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Redwing RC life battery.

Mort2488

New to GSN!
I just bought a 2100 mah life bettery from redwing RC. It's got the Deans plug and the JR plug. Is the JR plug used for charging or can it be used to plug into the receiver?
 

TimP

GSN Sponsor Tier 1
You can use either for charging. The reason we set it up this way is so you can have either output type to your components.

Also, having two plugs let's you use a single battery for both RX and IG. Many people these days like to keep it simple in 30cc and even 50cc and do a one battery set up
 
Just checking - I'm running a Y-cable from the battery JR plug to the Rx and the opto kill switch. Did a bench test and both are getting power.

Any concerns?
 

Mort2488

New to GSN!
Charging

Do the same rules apply when charging a life battery that apply to lipos? Is charging at 1C (2.1 amps for a 2100 mah) safe?
 

TimP

GSN Sponsor Tier 1
Hey Skyraider

You should be fine. The only concern is that the JR wire does not deliver as many amps as the Dean wire (typically about 16 g. vs 22g)

you may be better getting a DEANS to JR style so you can have 2 leads coming STRAIGHT from the battery. Rather than one that is then split
We have them here: http://www.redwingrc.com/index.php?...nid=UssVUxfjeNdo7cUtH,1621&keyword=dean+to+jr
both of these will work. The DEAN to JR will go from a 16g to 22 wire/22 wire so you will have plenty of amperage to both of those

Mort:
these Lifes' you can charge pretty easily at a 5c rate! That is one advantage to LiFe is they can handle a MUCH larger C rate. 1-5 should be fine. that would be 10amps for a 2000mah... so most charges can really only do about 2.5 X (5amps). so you are fine at MAX setting!
 

3dNater

3DRCF Regional Ambassador
That configuration for a single battery has me really concerned because there is a good chance your rx power is going to get dirty ignition noise. Your rx probably won't care but your servos might. I put a 30cc plane in the dirt last year because my servos went nuts. I had a setup with a single battery and an rcexl optokill that came with my engine. I changed it to an ibec that gets power from the rx and isolates the noise and have not had an issue since. An optokill usually does not make a good buffer for ignition noise.

I am also worried about a single Jr plug to power your rx. If you have enough channels I highly recommend getting power to the rx bus from at least two Jr plugs. On my last 30cc build I just soldered up a y-harness from a dean's connection. I'm sure the one [MENTION=2470]RedwingRC[/MENTION] linked will work great.
 

TimP

GSN Sponsor Tier 1
Hi 3DNater

I think your concerns are justified, but not always a concern.

Here's the thing - of both options you have a couple concerns

Option 1) goes with a battery for RX and one for IG.
Problems:
2 batteries to remember to charge
2 batteries to fail (if EITHER fails your plane still likely crashes)

Pros:
Likely isolates noise from engine, however we have EVEN seen with 2.4, vibrations from the engine (without ANY electrical connection) affect the RX. Unlikely but could happen

2) Single battery:
Pros:
One battery to worry about and maintain properly

Cons: if it fails your plane goes down (similar to the above, it only takes one to fail)
Possible engine noise

We have found that if you TEST your RX in the following way we have NEVER experienced noise in flight.
Use your test button (usually limits signal so you can move about 60 ft. or so away before the RX stops responding cleanly). Test with engine OFF.

At the EXACT point it stopped working with engine off now test with engine ON (PLANE FULLY RESTRAINTED!)
IF it starts acting funny or stops responding SOONER than do NOT fly! If it fails to respond at the same point the noise is not affecting signal. Test several times

REALITY:
there are MANY MANY ways you can set up your system. I know guys will use power boxes and 2 RX's and more to try to create redundancy. But with EACH piece you add you add complexity and possible failure points.

It is up to the individual to decide what is the best fit for them.

Speaking of power boxes, I think the simplest way to add some redundancy without a lot of complexity is our Power board - specifically the black unit.

Reason being, you can hook up 2 batteries:
they draw evenly (balance as they draw)
also protect against SHORT circuit. this is a biggie. If you go with 2 batteries but do not have short circuit protection and one shorts your plane goes down almost instantly.

Anyway, there's a lot to cover on this subject. Maybe we'll make a video on it one day
 

vegasking

70cc twin V2
I make up pigtails like this for my 30cc and bigger for my Futaba recievers. Two J-Plugs for 30cc-70cc, Three for 100cc+.

10942843_998764350136998_660375987_n.jpg
 

3dNater

3DRCF Regional Ambassador
Thanks for the reply [MENTION=2470]RedwingRC[/MENTION]. Let me clarify what I see as an issue.

An opt kill switch is not designed to isolate the battery from noise. An ibec is. I am simply recommending that the optokill be replaced with an ibec. I have no issues with a single battery setup for 30cc. I run mine that way.

As far as the noise test you recommend... I did that on my setup and still ended up with a funky chicken servo situation. I am not saying all servos are susceptible but the ones I was using were. I tested my setup thoroughly on the ground without any issues. I think there was a certain rpm where the interference from the ignition affected the servos and I couldn't tell you what throttle position that occurred at. I am using an rcexl ibec that looks just like their optokill except it only has one lead on the input side that plugs into the rx. It is designed to isolate the rx from ignition noise, thereby protecting your servos from interference. The tech-aero is also proven to be solid.

Recap: I am not arguing for more components or fail points.

An optokill switch is not designed for a single battery setup.

An ibec gets power from the rx and does isolate the rx from noise.
 
Last edited by a moderator:

TimP

GSN Sponsor Tier 1
Yep Agreed! I meant to mention that but yes having an noise isolation component is NOT a bad idea! :)

I meant to reply that your idea is sound. Some guys will not feel they need it, and some will like the idea
 
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