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-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430

WHY can't they just come up with a controller that has external alligator clips like the old Astron one ???
6 "C" cells ?? C'mon now...who wants something that weighs that much ?
I just use my old Astron controllers from the 70's still.
Hook the alligator clips right up to my 12v Wet-Cell motorcycle battery in my R/C flight box.
VERY simple and lots of amperage to fire clusters with BARE nichrome.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

I will not answer for Estes, but simply use logic.

The average American consumer will not have a large external battery. They want something that can easily be carried to the launch field. 6 C alkaline cells are easy and simple and provide plenty of power.

The built in receptacle for the MUCH higher capacity rechargeable battery packs (NiMh or LiPo) will be perfect for those more advanced rocketeers who will be launching clusters and igniters that require more amperage.

I cannot imagine any toy company producing a product that would have you pop open your car hood and attach anything to your car battery. They would not do that in 1985 and they will not do that in 2014.

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-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430

Since the connector for an alternative battery is inside the battery compartment and is a little two-pin JST (takes the orange two-pin connectors that were popular for small electric airplane batteries a few years ago) it will take some remodeling to bring the lead outside to install a "MUCH higher capacity rechargeable battery pack". I have a long and slender ElectriFly 3s 1500 mAh LiPoly pack that I can just squeeze inside between the springs for the negative terminals of the C cells. I will be using that for my lithium-powered trials of this unit. I need to make a JST to 2-pin Deans adapter up so I can use the battery I have without changing the connector on it.

It WILL be lots lighter with this LiPoly in it.



I used mine some yesterday afternoon - easy to use, Q2G2 safe and the need to push two buttons to fire an igniter isn't at all awkward either hand held or with the controller on a table. I like that the beeper is on only when the yellow button is pressed. (Continuity is also indicated by a bright LED which comes on when the arming key is in.) So far, so good.

I need to try out the built-in cluster capability , too. For those who haven't seen it yet, each clip lead has two clips with about 9 inches of wire on each before they join in with the main lead, and the instructions show how to hook up some cluster configurations.

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Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE

What does the battery space look like?

A quick search with the assumption that the battery has to fit into a space 27mm x 50mm x 158mm (6 C batteries laid out in a row side by side) shows a few 3 cell lipos with around 3000mah that would fit in that space. The issue would be the relatively small leads for the JST connecter.

kj

What I meant by "much higher capacity rechargeable batty pack" was that those packs recommended in the instructions would be much higher capacity than the c cell alkaline batteries. The instructions say that you can fire up to 6 Solar Starters or 4 Sonic Starters with the 1000mAh LiPo pack.

Perhaps the rechargeables do not have a higher total capacity (mAh) than the C cells, but they can deliver more amperage because of their unique design and chemistry and lower internal resistance.

The 6 C cells might be the better choice for teachers and youth group leaders who are launching dozens and dozens of single motor rockets one at a time.


By the way, the instructions do not limit you to 1000 mAh for the LiPo, they list that as the MINIMUM. So, let's see what folks can cram in there with the stock connector.


.

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-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430

6 C cells next to each other. Big springs protrude from alternating sides. The alternate JST receptacle is located mid way along the top long edge (between the center two C cell locations).

__________________
-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430

Capacity is a total energy measurement of batteries very analogous to total impulse in a rocket motor. Current delivery capability, which is much more like peak thrust, is only loosely related to battery capacity, just like the peak thrust of a motor is only vaguely related to the total impulse. So if you want to discuss internal resistance (and therefore current delivery capability) do not use the term "capacity".

The little JST connector is good for 2-3A continuously at best. For short bursts (like firing a rocket) I'd be comfortable putting maybe 6-8A through it. It will be the limiting factor for the practical cluster limit of this controller when powered with something other than 6 alkaline C cells. This is my judgement is based on 30 years of electric powered RC experience.

My previously-mentioned several-year-old 1500 mAh LiPoly pack will easily deliver enough current to melt that JST connector if asked. I expect if one had such a battery inside and were foolish enough to just clip one pair of micro clips together and then push both the yellow and red buttons with the key in, that's exactly what will happen - the JST connector will melt and/or the lead will get hot enough to melt insulation and short the battery out. That would NOT be a good thing.

According to this http://media.ww2.duracell.com/media...%20Bulletin.pdf Duracell alkaline C cells have a capacity of 7.8Ah (7800 mAh). But it also gives a typical internal resistance on the order of 1 ohm which is much greater than current NiMH or LiPoly cells.

There is no way one is going to get either a NiMH or LiPoly battery into this controller with capacity anywhere near 7800 mAh without at least removing the springs that are there for the negative terminals for the C cells.

However I can certainly see fitting a lithium battery that can deliver all the current the power input connector can take. Again based on electric powered flight experience, getting a NiMH pack in there that's even 1000 mAh and six cells or more is going to be a real squeeze.

__________________
Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE

Yup. That is what I was realizing after I looked up the C cell specs myself.

It is fine for what it was designed for and the instructions are pretty clear. The limits on power are on the low end the minimum listed in the instructions and the maximum is the physical limit of what you can fit inside the compartment with those springs.

Wouold you agree that the C cells would be better for those who are looking to launch single motor rockets and a lot of them, such as teachers or youth group leaders?

__________________
-Fred Shecter NAR 20117 (L2)
Southern California Rocket Association, NAR Section 430

Sorry but this is an inccorect statement. Having used this connector on my Nicads, NiMH and Lipos over the past 15 years on my RC airplanes, you can get way more then3 Amps continous current out fo these connectors. I've run 8 to 10 Amps continous through this connnector all the time. The wire gets a little warm but it works. As for this controller, the standard dry cells work great for one Estes Igniter, and has a very short delay when using two Estes igniters. but they both fire at the same time which is the important thing. You should get at least 250 launches out of one set of new batteries. I've tested the controller with nicads, NiMH and my favorite 3-cell Lipo, ranging from 500mAh to 1300mAh. The 1300 mAh works really well, Six Solar igniters go off perfectly. I've even done 8 and 10 ingiters but there is some delay and they ALL don't go off at exactly the same time, so I would stick with 6 igniters. I'm quite sure you can do a whole lot more of the Quiest igniters. The best part of using a higher current output battery is that the igniters will draw as much current as they need and since your drawing this current for only about a second, the JST connector shouldn't get hot at all. Since I am sure someone out there is going to take this controller apart you will see that there is a 10 Amp diode in the circuit so when you install a battery in the JST connector there will be virtually NO current going across the battery connectors that the Alkaline batteries use. The diode can handle over 10 Amps for short periods of time.


John Boren