Ignition Battery Types
 

Not a troll, guys... but getting back into gas motors after a break..... noting that nearly NOBODY sells NiCad batteries anymore. SO - what are we supposed to use for the ignition modules? Had always heard NiMh weren't very good, and I need a *lot* of convincing to go Li Po....

So - what options are out there?

RE: Ignition Battery Types
 

NiMH work fine on my gassers. I use 2700mAH capacity 4-cell. Smaller cells may not be able to deliver the current. The pack needs to put out about 800 mA of current at full throttle on a twin, specifics depend on the brand of ignition.

RE: Ignition Battery Types
 

Radical RC and NoBS batteries have all the Nicads or Nimh batteries you could every want. :D

http://radicalrc.secure-mall.com/sho...=234932&cat=1&

http://www.hangtimes.com/nobsbatteries.html

RE: Ignition Battery Types
 

The days that NiMH batteries were too sensitive are long gone. Many fliers have set up very reliable systems with them.

RE: Ignition Battery Types
 

My experience with NIMH batteries in laptops is that they were dead within a year if I used them or not. Then they cost a fortune to replace.
I have NIcds in drill motors that are more than 10 years old and still are useful.
I use NICDs. I have no trouble buying new ones.

RE: Ignition Battery Types
 

NiMH are more temperature sensitive than NiCds, especially low temp, and more sensitive to shock and vibration. Of course, they are nowhere near as sensitive to vibration as LiPoly, which is, in my opinion, simply foolhardy in a gas engine plane.

For what it's worth - just another guy's opinion - when I am mounting an ignition pack near the firewall, and hence, near some vibration, I use Sanyo 4.8v A-sized (not AA) packs in the 1200-1400 mah range. I don't feel the slight weight gain (2 oz vs NiMH) is very noticeable in larger gas planes, but the increased reliablity makes me feel better. Disclaimer - I am not a competition pilot. To those guys, perhaps 2 oz matters.

RE: Ignition Battery Types
 

If you use NiMH use a big enough pack so that the small voltage drop will not be noticed by the ignition pack. Personally I use LiION (Not LiPo's) through a 6V regulator and they work fine. I also use them (2200 mah) as flight packs. Although not essential, the huge advantage is that once you charge them they stay charged (for at least a year or two anyway). I charge everything when I get back from flying and you always know that you can go flying at any time between now and 2008 and be the batteries will be ready to go. I also use 3 of the LION cells in my transmitter - 12.4V when freshly charged but it works just fine. Same advantage.

RE: Ignition Battery Types
 

For what its worth I've had a NIMH mounted as close to the engine a (50cc) as possible for CG for 2 years with no issues whatsoever, still gives off full rating amps. Actually the receiver bettery is right on top of it as well. I am pretty sure the statement of NIMH are not as good as NICD is only true in high drain applications, like running a high drain electric motor. They are just not as good at giving off their full capacity under a high load, so a greater voltage drop will happen. With a 32oz tank I can fly for what seems like ever. Typically i fly 4 flights around 15 minutes before I even start checking the voltage. At that point it is still good right in the middle of the white zone with your typical needle type meter with a 50ma load on it. I am using a 1400 mah Hydramax (tower hobbies) NIMH. Most of the flight would average out to half throttle.

RE: Ignition Battery Types
 

There is a new generation of NiMh out that aren't as finicky as the old ones, plus they put out massive current. Just took time for the tech to mature.

My favorite pack by far (of either NiCd or NiMh) is the 1950mAh that No BS Batteries sells. It is a compact pack that has VERY LITTLE internal resistance... I get almost no voltage drop under load. It is capable of putting out 40 amps in an A-sized cell pack!!! Awesome!!! I use them on all my ignitions. I still use LiIon on the RXs though... love those things.

BTW... all batteries, including NiCds, go bad with time... the seperator breaks down. The more cells in series the faster it happens... hence I replace my TX packs every 2 years whether they need it or not. Any plane I care about gets replaced every 2 years as well... one pack at a time to prevent a bad batch of packs from taking the plane down.

RE: Ignition Battery Types
 

In the 50 years since I started using NICDs I have never seen or heard of an in flight failure of a NICD battery that was properly charged. I was the Kraft repair rep. for the Seattle area from 1970-75. At that time I saw a lot of bad batteries. All from sitting for a long period of not being charged or the failure of the cell interconnecting wires.
Currently all of my batteries except one are more than 4 years old. They work fine and I have complete confidence in them.

RE: Ignition Battery Types
 

The latest NIMH are simply terrific.
Iam comfortable using an 4.8 V 900ma pack on ignition (KANN)
I also use a KANN 900ma 6v pack for the model-on smaller models
Why?
The output of these things can be used for welding!
The new Sanyos -the same
I flew my Showtime 4D using the 6V pack last wekend - servos are 9411 and 8411 digitals
total consumption after one flight -200 ma and the servos really run fast
instant flick maneuvers lots of rudder wiggling during verticals etc..
I really am pleased with the performanceof the new small NIMH
cheap and simple and reliable
I also swapped in a new 1500 ma nimh pack into my 9303 Tx -runs all day long -
No new chargers reqd and I can charge em with any modern nicad /Nimh fast charging setup.
For twin cyls -I double the pack size for ignition and the bigger planes of course, get 2700 ma packs- which also put out high current on demand .

RE: Ignition Battery Types
 

Dick,

I have been a nicad user for as long as I can remember, however with the advent of these new high powered and low weight batteries, I am tempted to make a change. Unfortunately I know very little about the new NIMH batteries.

Is there anything one should be aware of before taking the plunge and investing in them. Do they require a special charger and do they have to be cycled like the regular nicads.


Karol

RE: Ignition Battery Types
 

Ok guys, my question is along the same lines. I'm probably going to be buying a ZDZ 80 single. I have some Fromeco Li-ions that I was going to use on the ignition with a regulator. Well, the guy I'm trading the plane for said that it's tail heavy. So, can I

A) Mount my Receiver batteries toward the ignition keeping the receiver at least 12 inches away and keep Li-ions all the way around.

B) I have a 1650maH NiMH 6volt battery that I can strap on the motor dome (it's a Comp ARF). And because it's 6V, should I use a voltage regulator or no? The battery gets up to about 7-7.2 volts when fully charged and I don't want to burn up an ignition module.

Any feedback is welcome.