Wattflyer RC Network: RC Universe :: RCU Magazine :: RCU Forums :: RCU Classifieds :: RCU User Reviews :: RCU YouTube
Home Who's Online Calendar Today's Posts RealTime Post Spy Mark Forums Read
Go Back   WattFlyer RC Electric Flight Forums - Discuss radio control eflight > R/C Electric Power - Batteries, Chargers, ESCs and More > Batteries & Chargers
Register Members List Wattflyer Extras Articles Search Today's Posts Mark Forums Read Social Groups

Batteries & Chargers Discuss Li-P, Li-Ion, NiMh, Nicad battery technology and the chargers that juice 'em up!

Thank you for your support (hide ads)
Reply
 
Thread Tools Display Modes
Old 08-07-2012, 12:53 AM   #1
piercethesky
Member
 
Join Date: Aug 2012
Posts: 21
Thanked 2 Times in 2 Posts
iTrader: (0)
Friends: (0)
Default Life batteries for transmitter use?

I recently noticed life batteries being advertised for use in a transmitter. I have been around for a while but have never known anyone personally who has first hand experience with them. I am currently using my dx8 and also have been using my turnigy 9x a bit more now that I finally have it modded.

Now, I went the lipo route with the dx8 and that was a small fortune all by itself. I see life batteries on ebay and over at hobbyking and a few other places for under $10. Whats the deal with these? My lipo in my dx8 is nearing death and I would like to avoid spending a ton of money on some tx packs while replacing the 8's lipo and getting a pack for the 9x all in one swing.

Any info you kind people have would be much appreciated!
piercethesky is offline  
  Reply With Quote
Old 08-07-2012, 01:33 AM   #2
rcers
Community Moderator
 
rcers's Avatar
 
Join Date: Jul 2005
Location: Trophy Club TX
Posts: 6,201
View rcers's Gallery57
Thanked 502 Times in 492 Posts
Awards Showcase

WAA-08 Pilot 
iTrader: (4)
Friends: (9)
Default

LiFe is NOT what you want for the DX8. You can just buy any cheapo 2 cell LiPo for that. Don't get the Horizon version too much $$.

The joy of LiFe is their lower voltage. So for a transmitter that uses 8 NiCad/NiMh cells 3s LiPo is really over voltage (12.6v) whereas the 3s LiFe is around 9.9v in use. So it is not as hard on the voltage regulator yet still high enough that the TX does not think the voltage is too low.

Mike
rcers is offline  
  Reply With Quote
Old 08-07-2012, 02:41 AM   #3
piercethesky
Member
 
Join Date: Aug 2012
Posts: 21
Thanked 2 Times in 2 Posts
iTrader: (0)
Friends: (0)
Default

Originally Posted by rcers View Post
LiFe is NOT what you want for the DX8. You can just buy any cheapo 2 cell LiPo for that. Don't get the Horizon version too much $$.

The joy of LiFe is their lower voltage. So for a transmitter that uses 8 NiCad/NiMh cells 3s LiPo is really over voltage (12.6v) whereas the 3s LiFe is around 9.9v in use. So it is not as hard on the voltage regulator yet still high enough that the TX does not think the voltage is too low.

Mike
Thanks Mike Wish I would have done some research on the dx8 lipo packs before all the local guys told me thats what they use. First time around I just plumped the cash down without thinking twice about it and as you can see, I am thinking twice this time around. So do you think the life will be ok in the 9x? I am honestly just considering selling my dx8, as a good friend just used his smartie parts to load up some custom programimg on my turnigy and the thing is quite awesome. Wish horizon still sold just the dsm2 module without the receiver. Anways, back to the tx/life. Is there a reason it wouldnt work with the 9x? I am using rechargeable nimh aa's in there and they seem to be on the way out as well. The cost of 8 of those is almost double what a cheap life pack is. Sorry for the long page, just really curious here.

Off to research some lipos for the dx8 so I can convince myself to keep it!
piercethesky is offline  
  Reply With Quote
Old 08-07-2012, 04:23 AM   #4
pmullen503
Member
 
Join Date: Mar 2011
Posts: 850
Thanked 71 Times in 70 Posts
Awards Showcase

Scratchbuilders Award 
iTrader: (0)
Friends: (3)
Default

There are two things to consider. What the radio needs and what the module needs. On the 9x, the radio internally runs on 3.3v. The internal 5v VR is primarily there to step down the voltage for the 3.3v VR that runs the radio.

The module on the 9x runs off of Vbat (straight battery voltage). Most 2.4G modules run on 3.3V and have linear VRs that waste excess voltage as heat. So it makes sense to use a lower voltage battery to let the VRs run cooler. The caveat here is that older FM modules need a higher voltage so if you still use those, check their requirements.

Lot's of folks run 2s Life on the 9x with no problem. There is a potential issue with the drop out voltage on the stock 5v regulator. The nominal drop out voltage is high (over 1v IIRC) and the range of the regulator drop out voltage is great enough that there could be a problem on 2s Life if you run it too low for a small percentage of radios. Best to test if you go with 2s life.

A 2s lipo or a 3s life both work fine (that's what I use). Life is more tolerant of over discharge and being stored at full charge than lipo. Life has lower fire risk too.

The most important thing on the 9x (or any radio) is to get or add the right connector so there is no chance of reversing polarity.

It's never too late to have a happy childhood.
pmullen503 is offline  
  Reply With Quote
Old 08-07-2012, 04:40 AM   #5
piercethesky
Member
 
Join Date: Aug 2012
Posts: 21
Thanked 2 Times in 2 Posts
iTrader: (0)
Friends: (0)
Default

Thanks for all the help/info guys. Its very much appreciated! If I post up a link to a couple do you mind taking a look? I have read up on the main two I am looking at but would like an actual real time opinion from someone with experience.
piercethesky is offline  
  Reply With Quote
Old 08-07-2012, 04:52 AM   #6
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,066
Thanked 698 Times in 680 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by piercethesky View Post
I recently noticed life batteries being advertised for use in a transmitter. I have been around for a while but have never known anyone personally who has first hand experience with them. I am currently using my dx8 and also have been using my turnigy 9x a bit more now that I finally have it modded.

Now, I went the lipo route with the dx8 and that was a small fortune all by itself. I see life batteries on ebay and over at hobbyking and a few other places for under $10. Whats the deal with these? My lipo in my dx8 is nearing death and I would like to avoid spending a ton of money on some tx packs while replacing the 8's lipo and getting a pack for the 9x all in one swing.

Any info you kind people have would be much appreciated!
A little caution here.

I just bought a brand new DX8 with DSMX software. This transmitter uses a four cell 2000 Mah Nih battery. Might be old school, but IMHO, those Nih cells work just fine with the constant load placed on them with transmitters.

Reading the manual, it indicates it can be programmed for either LiPo or Nih batteries. Nothing indicated about LiFe types.

As for me, it don't make a lot of sense to take a $350 transmitter, and put a cheap $10 LiPo or LiFe battery in it.

(Again, methinks those who have a transmitter issue shutting down with that $10 battery might be blaming it on Spektrum, and not the $10 battery.)

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is offline  
  Reply With Quote
Old 08-07-2012, 03:37 PM   #7
nidly
Member
 
Join Date: Apr 2012
Posts: 130
Thanked 6 Times in 6 Posts
iTrader: (0)
Friends: (0)
Default

I just started using the cheap LIFE pack in my 9x. It's going to be a-ok , but it's only 1500 mah. It fits nicely , is lightweight , and the beeper (stock firmware) is just about right at 9 volts. Watch some of the 9x voltmeters are off quite a bit (reading lower than actual)
nidly is offline  
  Reply With Quote
Old 08-07-2012, 04:56 PM   #8
Murocflyer
WAA-08 Pilot #1
 
Murocflyer's Avatar
 
Join Date: Mar 2007
Location: Edwards AFB, CA
Posts: 6,989
Thanked 311 Times in 294 Posts
Awards Showcase

WAA-08 Pilot  Globetrotter Pilot  AV Contest  AP Contest Winner 
iTrader: (8)
Friends: (0)
Default

Why bother with using a LiPo in your Tx? I use Eneloop AA rechargeble batteries in my Tx and I can charge them from the OEM charger and plug. And I don't ever have to worry about low voltage.

Is using a LiPo something I need to be doing? Am I missing something?

Thanks,

Frank

Let's Help Newcomers! << Click Here
Murocflyer is offline  
  Reply With Quote
Old 08-07-2012, 05:01 PM   #9
piercethesky
Member
 
Join Date: Aug 2012
Posts: 21
Thanked 2 Times in 2 Posts
iTrader: (0)
Friends: (0)
Default

Had a good friend on another site site offer me this pack: http://www.hobbyking.com/hobbyking/s...dProduct=17955

$8 new in the package shipped to my door

Thanks Matthew!

Is this going to be a good fit for the turnigy 9x?
piercethesky is offline  
  Reply With Quote
Old 08-07-2012, 05:04 PM   #10
rcers
Community Moderator
 
rcers's Avatar
 
Join Date: Jul 2005
Location: Trophy Club TX
Posts: 6,201
View rcers's Gallery57
Thanked 502 Times in 492 Posts
Awards Showcase

WAA-08 Pilot 
iTrader: (4)
Friends: (9)
Default

Originally Posted by Murocflyer View Post
Why bother with using a LiPo in your Tx? I use Eneloop AA rechargeble batteries in my Tx and I can charge them from the OEM charger and plug. And I don't ever have to worry about low voltage.

Is using a LiPo something I need to be doing? Am I missing something?

Thanks,

Frank
I strongly prefer the Eneloops as well for the reasons you mention. Cost is the big item. I went with a LiPo in my DX7 many years ago - it is cheap and works well (I don't charge it to full capacity to keep the voltage down).

I use a LiPo in the Aurora 9 as it supports it natively. It is lighter with the pack and the 2500 mAh capacity keeps me going for almost a full month of flying.

However at the end of the day Eneloops are simply hard to beat (other than cost).

Mike
rcers is offline  
  Reply With Quote
Old 08-07-2012, 05:28 PM   #11
nidly
Member
 
Join Date: Apr 2012
Posts: 130
Thanked 6 Times in 6 Posts
iTrader: (0)
Friends: (0)
Default

Originally Posted by piercethesky View Post
Had a good friend on another site site offer me this pack: http://www.hobbyking.com/hobbyking/s...dProduct=17955

$8 new in the package shipped to my door

Thanks Matthew!

Is this going to be a good fit for the turnigy 9x?
Yes, that's fine. It's a good fit and works fine with even the stock firmware.

I also prefer LSD cells in my TX and that's what I used to use , but the 9x is very problematic with those cells because of their slightly larger size. I use all 9x transmitters so I can't really use the LSD AA cells like I wanted too. I'll just use them in my trainer transmitters cuz they work fine. The trouble is in the stock battery holder on the 9x. It's made for smaller diameter cells. A nice shrinkwrapped set of 8 AA would be a nice set-up too.

My next 9x is going to have a lipo 2650 mah , just waiting for the LSD to go dead.
nidly is offline  
  Reply With Quote
Old 08-07-2012, 08:31 PM   #12
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,066
Thanked 698 Times in 680 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by rcers View Post
I strongly prefer the Eneloops as well for the reasons you mention.
Mike

Put me down for another vote for the Eneloop cells. They really do hold their charge for many months. I use 8 of them in a rotation on my Canon DX20IS camera. Works very well.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is offline  
  Reply With Quote
Old 08-18-2012, 12:10 PM   #13
bossee
New Member
 
Join Date: Jan 2009
Posts: 7
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

LiFe is OK to charge while the battery is inside the transmitter but LiPo should not be in transmitter while charging beacuse of the risk of fire (always charge outside transmitter in that case and not unattended).

/Bo
bossee is offline  
  Reply With Quote
Old 08-19-2012, 01:03 AM   #14
nidly
Member
 
Join Date: Apr 2012
Posts: 130
Thanked 6 Times in 6 Posts
iTrader: (0)
Friends: (0)
Default

A question specifically for the 9x TX.

Would the radio pull more current at a higher battery voltage? I think not , but wanted to make sure.
nidly is offline  
  Reply With Quote
Old 08-19-2012, 01:07 AM   #15
kyleservicetech
Dennis V
 
kyleservicetech's Avatar
 
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,066
Thanked 698 Times in 680 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

Outstanding Contributor Award  3kW  2kW  100mph Speed Demon 
iTrader: (1)
Friends: (20)
Default

Originally Posted by nidly View Post
A question specifically for the 9x TX.

Would the radio pull more current at a higher battery voltage? I think not , but wanted to make sure.
That all depends on whether the 9X transmitter has a voltage regulator in it. If it uses a linear voltage regulator, the current drain would remain pretty much the same at a higher voltage. If it uses a switching power supply type of voltage regulator, the current drain will likely drop at higher voltage.

If it does not use a voltage regulator, good question.

DennyV
Retired and the days are just too short, busier than ever!
kyleservicetech is offline  
  Reply With Quote
Old 08-19-2012, 01:25 AM   #16
nidly
Member
 
Join Date: Apr 2012
Posts: 130
Thanked 6 Times in 6 Posts
iTrader: (0)
Friends: (0)
Default

I just happened to be reading "There is a little confusion about the best 2S vs 3S better battery for the 9X. If conceptually it is true that a bigger dropout voltage between input and output leads in a bigger heat dissipation, the 7805 regulator has been designed to give the best performances with a differential voltage between input and output of about 5 to 10V. With the 7,5V (from 6V depending on the model) minimum input required voltage (2,5V of differential dropout voltage between input and output for 7805) the output peak current can not be achieved (the regulator canīt work at full dynamic range). In fact the factory testings of the LM7805 are done with a typical input voltage of 10V. Following this lines, and assuming that the input regulator is a 78xx, a 3S Lipo battery should be a better candidate than 2S to power the turnigy 9X. You can check the Peak Output Current Vs differential input-output voltage characteristic in the figure of page 21 of the attached datasheet or the Droupout voltage characteristic googleing "7805".

from this site http://eastbay-rc.blogspot.com/2011/...-9x-radio.html

Can you tell? I can't. I do see your point though. A switcher will be more efficient when using higher voltage? No waste , right?
nidly is offline  
  Reply With Quote
Reply

  WattFlyer RC Electric Flight Forums - Discuss radio control eflight > R/C Electric Power - Batteries, Chargers, ESCs and More > Batteries & Chargers

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
store Life batteries charged? cliffh Batteries & Chargers 4 08-02-2012 03:22 AM
1s Lipo batteries for Parkzone Mustang won't hold charge Captainchris Batteries & Chargers 4 09-30-2011 10:16 PM
Anyone using LiFe batteries for their receivers? firemanbill Batteries & Chargers 36 08-27-2011 03:07 PM


All times are GMT +1. The time now is 05:09 PM.


Powered by: vBulletin
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ

Charities we support Select: Yorkie Rescue  ::  Crohn's & Colitis Foundation



Page generated in 0.61886 seconds with 49 queries