BadAzzMaxx

Thanks for the link.

Will contact RCexl tonight also to see what is going on with them.

Milton

jstanton

My Feedback: (14)

Milton,

Keep use up what Rcel says if you contact someone tonight. I am going to be calling VV tomorrow and find out what they have to say.

BadAzzMaxx

Will do.

Milton

Howard

My Feedback: (55)

I began using LiFe4 about 3 years ago and now use nothing else. Because I was not aware that WrongwayRC had the voltage dropping reversed biased diodes already built I made my own from two 1N4007 diodes in series soldered into a servo extension. I think what I am doing is in sync with about 95% of what I am reading in the previous posts in this thread. I use 2300 mah 2S1P packs the switches sold by ED which enables balanced charging through the switch using an FMA charger. The ED switch has twin redundant leads into and out of the switch. Several posts in this thread indicate that they are using a single LiFe4 battery to power both the receiver and the ignition system. Their ignition system power taps off of the receiver and may or may not go through an IBEC or an optical isolator. I was surprised that there was not a tidal wave of nay sayers responding all was silent. Can I interpret the silence to mean that using a single LiFe4 battery to supply both the ignition and the flight control system is now an acceptable practice and not worry about ignition noise when using the same battery? I think Barracuda said that is how he has rigged the new H9 AgWagon for his review.

Howard

a1pcfixer

My Feedback: (7)

Many are starting to go with single A123/LiFe for both on smaller models. But many still use separate batteries for ign & servos on bigger stuff, like 50cc and up. A 2S1P 1100 A123/LiFe for ign, and a 2S1P 2300 (or two) for servos.

Just depends on what YOU think is good for your model(s).
Simple is good too, like a 4 cell 1500mAh NimH/NiCad for the ign.

SpinnerRow

I use a single LiFe4 battery for receiver and ignition but the power doesn't come directly from the receiver. I have a Y-conneciton off the switch and one lead goes to the receiver and one to the Opti-kill and then to the ignition. Since everything connects to one battery, it is really apples to apples anyway. My diode(s) go(es) between the opti-kill and the ignition module. I have two planes using one diode and one using two diodes in series. Both seem to work fine. One plane has a big capacitor across the ignition module power leads and two don't. The one with the capacitor has large/powerful digital servos that can draw quite a bit of power so I put a capacitor across the ignition leads to help with sudden power requirements. Again, it flies fine with or without it.

From my own testing, one diode will pull it down to about 5.6 to 5.8 volts with a 1 amp load on it. Two diodes would pull it down below 4.8v to about 4.7 with a 1 amp load on it. So I went with one diode to be safe. I don't notice a difference in the way the engines run on each but from what I've read the ignition probably likes the 4.7v better than 5.8v. The higher the voltage, the more power the ignition module requires.

davei

My Feedback: (56)

I run several planes with Wike battery eliminator. 20cc and 50cc. This allows one battery for both ignition and rcvr/servo power. It also provides ignition shutoff from the xmtr. The older Wike units were for 4cell nicad/mimh OR for lithium. The new ones run on almost any battery voltage( I run 2 cell 123s) I'm very happy with them. Dave I

BarracudaHockey

My Feedback: (11)

On my 50cc planes, I run one 2300 A123 pack with two leads.

One to a HD switch then to the reciever.
One to a HD switch, to a diode, then to the ignition.

The Hangar 9 Pawnee review plane got two 2300 packs. One directly to the power safe reciever. One with one lead to the power safe rx, one lead to a HD switch, then diode, then ignition.

After 5 flights the Rx only pack was at 75% and the rx/ign pack was at 67%

jstanton

My Feedback: (14)

I just got off the ph with Tim at VV and they do have newer RCEXL ignition kill switch with BEC in stock that regulates the voltage from an A123/Life4 battery down to 6v before it goes into the ignition. They tested them over the Holidaysand he said they work like a charm on a DLE ignition. The cost is 34.95 and I ordered 3. I will still tested them myself before I go flying with them

raydar

Had a look into this and on the version 1.3 opto kill switch there is indeed a small section on the instructions describing how to soilder the circuit board so that if you wish you can draw power from the reciever only and do away with the ignition battery lead alltogether. Add a diode between the opto kill and ignition then you have a single feed reduced voltage opto kill just like the new version.

Question is does the new version provide any more rf isolation than a modded old version or is it just marketing.

Milton posted the instructions on this thread.

a1pcfixer

My Feedback: (7)

Image you copied doesn't resize for viewing.

Better in the original;

http://www.rcuniverse.com/forum/fb.asp?m=10887903

jstanton

My Feedback: (14)

I just recieved my 3 RCEXL ignition kill switch's from VV. They look just like the older RCEXL kill switch and the instructions say they are ver 2.0. The product # on the bag they come in says they are RCEXL BEC/A-123. I will test these tonight when I get home from work and make sure they put out 6v going to the ignition. I will be using a 2500 mah 6.6v Life4 battery

jstanton

My Feedback: (14)

I hope I am doing something wrong on testing these new RCXEL Kill switch with BEC. I have the new RCEXL BEC/A123 kill switch and I am try to test them to make sure they indeed drop the voltage from my Life4 6.6v batteries down to 6v. I have the Life4 battery pluged into a HD switch, from there the switch is pluged into my JR reviever. I then have the side of the kill switch that says reciever pluged into my JR reciever. I have the the red plug of the kill switch that says out pluged into a voltmeter. When I turn on the power switch I get nothing on my meter at all.[:@] If I unplug the kill switch from the reciever and take a reading from the reiever and I read 6.8v. So I know I am good coming from the reciever into the RCEXL kill switch. Is this a good way to test the RXCEXL Kill switch with BEC or am I doing it wrong I think I my have a bad kill switch but I am not really sure.

a1pcfixer

My Feedback: (7)

Which port on the rcv?
If the GEAR ch/port, then you'd need to switch it ON, say flip/toggle it the other direction on the tx.

I'm a Futaba guy, so maybe a JR person can get more detailed info.

jstanton

My Feedback: (14)

I tried different ports and I just tried pluging the RCEXL Kill switch right into the HD power switch and I still get nothing. Maybe I have a bad RCEXL Kill switch[:@] I just want to make sure this is an OK method of testing the RCEXL Kill switch? I am afraid to try another one just is case what I am doing is killing the RCEXL Kill Switch with BEC.[]

jstanton

My Feedback: (14)

OK I found out that I had the RCEXL pluged into a port on the JR reciever that was in the off position. I moved the port to the on position and now I am getiing 6.26v coming out of the RCEXL Kill switch without a load on it. My Life4 battery is outting out 6.8v so the now RCEXL Kill switch with BEC model # RCEXL BEC/A123 does drop the voltage by at leats .5v but I think I will put a diode in line just to be safe. That should drop it another .7v so it should be at 5.7v at the ignition I think I will be happy with this setup

bcchi

I thought I was wrong once but found out I was mistaken.
Youll never no how little I really care.
BCCHI.
Will send hall sensors and other things first of week.

raydar

Would be nice to see the inside of the switch to see if it is just a vv inhouse bodge job that consists of a diode soildered in and possibly the opto isolation compromised or if i is a new factory design with areal bec,would be keen to find out before I spent money on a product I can mod myself.
If it is a genuine factory mod with full isolation it is a good step forward.

a1pcfixer

My Feedback: (7)

Aha! Gota have the switch ON

If you have a H9 or Futaba load tester it would most likely be at or just below 6.0v. as is.
But dropping down to 5.3v. is not going to do any harm, after all ya only need 4.8v. for long ign life.



In the fwiw dept; for every servo connector extension we daisy chain, you'll find an average of 0.1v drop.
Diasy chain a series of extensions together and for each added one check the voltage drop.

The 6.2 you got might be closer to 6.1 or less AT the ign module itself.
Do a LOAD test!

captinjohn

Guys....be sure and thank a1pcfixer for his help he gives. It takes time for him to reply. He has good advice, like top notch. So I thank him for sure. Best Regards Capt,n

jstanton

My Feedback: (14)

Jim,

Thanks for the info on the Hanger 9 load tester. I think I'll pick one up this week. To do a load test to imulate an ignition do I set it up for a 1 amp load or should t be a little higher?

a1pcfixer

My Feedback: (7)

The H-9 load tester has settings of .5/1.0/2.0 amp loads.
The lowest is all you'd need, but remember LiFe/A123's have what I'd call a surface charge when first off the charger, much like car/truck batteries.
Exercise your servos for a minute and those batteries should drop right down to their nominal state of 6.6v.

That & other similar load testers are NOT for testing LiFe/A123 batteries.

For LiFe/A123's you'd fly once, recharge and check how many milliamps put back in......then do 3 flights, and do same again.
Average it out, and you'll know how many flights you can fly before needing to recharge. Might be 3, or 4, or 5, only YOU can calculate from your flying style & how equipped how many flights it will last.

LiFe/A123's also improve in capacity ever so slightly with use. An A123-2S1P rated for 2300mAh might only show say about 2180mAh in the first few discharge/recharge cycles, but after a dozen or so cycles it'll be up closer to 2270-2300mAh.

My own personal choice would be to NOT drain more than 70-75% before recharging them. To each their own.

a1pcfixer

My Feedback: (7)

Cap't

Thanks for the kind praise, but be aware I sometimes miss hitting that nail on the head......and I have swell fingers to prove it!

jstanton

My Feedback: (14)

Jim,

Thanks for ther advice on the Life4 batteries and the Hanger 9 load tester. I'll be testing everything with the Load Tester this week.

acdii

I just picked up a 4 Amp 5V voltage regulator for $11 at a swap meet. Goes between the switch and ign module.  It can handle inputs of up to 26V. I have a spare 3S 15mah Lipo laying around that would be perfect for this.