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 Topics - General > RC Radios, Transmitters, Receivers, Servos, gyros
Register Members List Wattflyer Extras Articles Search Today's Posts Mark Forums Read Social Groups

RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

Thank you for your support (hide ads)
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 07-06-2011, 05:41 AM   #1
Super Contributor
kyleservicetech's Avatar
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,951
Thanked 774 Times in 752 Posts
Club: www.racinercclub.com (I'm the newsletter editor)
Awards Showcase

4kW  Outstanding Contributor Award  3kW  2kW 
iTrader: (1)
Friends: (21)
Default LiFe vs Nih Receiver battery tests

It's becoming well known that the 2.4 Ghz radios may be susceptable to undervoltage issues on the receiver battery supply. And, these have resulted in loss of control of the model. Spektrum did do some software updates a while back to reduce the time of "Rebooting" in case of a low battery issue. My testing on updated AR7000 receivers shows this "rebooting time" is less than a second.

IMHO, this is not a receiver issue, it's a problem with the receiver battery selected. By actual test, I've measured the peak currents pulled by all 7 Hitec 645MG in my giant scale Extra 330 model. That peak current was measured at 14 amperes, with the one millisecond peak holding feature of my Fluke 87V digital multimeter.

So, to illustrate this issue, two discharge current tests of 12 amperes were applied to a new LiFe 3200 Mah battery, and to a new 5 cell 2700 Mah Nih "AA" type receiver battery.

The attached graph, taken from my Western Mountain CBAIII battery test unit shows it all.

Take a look at the attached JPG: The 12 Amp load on the Nih battery was shut off when the voltage dropped to 3.6 VDC, a value reached in about 2 seconds. Note that those Spektrum receivers will reboot when the receiver battery voltage hits 3.2 VDC. The Nih battery test was conducted immediately after it was fully charged. The results will be worse after a few flights on the model.

Again, IMHO, the 2.4 Ghz receiver of any large model with more than 4 servos and a receiver battery should be using a higher powered receiver battery than those "AA" type units. Recommendations would be one of those LiFe types, a "Sub C" 5 cell Nih battery, or a uBEC such as Castle Creations 10 (or 20) Amp Switching Battery Elimination Circuit.

Attached Thumbnails
Click image for larger version

Name:	LiFe vs Nih battery Test.jpg
Views:	910
Size:	178.6 KB
ID:	150463  

Retired and the days are just too short, busier than ever!
kyleservicetech is offline  
  Reply With Quote

  WattFlyer RC Electric Flight Forums - Discuss radio control eflight > R/C Electric Topics - General > RC Radios, Transmitters, Receivers, Servos, gyros

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
Everything You Wanted To Know About Electric Powered Flight AEAJR Beginners 165 06-28-2017 04:22 PM
100+ MPH Club CHELLIE Hi-Performance and Sailplanes 1994 05-09-2016 03:05 AM
For Sale JR XP7202, Charger, R790UL Receiver, RX battery and switch harness bobskinner Radio Equipment For Sale & WTB 0 05-10-2011 03:43 AM
Help Weird constant beep noise when connecting the battery, esc, and motor to the receiver jbar1001 Support & Suggestions 6 02-20-2011 04:15 AM
Measuring Battery DC Resistance Procedure kyleservicetech Batteries & Chargers 0 12-12-2010 05:50 AM

All times are GMT +1. The time now is 12:37 PM.

Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ

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

Page generated in 0.15322 seconds with 64 queries