RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Cons for installing redundant receiver batteries ?

Reply
Old 10-18-2012, 09:43 AM
  #1
rcfun2005
Thread Starter
 
Join Date: Apr 2005
Location: Houston, TX
Posts: 139
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Cons for installing redundant receiver batteries ?


Cons installing redundant receiver batteries ? …

I was going to just run (2) Life batteries , (2) manual switches , connecting both to the receiver on (2) separate ports on the receiver.

This is going on hitec aurora 9 channel receiver in Modellbau Tornado .

Seems like a low cost solution to some redundancy .

What would be the down side to this type connections for redundancy ?

Thanks, Joe
rcfun2005 is offline  
Reply With Quote
Old 10-18-2012, 09:51 AM
  #2
BarracudaHockey
Community Moderators
 
BarracudaHockey's Avatar
 
Join Date: Jul 2003
Location: Jacksonville, FL
Posts: 21,396
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

Weight and cost are the only downsides
BarracudaHockey is online now  
Reply With Quote
Old 10-18-2012, 09:51 AM
  #3
trioval00
 
Join Date: Jul 2002
Location: wilkes barre, PA
Posts: 2,407
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

No cons from me. I have been running dual batteries for 9 years now. and I will always use dual batteries.

some of the jets I have an "Electro Dynamics Battery Backer" and some have dual output for batteries built into the receiver....



Mark
trioval00 is offline  
Reply With Quote
Old 10-18-2012, 09:57 AM
  #4
rcfun2005
Thread Starter
 
Join Date: Apr 2005
Location: Houston, TX
Posts: 139
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

good deal,

so just running batteries in parrallel is ok .

not sure any details , i just see "powerbox" comes up alot when discussing redundant batteries.

i guess it provides more features.

thanks, for the input.

Joe
rcfun2005 is offline  
Reply With Quote
Old 10-18-2012, 10:16 AM
  #5
John Redman
 
Join Date: Dec 2001
Location: Lancaster, CA IL
Posts: 2,306
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

Running two batteries into a receiver is fine. Understand that if one starts to go bad it can drain the other in no time as tehy will talk to each other. That is why the voltage regulator is a great thing. Not as much to regulate voltage but to work more like a one way check valve in the electronics world.

Only down side to two batteries is:
1) remembering to charge both batteries.
2) remembering to turn both batteries on before a flight.

Ask me how I know this.
John Redman is offline  
Reply With Quote
Old 10-18-2012, 10:37 AM
  #6
rcfun2005
Thread Starter
 
Join Date: Apr 2005
Location: Houston, TX
Posts: 139
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?


"That is why the voltage regulator is a great thing. Not as much to regulate voltage but to work more like a one way check valve in the electronics world. "

oh, i see now ... one way ck valve ... yes that would be a big benifit ..


so i presume "powerbox" is one of the solutions to providing voltage regulator.

thanks for that insight..

joe
rcfun2005 is offline  
Reply With Quote
Old 10-18-2012, 10:45 AM
  #7
speed is life
 
speed is life's Avatar
 
Join Date: May 2006
Location: Redstone, CO, USA
Posts: 330
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: John Redman
....(snip)........... Understand that if one starts to go bad it can drain the other in no time as tehy will talk to each other. a great thing.............(snip)......... Not as much to regulate voltage but to work more like a one way check valve in the electronics world.

Ask me how I know this.
not true:http://www.hangtimes.com/parallel_packs.html

There is no down side to independent parallel packs/switch/harness going into different receiver ports for redundancy (except a very small weight penalty). One does not even need a regulator if using A123's.

speed is life is offline  
Reply With Quote
Old 10-18-2012, 11:19 AM
  #8
Dr Honda
 
Dr Honda's Avatar
 
Join Date: Apr 2005
Location: Latrobe, PA
Posts: 2,214
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

As others have said... there is no "Negatives" with redundant batteries, other than weight. But... in the case of my falcon (Similar to the Tornado) I needed some weight up front to balance my heavy AMT engine. So... I have 2 NiMh 5 cell packs in it.

I'm flying JR/Spektrum and the 921 Rx has 2 battery ports. So it's easy to implement.
Dr Honda is offline  
Reply With Quote
Old 10-18-2012, 01:04 PM
  #9
wfield0455
 
wfield0455's Avatar
 
Join Date: Sep 2005
Location: Holliston, MA
Posts: 865
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

While there is nothing wrong with simply running the outputs of 2 switches directly to your receiver it is a good idea to use a battery share circuit. The battery share circuit provides isolation between the 2 packs and will prevent one pack from draining the other should it become discarded, etc. Voltage regulators, unless they are dual regulators, generally don't provide this functionality and if one regulator or battery fails they can still quickly drain the other battery as well. A couple of battery chare that I have used in the past are the Smart-Fly Battshare and the Fromeco Woverine switch. The Wolverine is a dual switch with a built in battery share circuit. It's also similarly priced to a pair of JR Heavy Duty switches so it's not particularly expensive.
wfield0455 is offline  
Reply With Quote
Old 10-18-2012, 01:13 PM
  #10
speed is life
 
speed is life's Avatar
 
Join Date: May 2006
Location: Redstone, CO, USA
Posts: 330
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: wfield0455

...............battery share circuit provides isolation between the 2 packs and will prevent one pack from draining the other should it become discarded, etc. .........
see link in post #7 This is an old wives tale - It can't happen.

speed is life is offline  
Reply With Quote
Old 10-18-2012, 01:18 PM
  #11
David Gladwin
 
David Gladwin's Avatar
 
Join Date: Feb 2002
Location: CookhamBerkshire, UNITED KINGDOM
Posts: 3,231
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: John Redman

Running two batteries into a receiver is fine. Understand that if one starts to go bad it can drain the other in no time as tehy will talk to each other.

Sorry, John thats simply not true, another urban myth !

Verification, my own exhaustive tests AND see NOBS batteries web site for the expert technical explanation.

Two batteries into a single receiver is absolutely fine, in fact anything less is potentially and unneccesarily dangerous. A single battery failure and its all over ! Best to connect them at opposite ends of the receiver bus (Kirchoff's law).

In the long run its cheaper too, as batteries can be kept in service (on condition) until showing some degradation, rather than changing every couple of years or so, its a million to one chance the second battery will fail at the same time.

Dual batteries should be mandatory for any gas turbine powered model.

Regards,

David Gladwin.





David Gladwin is offline  
Reply With Quote
Old 10-18-2012, 01:34 PM
  #12
BarracudaHockey
Community Moderators
 
BarracudaHockey's Avatar
 
Join Date: Jul 2003
Location: Jacksonville, FL
Posts: 21,396
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

Thats true, if you need the weight somewhere it could be just another benifit!

Yea, you can leave batteries for hours and they wont effect each other.
BarracudaHockey is online now  
Reply With Quote
Old 10-18-2012, 02:40 PM
  #13
erbroens
 
erbroens's Avatar
 
Join Date: Nov 2003
Location: Curitiba, Parana, BRAZIL
Posts: 4,140
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

No Cons, and I would daresay that this is one of the best things you can do to your model and our hobby.




Enrique
erbroens is offline  
Reply With Quote
Old 10-18-2012, 02:58 PM
  #14
Chris Smith
 
Chris Smith's Avatar
 
Join Date: May 2004
Location: Adams TN, Berea KY
Posts: 786
Default RE: Cons for installing redundant receiver batteries ?

Even the smallest model jet has room for two lightweight 1100 A123s and two switches. Other gadgets are swoopy, but I find in my old age less is more. All the receivers I use are designed to handle the sustained voltages of both batteries directly to the receiver.
Chris Smith is online now  
Reply With Quote
Old 10-18-2012, 03:21 PM
  #15
Dr Honda
 
Dr Honda's Avatar
 
Join Date: Apr 2005
Location: Latrobe, PA
Posts: 2,214
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: Chris Smith

Even the smallest model jet has room for two lightweight 1100 A123s and two switches. ........

I agree.







Dr Honda is offline  
Reply With Quote
Old 10-18-2012, 03:53 PM
  #16
5skyhawk172
 
5skyhawk172's Avatar
 
Join Date: Nov 2010
Location: Fort Wayne, IN
Posts: 164
Default RE: Cons for installing redundant receiver batteries ?

Not trying to hijack the thread, but I have a question.  I'm new to the turbine world and I just bought my first quart of turbine oil (aeroshell 500).  Is it correct to mix one quart to five gallons of kerosine?  Thanks,  Keith
5skyhawk172 is online now  
Reply With Quote
Old 10-18-2012, 04:02 PM
  #17
rctech2k7
 
rctech2k7's Avatar
 
Join Date: May 2009
Location: Miami, FL
Posts: 377
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

I've seen some points here when paralleling batteries. This is what happened when paralleling batteries with different charge level even for identical batteries. If one battery has higher voltage than the other the current will flow and energy is transfer to the lower battery until charge is completed or internal voltage becomes the same then batteries distribute the same power (only for identical batteries and feeder lines). This circulating current depends on the type of battery, condition and resistances, however at most level condition it's negligible due to LiFe battery properties but not all similar for NiCd...

For the OP,
There are different way for battery redundancy and yours is far good so this is only I can say based on your query:

1. You want to make sure both batteries are online but you still get the same reading when one switch or connection failed so you may turn off the first one to make sure the second one has power and turn it back on again.
2. You have a chance to leave one switch in off position since either one can power up the system, the solution is to tag both of them or any equivalent.
3. Both batteries are sharing power distribution and have the same voltage, when one run out of power the second one will have exactly the same. The condition is to fly within the safe limit of one battery and to determine the cause of failure if any.
4. Your system has far better to have chance of lost power than using single battery but it doesn't have protection if one battery becomes faulty, I believe this is the lowest chance of battery failure and almost eliminated on our latest high quality batteries.
5. Batteries can be used as balancer as well but in some cases if you're using large identical batteries that either one can powered more flying time then weight is a cons but it can be reduced by installing smaller backup battery instead of redundancy and although it has power indicator it will only work when main battery fail and enough to land the plane in one cycle unless it is recharge and with main battery power restored.
rctech2k7 is offline  
Reply With Quote
Old 10-18-2012, 04:19 PM
  #18
Dr Honda
 
Dr Honda's Avatar
 
Join Date: Apr 2005
Location: Latrobe, PA
Posts: 2,214
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: 5skyhawk172

Not trying to hijack the thread, but I have a question. I'm new to the turbine world and I just bought my first quart of turbine oil (aeroshell 500). Is it correct to mix one quart to five gallons of kerosine? Thanks, Keith

What does this have to do with batteries?? Yes... you should start your own thread or search for 2 seconds.

But... to answer your Q... Yes. That will give you 5%.
Dr Honda is offline  
Reply With Quote
Old 10-18-2012, 05:09 PM
  #19
Xairflyer
 
Xairflyer's Avatar
 
Join Date: Dec 2002
Location: Co. Donegal, IRELAND
Posts: 2,738
Default RE: Cons for installing redundant receiver batteries ?

What about two battery's of different capacitys connected to a reciever
Xairflyer is offline  
Reply With Quote
Old 10-18-2012, 05:49 PM
  #20
Dr Honda
 
Dr Honda's Avatar
 
Join Date: Apr 2005
Location: Latrobe, PA
Posts: 2,214
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?

Quote:
ORIGINAL: Xairflyer

What about two battery's of different capacitys connected to a reciever

The "Quick" answer is... that's fine, as long as they are the same voltage.



OK... here's the deal.........


If you think of a fluid... The voltage is the "pressure" of the system. So... regardless of the size of the tank (capacity of the battery) the voltage will try to balance. As the smaller "Tank" gets consumed... the pressure will start to drop, and the larger "Tank" will feed more, until the 2 pressures are balanced. (this is a pure answer)


With that said... (in the real world) if you try to mix battery types, or sizes (differences in internal resistance) then they can get out of balance. Basically... you should run 2 of the same packs with redundant batteries, especially if you aren't using any kind if isolater/regulator system.


So... yes it will work... but it's not advised.
Dr Honda is offline  
Reply With Quote
Old 10-18-2012, 06:10 PM
  #21
gooseF22
 
gooseF22's Avatar
 
Join Date: Aug 2006
Location: Fort Wayne, IN
Posts: 2,305
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: John Redman

Running two batteries into a receiver is fine. Understand that if one starts to go bad it can drain the other in no time as tehy will talk to each other. That is why the voltage regulator is a great thing. Not as much to regulate voltage but to work more like a one way check valve in the electronics world.

Only down side to two batteries is:
1) remembering to charge both batteries.
2) remembering to turn both batteries on before a flight.

Ask me how I know this.
me too..LOL.. I forgot to turn the second switch on too.. it was on a wolverine...woohoo..
gooseF22 is online now  
Reply With Quote
Old 10-18-2012, 06:12 PM
  #22
gooseF22
 
gooseF22's Avatar
 
Join Date: Aug 2006
Location: Fort Wayne, IN
Posts: 2,305
Default RE: Cons for installing redundant receiver batteries ?

deleted..
gooseF22 is online now  
Reply With Quote
Old 10-18-2012, 06:14 PM
  #23
gooseF22
 
gooseF22's Avatar
 
Join Date: Aug 2006
Location: Fort Wayne, IN
Posts: 2,305
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: 5skyhawk172

Not trying to hijack the thread, but I have a question. I'm new to the turbine world and I just bought my first quart of turbine oil (aeroshell 500). Is it correct to mix one quart to five gallons of kerosine? Thanks, Keith
Keith, PM'd you.. Im local Ft Wayne
gooseF22 is online now  
Reply With Quote
Old 10-18-2012, 06:19 PM
  #24
gooseF22
 
gooseF22's Avatar
 
Join Date: Aug 2006
Location: Fort Wayne, IN
Posts: 2,305
Default RE: Cons for installing redundant receiver batteries ?

I prefer wolverine for a switch if not using switched regulators or a Powersafe rx..
I did some of the Flight testing and bench testing of the Wolverine design.. with 4 10 am mofsets, I can tell you that thing is robust.. I ran an electric motor thru it at 40 amps twin deans in and out.
gooseF22 is online now  
Reply With Quote
Old 10-18-2012, 06:48 PM
  #25
VF84sluggo
 
VF84sluggo's Avatar
 
Join Date: Nov 2007
Location: Gulf Breeze, FL
Posts: 2,367
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Cons for installing redundant receiver batteries ?


Quote:
ORIGINAL: rcfun2005


Cons installing redundant receiver batteries ? …

I was going to just run (2) Life batteries , (2) manual switches , connecting both to the receiver on (2) separate ports on the receiver.
Joe, this exact setup has worked very well for me in my Boomer Intro. No problems at all.

VF84sluggo is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
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



All times are GMT -8. The time now is 07:54 AM.