 04-26-2013 07:52 PM

RE: 6.6 life receiver battery
 


ORIGINAL: drdave427

OK - thanks guys. Now one more issue. My old receiver pack has 3 wires like a servo wire but the life battery only has two. My plane has a charge jack/switch on it also. Is the third wire something to do with charging the old NIMH pack ?? I plugged the life battery into the jack than runs to the switch then on to the receiver and everything worked but I was worried about that third wire.
Thanks again for the help !!
Most batteries have two wires, a Red(Positive) and a Black(Ground). Servos have a 3rd wire(White) which is the Signal. A 3 wire Switch Harness is usually designed and compatible with Direct Servo Control(DSC) receivers. In the days of 72Mhz, there were some transmitters and receivers that were DSC compatible. You could connect a DSC cable between the transmitter and receiver or transmitter and switch harness which would allow the transmitter to control all the channels on the receiver without transmitting RF. If you were at a model meet and your transmitter was impounded, you could sign it out, connect it between the transmitter and receiver in the aircraft, turn on the transmitter, and set up your aircraft without needing a Frequency Pin.

In the 2.4Ghz era, you can Bind Spektrum receivers by either inserting the Bind Plug in the Bind port on the receiver or inserting Bind Plug in the charge port on a 3 wire DSC compatible Switch Harness. This would not be possible with a Non 3 wire Switch Harness.

Zeeb 04-27-2013 05:38 AM

RE: 6.6 life receiver battery
 
Well one of reasons the A123/LiFe batteries might have a two wire lead and a three wire lead, is balance charging.

The two wire lead would be for discharging or powering the model, the three wire lead will typically use the signal wire as a balance lead for charging. On the Spektrum/JR 2.4GHz radios, if you plug that three wire lead into the rx and then try to bind the rx, you'll let the magic smoke out of the rx.... :(

Best to do a bit more research on what you have for a configuration of the wiring as there are a number of ways to do things with three wire HD switches and these batteries.

drdave427 04-27-2013 05:48 AM

RE: 6.6 life receiver battery
 
No I understand the balance charge lead of the battery. It is a Turnigy Nano tech and actually has 3 harnesses. The white balance charge lead , the black JR/Spektrum type plug I'm using(red and black wires) and a small red plug with red and black wires. I forget what that red type of plug is called but I only needed the JR/Spektrum plug and the balance/charge lead. Thanks again for the info !!

A.T. 04-27-2013 01:15 PM

RE: 6.6 life receiver battery
 


<span style="font-size: smaller;">ORIGINAL: drdave427
OK - thanks guys. Now one more issue. My old receiver pack has 3 wires like a servo wire but the life battery only has two.
My plane has a charge jack/switch on it also. Is the third wire something to do with charging the old NIMH pack ??
I plugged the life battery into the jack than runs to the switch then on to the receiver and everything worked but I was worried about that third wire.
Thanks again for the help !!</span>

<span style="font-size: smaller;">ORIGINAL: drdave427 No I understand the balance charge lead of the battery. It is a Turnigy Nano tech and actually has 3 harnesses.
The white balance charge lead , the black JR/Spektrum type plug I'm using(red and black wires) and a small red plug with red and black wires.
I forget what that red type of plug is called but I only needed the JR/Spektrum plug and the balance/charge lead. Thanks again for the info !! </span>
Most of the LiFe batteries now have three leads.
1. Three wire balance lead.
2. S-01 (Hitec / JR) servo plug with Red (+) and Black (-) leads to fit many different Tx.
2. JST (Tamiya) power plug with Red (+) and Black (-) leads to fit many other Tx such as GWS
or use to power small boats, mini cars etc.

Much more information available under sub sections
"Battery Care, Performance &amp; DIY Battery Packs."
and
"Radio Systems, Accessories, Alterations and FAQ" at
Alan's Hobby, Model &amp; RC FAQ Web Links

Alan T.
.


drdave427 04-27-2013 01:59 PM

RE: 6.6 life receiver battery
 
Thanks Alan I have been reading about all this today (it's pouring down outside) you've given me MUCH MORE to read !!

ThunderBoat42 05-02-2013 02:51 PM

RE: 6.6 life receiver battery
 
Interesting read.   Also poses another question.  I am still using my old 72mhz Futaba 8ua radio.   I just purchased the LiFe receiver batteries and the Hitec X4 charger to support them (and any future charging needs I may have) .  That said, Should I use a reg ?   The LHS says I am fine, but they may be thinking about the Spectrum Radio's/Receivers they carry.  <div>
</div><div>
</div>

A.T. 05-02-2013 03:40 PM

RE: 6.6 life receiver battery
 


<span style="font-size: smaller;">ORIGINAL: ThunderBoat42
Interesting read. Also poses another question. I am still using my old 72mhz Futaba 8ua radio.
I just purchased the LiFe receiver batteries and the Hitec X4 charger to support them (and any future charging needs I may have) .
That said, Should I use a reg ? The LHS says I am fine, but they may be thinking about the Spectrum Radio's/Receivers they carry.</span>
No problem with receivers but the higher the volatge the more speed/power is produced by the servo which also increases heat,
wear and tear which shorten the life of the servo. Sure, a fully charged 5 cell NiMH/NiCD battery is at same voltage but not for long.
Majority of known users fit a good UBEC (aka SBEC or Switchmode Regulator fixed at 5.5v to best of all results.
<span class="important"> 4A BEC is minimum for sports Nitro/GP models but when weight is not a problem, 10A is best overall.</span>

. <span class="important">CC BEC Switching Regulator

Much more information available under sub sections
"Battery Care, Performance &amp; DIY Battery Packs."
"ESC &amp; BEC - Setup to prevent majority of all RF Problems, Brownouts &amp; Crashes"
"Glitches &amp; Jitter in Receiver, Servo &amp; ESC - Causes and Cures"
"Servo - Alterations, Calculators, Databases, Leads, Repairs, Convert to an ESC or winch &amp; FAQ."
below
"Radio Systems, Accessories, Alterations and FAQ" at
Alan's Hobby, Model &amp; RC FAQ Web Links

Alan T.

</span>

Mikecam 05-02-2013 11:34 PM

RE: 6.6 life receiver battery
 
Thunder use this link and plug in your servo's you are using. As long as your servo's are not rated for 4.8 VOLTS ONLY then no need for the reg's. In fact a 5 cell nicd/nimh will have more volts then the LiFeP04 pack. And contrary to what AT said I think most users are running their LiFeP04 packs straight to the Rx. I know I am and many others, including JC from this thread.

http://www.servodatabase.com/

As Buschbarber stated the JR 791 servo is rated for 4.8 volts only. See here. http://www.servodatabase.com/servo/jr/791 You can see it shows 4.8 volt specs only.

This servo ( http://www.servodatabase.com/servo/futaba/s3001 ) is good for both 4.8 and 6.0 volts so if it can handle the 7.2 volts off a freshly charged nimh it can handle the 6.6 from a life pack.

So as long as your servo's are rated for 6.0 volts your good to go as is. If not then you could use a reg. or do what more of us are doing and use a diode to drop the voltage. Reg's can fail but diode's are much less prone to it. :)


:)

A.T. 05-03-2013 03:43 AM

RE: 6.6 life receiver battery
 


<span style="font-size: smaller;">ORIGINAL: Mikecam
Thunder use this link and plug in your servo's you are using. As long as your servo's are not rated for 4.8 VOLTS ONLY then no need for the reg's. In fact a 5 cell nicd/nimh will have more volts then the LiFeP04 pack. And contrary to what AT said I think most users are running their LiFeP04 packs straight to the Rx. I know I am and many others, including JC from this thread.
http://www.servodatabase.com/
As Buschbarber stated the JR 791 servo is rated for 4.8 volts only. See here. http://www.servodatabase.com/servo/jr/791 You can see it shows 4.8 volt specs only.
This servo ( http://www.servodatabase.com/servo/futaba/s3001 ) is good for both 4.8 and 6.0 volts so if it can handle the 7.2 volts off a freshly charged nimh it can handle the 6.6 from a life pack.
So as long as your servo's are rated for 6.0 volts your good to go as is. If not then you could use a reg. or do what more of us are doing and use a diode to drop the voltage. Reg's can fail but diode's are much less prone to it. </span>
Please re-read my post "Majority of <u>known</u> users "means just that, not worldwide.
Good reading:<a href="http://www.rcgroups.com/forums/showthread.php?t=914941">
. Voltage Regulators and LiFe Battery Packs ***
. Battery (Receiver packs) . LiFePO (aka A123 &amp; LiFe)
. </a>Battery (Receiver packs) . LiFePO (aka A123 &amp; LiFe) - <u><span style="color: rgb(255, 0, 0);">Alert re False Labels &amp; excess voltage</span></u>
. Servo - <u>Burnout. Cause &amp; Prevention</u>

Alan T.



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