Goog 9V batteries for launching LPR and MPR

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

morlock

Well-Known Member
Joined
Jun 18, 2014
Messages
630
Reaction score
4
I'm looking for common brand good 9V batteries with high current discharge to use in LPR and MPR (Estes E launch system).

I want something that produces reliable current for my launches and is reasonably priced.

Any favorites?
 
I think we may need a bit more info on what you are looking for: are you looking for a rechargeable battery pack, the best 9V transistor battery, or any source of 9V. For example, if you don't mind using disposable batteries, six D cells will dump a lot of current quickly without causing problems (LiPos CAN overheat and catch fire when dead-shorted, which is essentially what we are doing with an igniter). If talking about transistor batteries (such as for the Quest launch controller), either Duracell or Energizer will do best - steer clear of RayOVac and other secondary brands.
 
I want a good disposable rectangle (6 cell I guess) 9V battery. I will avoid non main brands but even among the main ones maybe people have favorites or some to avoid.
 
Energizer Advanced Lithium. Bunch o' punch. Other than that, I'd go with a 9v pack made out of AAs.
 
I think when you're talking about "reliable current" a 9V battery is really pushing your luck. What kind of controller are you using?

After having bad results at a launch, I did some testing on the 9V Rayovac I had been using with the Astron launch controller (came in a launch set). I measured 1.5A when first depressed, and immediately drifting downward after that. That will not provide a satisfying experience with Estes igniters. It is possible that other brands would do better, but I don't really trust them in general for this use (unless you're using Q2G2 igniters in which case they should be fine).

After my bad experience I went way in the other direction and picked up a Pro II launch controller (not expensive at $35); loaded with 6 NiMH C batteries (which I already have in the house) it'll dump a steady 4.5A into the igniter, one after another.

I actually considered picking up a 9V NiMH rechargeable to try in my Astron, but decided it just wasn't worth it.
 
Energizer Advanced Lithium. Bunch o' punch. Other than that, I'd go with a 9v pack made out of AAs.

I never thought of trying those. They might be better than alkalines, but I'm still not sure Lithium chemistries are really designed for that sort of use (but hey if they work then go for it).

I hate using disposable batteries and have a bunch of NiMH rechargeables already lying around, so I lean towards one of those solutions. A 6-pack of NiMH AAs (to yield 7.2V) would perform extremely well, and still be small and light. I like the fact that you can always know you're going to the launch with a full charge.
 
The Estes E controller uses AAs. Duracell, Energizer or even the Costco house brand works fine there. The Estes PSII launch controller uses six C cells. Same story. NiMHs of the appropriate size will be fine as well (though most consumer NiMH C-cells are just adapted up AAs - so might not be so great there). The PSII controller also has an internal socket for the little orange JST connector, which is intended for use with a LiPoly. A 1000 mAh 3 cell battery will fit inside. This works very nicely.

The only Estes controller that uses a 9V is the little orange Astron II. There, Duracell or Energizer again are the way to go. I don't know of a viable rechargeable for that application.
 
The Estes E controller uses AAs. Duracell, Energizer or even the Costco house brand works fine there. The Estes PSII launch controller uses six C cells. Same story. NiMHs of the appropriate size will be fine as well (though most consumer NiMH C-cells are just adapted up AAs - so might not be so great there).

6 NiMH AA batteries would still be fine (way better than the typical alkaline alternatives I would think). I will test this out as soon as I fix my soldering iron (or get a new one). I actually have "real" NiMH C batteries which are probably way overkill for anything I could do with them.

I'm unclear how much current is needed for reliable ignition of a cluster 3 Estes igniters. My 6 Cs can drive about 5.5 A total into 0.25 ohms, which is about 1.8 A per igniter which I would think is borderline. I want to see what 8 NiMH AAs can do (also awaiting a working soldering iron).

The only Estes controller that uses a 9V is the little orange Astron II. There, Duracell or Energizer again are the way to go. I don't know of a viable rechargeable for that application.

9V rechargeables (such as these) would probably work well for a modest number of single engine launches. I'd be mighty curious to test one and see how it performs but am too cheap to buy it just for that purpose. Also, although I have a charger for them, most people probably don't; given there limited performance I wouldn't recommend the investment.
 
Last edited:
Interesting....I hadn't seen rechargeable "9V" batteries in awhile. Those, of course, would be like the NiCd ones at 7.2V. I wouldn't even try one that wasn't "low self-discharge" or it'd be dead every time I wanted to go fly. For 9V applications good ol' alkaline would still be my preference. Small NiMH cells and I have never gotten along well.

Yeah, 1.8A per igniter into Estes igniters/starters would be iffy for a cluster. If one really wants to fly a cluster off of a handheld controller Quest Q2G2s are probably the real answer.
 
Energizer Lithium Advanced batteries have a PTC which limits the output to 5A. Thats why I use them with my RRC3.
 
I have a Duracell in my newer Estes controller and have around 40 launches on one battery so far. Tried a cheaper brand and it wouldn't light the starter.
 
The construction worker orange one that Estes sells. Astron II I think? They fire pretty quick. Having the right 9V in that controller is the difference between it being a pile of crap and a pretty reasonable launcher. I'm planning on running the battery until it doesn't ignite motors anymore - so far it just keeps on going.
 
Agree with Ryan about the little Astron II controller. I did some quick current tests some time ago with a Quest 9V and the Electron Beam (4AAs) and found that for the amount of time it takes to fire an igniter (and given good quality batteries in both) the current delivery was pretty similar. The 9V sags faster and further under load, but if the rocket isn't gone in a second or so something else is wrong anyway. And sometimes the bridgewire doesn't burn through - I've gotten three flights off of one igniter a couple of times. :)
 
Those are lithium ion, not lithium polymer. They are probably not a high-current chemistry. Here are some comparable ones from Tenergy: https://www.all-battery.com/Li-ionRechargeableBattery-30593.aspx, you can see they're rated for 350 mA max continuous current.

It is certainly possible they'll work fine in this application, but they're not really designed for it. I would bet the NiMH 9V batteries would perform better. I would love to do a big comparison test of all these, but I'd rather spend the time building. :)

In the meantime, I might pick up some of those Li ionfor my smoke detectors, I hate tossing half-used disposables on every change....

I *really* want to design a controller around one of these guys: https://www.all-battery.com/72v10000mahnicdbattery-21047.aspx. :)
 
I've been using the same Duracell 9v basic copper top in my Estes launcher since May. It has well over 50 launches on it.
 
Hijack on: Which of the above 9v rechargeable would be recommended for my Alts, an Olsen & a PML Co-Pilot ver.1 with built battery holders? Hijack Off.
 
Those are lithium ion, not lithium polymer. They are probably not a high-current chemistry. Here are some comparable ones from Tenergy: https://www.all-battery.com/Li-ionRechargeableBattery-30593.aspx, you can see they're rated for 350 mA max continuous current.

It is certainly possible they'll work fine in this application, but they're not really designed for it. I would bet the NiMH 9V batteries would perform better. I would love to do a big comparison test of all these, but I'd rather spend the time building. :)

In the meantime, I might pick up some of those Li ion for my smoke detectors, I hate tossing half-used disposables on every change....

I *really* want to design a controller around one of these guys: https://www.all-battery.com/72v10000mahnicdbattery-21047.aspx. :)
It's a case of semantics. LiPo batteries are Li-ion batteries. The electrolyte in a polymer battery still has some liquid......... Check out https://en.wikipedia.org/wiki/Nine-volt_battery for info on definitions, the chemistry and internal construction of 9 volt transistor batteries. I also suggest you read the reviews and comments at the bottom of the Amazon page.

How much current you can pull from a battery is determined by it's chemistry and construction. Electrode area of the individual cells within the battery determines the current flow, as does the separations of the electrodes and the resistance of the electrolyte. Chemical diffusion determines the peak current capability versus the continuous current capability.

I wouldn't put to much stock in any of the specs listed for the battery sold on Amazon unless a manufacturer's data sheet is included. I will assume the individual cells are either pouch cells or cylindrical cells either of which will source a lot more than 350 ma. The impedance of any Li-ion/polymer battery is going to be lower than an alkaline battery, and should be lower than a NiMH. The old Sanyo NiCad was very low and could source 20 amps, but that battery has been oop for nearly 10 year as NiCads have a multitude of environmental and lifetime issues and have been virtually replaced by NiMH chemistry.

My guess is that you should get 5+ amps for the 1 second power burst required to fire an Estes igniter.

Bob
 
I have a homemade controller that I whipped up in a hurry last spring, with two 9v generic batteries in series. Probably 30 launches and charge tests on it so far.
Hasn't shown any signs of slowing down yet.

-Hans
 
I received my pack of four "9V" lithium batteries and the little charger (see the link in post 17 above) from Amazon today. I'm getting ready to run my club's launch tomorrow at the moment, so I can't do any measurements on them this evening. Hopefully I'll get around to it Sunday and post some results comparing delivered current with fresh Duracell 9Vs in either the Astron-II controller or a Quest controller (I have both handy). I will say that the batteries are noticeably lighter than a Duracell. The two I charged have resting open-circuit voltage of 8.38 and 8.44V (consistent with them being two-cell LiPolys inside) vs. 9.38V for a Duracell I have in stock. But if the lithiums can deliver current like any recent-generation LiPoly can, the lower voltage will not be an issue. I hope to find out Sunday.
 
I received my pack of four "9V" lithium batteries and the little charger (see the link in post 17 above) from Amazon today. I'm getting ready to run my club's launch tomorrow at the moment, so I can't do any measurements on them this evening. Hopefully I'll get around to it Sunday and post some results comparing delivered current with fresh Duracell 9Vs in either the Astron-II controller or a Quest controller (I have both handy). I will say that the batteries are noticeably lighter than a Duracell. The two I charged have resting open-circuit voltage of 8.38 and 8.44V (consistent with them being two-cell LiPolys inside) vs. 9.38V for a Duracell I have in stock. But if the lithiums can deliver current like any recent-generation LiPoly can, the lower voltage will not be an issue. I hope to find out Sunday.
Can you do ground tests in your backyard with just the igniters?

Please keap us posted!
 
I'll be measuring delivered current directly rather than just firing igniters, though I might do that as well.

I did learn today - on a very slightly related topic - that four Duracell Ds in a 1966-vintage Estes Electro-Launch pretty much instantly melts Estes Solar igniters. You push the button, it GOES NOW! But that's really a different discussion....
 
OK - here are some results. There is good news and there is bad news.

The good news is that these little EBL 600 mAh "9V" batteries can deliver plenty of current - in my quick test which basically involved putting a multimeter in the 10A measuring range in the place of the igniter and pushing the fire button for short periods I saw over 4.5A delivered for an approximately half-second period, compared to less than half of that from the Duracell 9V that was in the Astron II controller before I put the rechargeable in. I also fired a Solar igniter and it went up pretty much instantly, as you'd expect.

The bad news is, after doing a series of four short button presses to get a sense of how fast the current fell, the first battery I tested went open-circuit. So, I opened it up to see if there was a protection circuit or something that might have shut it down. There is, in fact, along with two 600 mAh LiPoly cells, some circuitry at the top inside the case. I didn't see any burnt components, but I did find a failed connection between the positive tab of one of the cells and the board. It looks as if the weld wasn't too good at that particular connection and it failed at that current level after I did the four quick tests in succession.

Since I have four of these batteries (and no other immediate applications, though I could put one in a smoke detector I suppose) I decided to try the second one, and it survived five quick short bursts at 4.5A+ and then happily fired an igniter. So I left that one in the launch controller and will use it next time I go out to fly by myself and we'll see how it does. I have a spare Duracell in the bag with it - just in case.

So - bottom line - there is certainly sufficient power delivery to launch a low-power rocket but the quality of the internal construction might not be what we'd want. I certainly would not - based on what I've just seen - put one of these EBL rechargeables into a rocket for use with deployment electronics. If it fails and an LPR rocket doesn't fly, that's one thing. If an MPR or HPR model comes in ballistic because one of these things fails, that's another story altogether.
 
Those are lithium ion, not lithium polymer.

As Bob noted, "lithium polymer" cells ARE lithium ion.

And I can confirm, via dissection, that what is inside the case of the batteries in Bob's link is two lithium polymer cells marked 600 mAh capacity.

My guess is that you should get 5+ amps for the 1 second power burst required to fire an Estes igniter.

Bob

Great guess.... I saw 4.6A measured as described just above.
 
Last edited:
I guess you put some sort of resistance in your battery and multimeter circuit to model the resistance of the igniter?
 
No - just straight through the multimeter on 10A setting. So yes, the currents are probably overstated.

Now that you bring it up, I'll need to measure a few random age Solar ignitors/starters to get a sense of what a good resistance value should be then try to figure out how to put something of that resistance in series with the multimeter measurement.

That said, it is clear that the internal resistance of the li-poly-based rechargeable is lower since it can deliver double the current under the same conditions (and that with an open-circuit voltage that is about 0.6V lower to begin with). So for launcher use - as long as the thing doesn't fail internally at those currents - it should be fine.

But to circle back to your original question: The Estes #2230 E launch controller uses AA cells, not 9V batteries. So all of this is interesting but not applicable to use in the controller you inquired about in the first post.
 
Last edited:
Back
Top