How do I do dual batteries?

[GremlinX]

I want to setup redundant batts in this big Extra I am working on. I can't afford to keep spending money after money after money on this plane while saving up for private pilots certificate! I could have $4400 in this thing. Now, as for what I have. I have luck building my own packs so far. They can push about 8 -10 amps bursting. They are 2500 mah AA packs. I run 6 volt setups on everything. My question to you guys is this:
How can I take 2 2500 mah packs and do dual batteries? I do not have dual Rx's and wont on this plane. On the next "biggun", I'll spring for the whole Fromeco setup. Help me use what I have, Thanks guys.

[JeeUm]

Just use two packs and two switches going into different ports on the RX.

[Pale Rider]

Direct from http://www.rcbatteryclinic.com/

[Boulder]

Yep, what these guys said, you can plug the 2nd battery into any open slot. There are several redundant systems, that actually use an electronic device to utilize the dual batteries and draw from them either equally or from your main one, and only draw from the backup as needed.

I only use the system similar to Pale Rider's post, it works for me.

[GremlinX]

So, in reality, one could use a 2500 mah, and a 1200 mah lets just say. As long as the Volatage was roughly the same? I thought about doing it like this, but if a pack goes dead, or has an internal short, will it drain the other? Even though its in seperate ports? Thank you guys. I knew you'd know.

[Pale Rider]

	Quote: Originally Posted by mopar92
	if a pack goes dead, or has an internal short, will it drain the other? Even though its in seperate ports? Thank you guys. I knew you'd know.

The answer to that is yes since both packs will be connected via a common ground thru the RX. You can avoid this by getting something like the Smart Fly Bat Share. However I believe its pretty rare nowadays to see a shorted battery..Most of the time the failure is in the switch..IMO thats just introducing another possible failure point..

[Boulder]

If you plug them into two ports in the receiver, I normally use two batteries of the same capacity. In this setup the receiver draws from them equally.

Using a true redundant system, with one of the devices I spoke of earlier, the plane will draw from the 1st pack, the 2500, and only draw from the 2nd pack if needed.

So, if one of the packs dies, the other pack is there to pick up the slack.

[GremlinX]

Smart Fly ehh? I will look them up.Thanks. I was planning on same MaH, just asked for the sake of knowing.

[Pale Rider]

Smart Fly makes some good stuff..http://www.smart-fly.com/Products/BatShare/batshare.htm

Im,using Robert's Equalizer II's on my Edge and Yak..I just think its kind of defeating the purpose of dual switches/packs since now you are connecting them into a single unit..Maybe there is some kind of failsafe programmed into it

[GremlinX]

I am confused at the pricing/product differences on the Batshare... Thanks, I think I'll buy one when I know which is for me.

[GremlinX]

I think by going into 1 port, you gamble that if a pack or switch is lost, you still have power. If that port dies, so does your plane. Is this what you are telling me? Thanks.

[ben_beyer]

Call Robert tomorrow and ask him about it. I'm going to get one of the BatShare systems for my W/H Edge. If one pack shorts out or goes bad, it isolates it.

[GremlinX]

I just dont understand the prices for the top Batshare...Whats the difference?

[Pale Rider]

I believe that some have deans and heavier gauge wire...The actual unit is the same

What is interesting, that I never noticed, is that if you look at the picture there are 2 input leads AND 2 output leads!! That kind of changes things a bit..Now you have a separate lead for each pack so if 1 leads goes bad you still have the other to carry the load AND YOU DONT HAVE TO WORRY ABOUT A SHORT!

I think a call to Robert is a good idea..

[GremlinX]

I definately will call tomorrow. I like the idea of more power reserve if something shorts.
As for the price difference, on the top one...I think its a price if you buy two units!Duhhh. Its late. As for the two leads...I didnt see it either. I guess my eye thought it was shrink tub or a tag or something else.Thanks.