Thanks Bob!!

Hey looking at doing this on aan 50cc plane and trying to find out which diodes that I need. Will be using an 2 cell a123 pack. Thanks for your help.

I just bought some at Radio Shack/ 1N4007. I actually had to by a 25 piece assortment pack and I think it had 5 of the ones I needed. #276-1653. I think the pack was 2.59. Pretty cheap

I haven't read the entire thread and this may have been mentioned before. I fly a DA-150 powered Super Decathlon. The ignition is powered with a 2 cell A123 pack with no regulator. No problem in 27 flights.

http://www.******giants.com/forums/s...ad.php?t=49287

Post # 4 from DA............

Well a couple of things;

Yeah, RadioShack quit selling the 1N4007 diodes by themselves. I saw the multiple package deal but there's an electronics store in the area so I just hit them up for the appropriate part.

As for reading the whole thread, you'd have seen that some ignitions specifically the units used on the DLE engines won't live if you go over 6.0 volts, so there's the issue with reducing voltage for both A123's and 5 cell NiCD/NiMH batteries which have a similar voltage. And yes, DA has said on a number of occasions that their ignitions can be run on A123's unregulated.

Last as you can see from the above entry, posting any links to FG won't make it through the RCU servers as these folks have something against that forum.....

Thanks, I just read it. Before I ever used the A123 on the DA I contacted DA and they said it would be OK. Nice not to have to use a regulator.

I use a pair of 4600 mah A123s in the plane for the receiver and servos with a Smart Fly Power Expander. These batteries are great. I highly recommend them.

I have a question that has been in my mind for the past week or so, maybe someone can enlighten me,

I have used A123 batteries for several years now and really like them.

The DLE ignitions should not be run on voltages higher than 6.0 volts.

I have read that some people are using diodes on the A123 batteries to lowe the voltage( a diode I beleve is a one way valve with the side affect of a .7 volt drop).

My question is this: Why use a diode?? why not a resistor.

Sorry if my question is stupid, but I am a software Engineer not an Electrical Engineer.
Please help me understand, I have a DLE and would like to use an 1100 A123 on the ignition.

Thanks in advance

MR G

When usinjg a resistor the actual voltage drop will vary according to the load.

This idea that the Rcexl ignition can not handle voltages above 6 volts is just wrong. If that were true everyone would have to be using a 4.8 volt pack for ignition.

What they are saying is don't use voltages higher than you would get from a 6 volt pack. A fully charged NIMH 5 cell pack is actually about 7 volts and comes down gradually as it discharges. By the time you get to 6.0 volts the pack is almost fully discharged.

An A123 pack has 6.6 volts normally and 7.2 when fully charged. It comes down from 7.2 to 6.6 very quickly. 6,6 is well within the operating range of the Rcexl ignition as long as the ignition has a date code of 2008 or later. If your ignition was made before 2008 then stick to a 4 cell pack or use a 5 volt regulator.

TF

TF - After specific discussions with ralph at CH, that is exactly what he reccomends (to use a 4.8V pack). Any actual voltage over 6V just leads to higher power consumption and internal heat generation.

Directly from CH website
http://www.ch-ignitions.com/CHXL.html

Do what you want, but I've been using A123 batteries on ignitions for almost 3 years without a failure as long as it's the version 2 ignition.

TF

I have to agree with rctom i have a123 batteries on 4 of my planes direct to ignition and have had absolutely no issues,no regulator either. da85,dle55,2dle50's, TMM106. On my new pilot rc 35% extra i am using the balance port from one of my a123 batteries to run the ignition. Very simple and no added weight. Thanks for the suggestion Tom.

I have been trying out an A123 direct to the ignition on my DLE30 and have about 30 flights now; so far no problems and I know of at least a couple of guys over here in the UK doing the same - whether it will last as long who knows????

Send me a SASE and I will send you a Diode 1N007 with heat shrink and solder if you need it. No Charge.
BCCHI 3420 Chandelle Blvd ,Riverton Wy.82501

Well thank you very much for the offer but I got the appropriate diode from the local electronics store.

Always heard good things about you guys and trust me, if I get any ignition problems I know where to send 'em..