I have been reading several post about using two or more battery packs for redundancy. How is this done? Is it as simple as using a Y harness or is there more involved?

Can someone explain or maybe post pictures?

Thanks,

I use this system.

The first pack connects through a switch to the receiver in the normal way.

The second pack connects via a second switch and gets plugged into any spare port in the receiver.

I use this system because I want dual switches (switch failure has lost me more models than battery failure).

Hope this helps.

Simon.

If you don't have any more free outlets on the receiver, you can use a Y harness and plug a servo and a battery.

ccdave,
The Y-harness would in fact allow you to have two batteries. But most people will also want two switches in case the switch fails. The second battery/switch is identical to the first and is plugged into any extra receiver slot. This is most often seen on larger high $$$ planes where the extra weight and money isn't an issue.

Personally, I feel there are about 4872 other reasons that are more likely to make your plane crash. I use one battery.

Tom

I was at the field over the weekend and watched as one of our more experienced pilots hovered his 60 sized heli in front of the pits. Ever so slowly the heli leaned to the right and continued into the ground. Come to find out the switch failed in mid-flight. Had he been set up with two switches/batteries this would not have happened and would have saved him about $300

Oh well... if you've got the extra battery pack I say go for it... it's only a little added weight and can save your butt in a pinch.

You could hook up the two batteries to two switches then plug the switches to a Y then in to one channel on the RX. Just a thought.

Sladerwilson,
How did you determine it was the switch and how did you determine it happened befoere the crash not durring?
Thanks,
Rick

The heli lost total and complete control. The pilot was standing 30 ft from the heli as it dove in. The heli uprighted itself once it hit the ground and continued spinning what was left of the main rotor blades. This went on for aprox 5 minutes until it gradually spun off the runway and into tall grass which bogged down the motor enough for us to cut everything off manually.

When we got the heli back to the pits we carefully checked part by part... everything worked except one thing.... the switch... there was NO POWER going to the RX. Battery was almost fully charged and all connections were tight. We direct wired the battery to the RX and magically everything came back on. All the servos worked and the RX worked without any glitches.

I understand that there is the possibility that something else could have come loose and then RE-TIGHTENED on impact but what are the odds. The switch showed no damage from the impact but yet we could not make it work no matter what we tried.

If it looks like a duck, walks like a duck and quacks like a duck... it must be a duck. That's the methodology we use.

Switches can fail just as easily as batteries can so there are different ways of creating a redundant system some are greatly more redundant then others. One method is by using one battery two switches, second is by using two batteries one switch, third would be a most often full redundant system by adding two batteries and two switches.

The first method can be setup by either a Y harness made up of plugs or solder along with heat shrink, if you want to save a Penney or two. The second method would work the same depending on how many ports open in your receiver you can use two ports for the batteries if all ports are full then you can tie both batteries together by way of Y harness or solder. Then of course the third would require an extra empty port on the receiver for the second battery.

Please note; that by using method two you can not charge both batteries through the same charge jack as both batteries have to be charged separately.


Again as I mentioned above you can make your own Y harness if you have knowledge in soldering wires together.

Blackie

I'm a little concerned here!

I have heard in the past that NiCads should not be hooked up in parallel because of their low internal resistance. If one cell is at a lower voltage than one in the other pack the higher voltage will try to drive the low voltage pack like a resister, causing a thermal runaway in both packs. All of the set ups in this post so far have set up this condition.

Any battery experts out there have some input?

MajorTomski, take a look at reds site in relation to running batteries in a parallel system.


Running batteries in a parallel system

Blackie

This only becomes an issue when charging. Never charge batteries in parallel.