ttanner

I have a Futaba 7 channel reciever and need to add two batteries for redundancy. I have added a Yharness to my throttle port and added the second battery to that channel. Does anyone have any knowlege of this working or failling? The batteries are the same. Thanks..

karolh

What might be a better arrangement is having a seperate on/off switch for the second battery

Karol

ggraham500

My Feedback: (4)

Right, but by using a separate on/off switch, would you turn both switches "on" for flight? By using a y-harness on one channel does that make the batteries in parallel?

Thanks.

karolh

Yes

tomfiorentino

Welcome to RCU Tim!

True redundancy all around is achieved with two batteries, two switches and into two ports into the receiver (some eliminate swithces with power safe type receivers (JR) that have one soft switch at the receiver). With what you have described on the Y harness, the harness is a single failure point and a problem there knocks everything out "upstream".

If you could describe your overall setup some more some of us can probably help you out better. Usually with a two battery set up we are also trying to spread the amperage draw across separate connections thereby doubling the amps the system can take (digital servo loads etc.). You wouldn't get this with the y-harness idea either.

Anyway, tell us more about what you are setting up:

What kind of plane
How many servos, are they digital
What battery chemistry are you talking about
Is this a gasser with ignition
Etc
Etc

Thanks,
Tom

ttanner

 i don't know that this or the other post posted?  So here I go again.  I have a SBach 342 with a DLE 55 using HI Tech digital servos.  I am trying to gain redundacy by using two batties each battery is a HydriMax 4200mAh NMH to one reciever.  I have installed a miracle switch with two switches one to one battery to reciever port form switch and the other one from channel 3 on reciever to a Y ext to other battery to other switch.  thanks guys for all the feed back this community is awsome to help others like myself.  thanks again.

tomfiorentino

Ttanner,

I understand what you have done, but a "Y" to a servo and a battery is odd. I'm just not us about that part...which is what you are asking I know.

As to the rest of it though, two batteries, two switches...excellent!

Let's see if someone else chimes in on the Y part.[]

Tom

BuschBarber

My Feedback: (2)

It is perfectly normal to connect a second (redundant) battery and switch harness to a free channel port or to any channel port in a Y Harness with a servo. The battery port and all servo ports share the same power bus.

ttanner

Thanks for all the help on this issue I have bit the bullet per say and going to stick to what I have posted. Thanks to all for the help.

pdm52956

My Feedback: (1)

One comment on the switch you've decided on. There have been issues with the solder joint where the wire connects to the switch. Vibration can cause the joint to fail. I've been running that switch without problems for a couple years until this past weekend when I noticed that a wire had broken at the joint for the charge jack.

I urge you to get some shoe goo and put it around the solder joints at the wire connections on the back of the switch. It will dampen the vibration and stop the wires from breaking.

BarracudaHockey

My Feedback: (11)

IMO thats a lot of weight to tote around on a 50cc aerobat.

I'd look at getting some A123's

DougV

Amen!

Doug.

MTK

Tim,

Let me recommend that you speak with Ed Alt of Tech Aero Designs. He is a specialist of reduntant battery set-ups. Look up his website

Simply putting two batteries in parallel as you are doing is not as complete an answer as you may want. If one battery fails from a short, the other will still work your radio for a short time but will also drive to charge the other shorted battery. The shorted battery will be a large load on your good one and will drive the good one to discharge quickly.

If the one battery fails open, then it isn't as much of a problem but you will not have the redundancy you seek. Regardless, Ed will steer you properly and will likely recommend the best course of action.

We fly high end Pattern planes and most of us use redundant voltage sources for the radio specifically for that reason. Ed has designed some very good electronics that simplify the set up of redundant power

hsukaria

I have a similar setup with redundant batteries and switches. But instead of going directly to the receiver, I installed a "PowerBacker" from ElectroDynamics. It takes in 2 6-volt batteries and feeds out one connection to the receiver. The batteries are isolated from each other in case of a short. It always picks the battery with higher voltage. So, if you have 2 batteries with say 2000 mAh, then you essentially have 4000 mAh charge (that is what I have set up on mine).

Here's the link: http://www.electrodynam.com/rc/EDR-108/index.shtml

yearnin to Fly

My Feedback: (52)

I lost a plane about a year ago due to the very same failure at the wires where they connect to the miracle switch you are talking about.( the solder joints were VERY POORLY soldered ) I went back and checked out the other planes I had the miracle switch installed in and found out it WAS A MIRACLE I had not lost more planes due the JUNK miracle switches. I pulled them all out of my planes and replaced them with Jr on off switches and have never had a problem since.

Oh well lesson learned.

ttanner

  Guys I can't say enough about the help I get from this forum.  I am going to replace the miracle switch like suggested and I am adding a Battery Share which will do away with the Y harness also.  As far as the wieght I am still tail heavy.  Maybe we need to rename the miracle switch to " say a prayer switch"

ttanner

Hey guys just got my 38% extra 330s with DA150.  i have not finished it yet.  I have a few questions that I cant get a straight answer on.  I have a battery share by smart fly, it has two Inlets and two outlets.  i know one battery from switch goes to inlet 1 and the other vbattery from switch to inlet 2, my question is where does the other side go?  the outlet has two plug also i know one should go to the reciever but does both?? I look at the drawing on smart fly but no help.Any information is greatly appreciated.

BarracudaHockey

My Feedback: (11)

Yes, both outputs to the reciever. Any open port is fine, the power lines in the reciever are all on a common bus.