# 9 volt battery review

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#### mpitfield

##### Moderator
Staff member
TRF Lifetime Supporter
Global Mod
For you diehard 9v battery fans, here is what I thought was a decent review of the top two 9v batteries.

#### neil_w

##### Hunkered down
TRF Supporter
Wow, no wonder they suck as launch controllers. 2.5 ohm internal resistance, and these are the *good* brands. Yikes. So they're maxing out at less than 4A current delivery when *new*.

#### mbeels

##### Putting the tree in rocketry
TRF Supporter
They're great for smoke detectors, but not much else.

#### Handeman

##### Well-Known Member
TRF Supporter
For you diehard 9v battery fans, here is what I thought was a decent review of the top two 9v batteries.

This really doesn't apply to rocketry applications.

I've found that using a 9V for a DD altimeter for 3 years, with 6-8 flights a year, will only drop it to about 8.9 VDC because the discharge per flight is so low. The discharge capacity of the battery is more than enough to run altimeters and fire ematches for years. Probably for the life of the rocket.

I did have a rocket that hung in a tree 5 full days and both altimeters were still beeping altitude. One was down to 4.6 VDC and the other to 6.8 VDC. I didn't test them, but I suspect that they might have both been able to fire ematches yet.

The critical thing about these batteries that the video didn't address was internal construction. It's the dependable operation in extreme conditions that are really the consideration here. I only use the copper top Duracell because they are tack welded internal connections and have proven durable under the harsh flying conditions. Even then, I replace the batteries if they have a hard landing, like coming in on a drogue only.

I am a diehard 9V battery fan. I fly 9VDC batteries because they are dependable, more than capable, and don't require all the maintenance of the LiPos I've been using for my GPS electronics. Since I seldom download flight data, I don't open my av-bays for years at a time. I couldn't do that running anything but 9V batteries.

+1

#### Rocketjunkie

##### Addicted to APCP
I use Duracells. They have the internal cells with welded connections. Energizer relies on the case to hold the cells in contact. I've always used 9V batteries and replace when open circuit reaches 9.2V.

#### BEC

##### Well-Known Member
Wow, no wonder they suck as launch controllers. 2.5 ohm internal resistance, and these are the *good* brands. Yikes. So they're maxing out at less than 4A current delivery when *new*.
Yeah, that was one of the things that came to my mind. RIP Astron II launch controller. Long live Electron Beam... .

#### jbr

##### Well-Known Member
commercial duracell is the best, normally has 9.8 to 10v new

#### Bat-mite

##### Rocketeer in MD
I use Duracells. They have the internal cells with welded connections. Energizer relies on the case to hold the cells in contact. I've always used 9V batteries and replace when open circuit reaches 9.2V.
I've done DD flights reliably with voltage down to 8.8V.
I use Duracells. They have the internal cells with welded connections.
Yes, that is a plus. However, I also use Energizers, or even off-brands, always attached to the sled with the leads pointing down. That way, the acceleration force pushes the connections together at the bottom.

#### neil_w

##### Hunkered down
TRF Supporter
Zoinks, even the Duracell Procells list >3 ohms internal resistance. Just say no to 9V launch controllers, at least if you're using Estes solar starters. Note that this is a totally separate issue than batteries for DD.

#### jrap330

##### Retired Engineer, NAR # 76940
Please explain why you state they suck for launch controllers. I have an Quest Launch controller (2002) and the few times I used it, maybe 10 tomes, my Estes engines with the older igniters fired. did you mean to say they will not ignite AP motors. OR are difficult with dual deployment (altimeter) ejection charges.

#### neil_w

##### Hunkered down
TRF Supporter
Simply put, 9V batteries can only barely supply enough current to light a motor with the new Estes starters, and that's good brand batteries when fresh and new. And even then you often need to hold the button down for a long time. In other words, conditions have to be just right for them to work.

There are many, many accounts out there of folks who have been unable to get their 9V controllers to launch because the battery wasn't perfect (I'll include myself in that group). Sure they work sometimes, but it's not worth the trouble when there are better alternatives.

Rechargeable 9V batteries will do a much better job in the same controllers, but few people have (or want to invest in) a charger just for that purpose.

#### Stephen R

##### New Member
We did some research for a 9V battery format to power a home made flight computer with BMP280 altimeter, MPU-6050, ESP32 Microcontroller and more importantly ignite e-match for recovery and the only one we found that could provide continuous 1000mA in the 9v format was the Energizer Ultimate Lithium.

nice work

#### mpitfield

##### Moderator
Staff member
TRF Lifetime Supporter
Global Mod
We did some research for a 9V battery format to power a home made flight computer with BMP280 altimeter, MPU-6050, ESP32 Microcontroller and more importantly ignite e-match for recovery and the only one we found that could provide continuous 1000mA in the 9v format was the Energizer Ultimate Lithium.

It is a bit pricey at about 15\$ Canadian but for our need, the ratio power/weight (34 grams) was good at the time.
Welcome to the forum, what project was this for? It looks similar to some of the projects JBP has worked on.

#### Stephen R

##### New Member
Welcome to the forum, what project was this for? It looks similar to some of the projects JBP has worked on.
Thank you Michael,

I have been silently following this community for the pas few months. I especially like (the now 24 pages) post "I could use just a little guidance" from Jim Jarvis

Regarding this project, we call it MORGAN (for MOdel Rocket Guidance And Navigation).

It is a hobby project started with a friend at the end of last year, which also serves as a cool way to spend time while confined at home. It is our first experience in the model rocketry world. We were strongly influenced by Joe Barnard (BPS.space) and the rocketryforum.com board.

The flight computer is our own design. It was built with the following requirements in mind:
• Fast MCU, plenty of GPIO, Wifi & BLE, relatively low power (we chose the ESP-32 Microcontroller)
• Attitude stabilisation (Pitch/Yaw) using either canards fins and/or Thrust Vectoring Control (TVC) and soon, Reaction Wheel (for roll control).
• Up to 4 servos connections independently controlled using PID loops.
• Altitude / Apogee detection using BMP-280 and MPU-6050 for Gyro/Axcel.
• 4 pyros channels (using mosfets) for deployment of recovery systems and stage separation.
• Must be able to log as much information from the flight passible.
• On board 64Mb Flash memory + optional SD Card for data logging.
• Battery voltage monitoring (regulated from 7~12v down to 5v and 3.3v).
• GPS capability (not used yet)
• Bluetooth bi-directional communication for parameters configuration and pre-flight systems tests.
• And the all important flashing RGB Led and Piezzo Buzzer
The firmware is currently being fine tuned and we are finishing work on the front-end configuration/tuning Web-APP that can be used in the field on a cell phone or a laptop.

We hope to be able to fly it by the end of this month after extensive ground tests. If we achieve a few successful low altitude flights, we would like to get certified by a local club to do more serious stuff.

Last edited:

#### mpitfield

##### Moderator
Staff member
TRF Lifetime Supporter
Global Mod
Thank you Michael,

I have been silently following this community for the pas few months. I especially like (the now 24 pages) post "I could use just a little guidance" from Jim Jarvis

Regarding this project, we call it MORGAN (for MOdel Rocket Guidance And Navigation).

It is a hobby project started with a friend at the end of last year, which also serves as a cool way to spend time while confined at home. It is our first experience in the model rocketry world. We were strongly influenced by Joe Barnard (BPS.space) and the rocketryforum.com board.

The flight computer is our own design. It was built with the following requirements in mind:
• Fast MCU, plenty of GPIO, Wifi & BLE, relatively low power (we chose the ESP-32 Microcontroller)
• Attitude stabilisation (Pitch/Yaw) using either canards fins and/or Thrust Vectoring Control (TVC) and soon, Reaction Wheel (for roll control).
• Up to 4 servos connections independently controlled using PID loops.
• Altitude / Apogee detection using BMP-280 and MPU-6050 for Gyro/Axcel.
• 4 pyros channels (using mosfets) for deployment of recovery systems and stage separation.
• Must be able to log as much information from the flight passible.
• On board 64Mb Flash memory + optional SD Card for data logging.
• Battery voltage monitoring (regulated from 7~12v down to 5v and 3.3v).
• GPS capability (not used yet)
• Bluetooth bi-directional communication for parameters configuration and pre-flight systems tests.
• And the all important flashing RGB Led and Piezzo Buzzer
The firmware is currently being fine tuned and we are finishing work on the front-end configuration/tuning Web-APP that can be used in the field on a cell phone or a laptop.

We hope to be able to fly it by the end of this month after extensive ground tests. If we achieve a few successful low altitude flights, we would like to get certified by a local club to do more serious stuff.
Hi Stephen,

Jim and Joe are two great choices for inspiration. I seem to recall a thread a while back announcing this project or something similar. I am thrilled to see it come to fruition! I read the price in Canadian comment, so I am assuming you are in Canada, which province, which clubs?

#### Stephen R

##### New Member
Hi Stephen,

Jim and Joe are two great choices for inspiration. I seem to recall a thread a while back announcing this project or something similar. I am thrilled to see it come to fruition! I read the price in Canadian comment, so I am assuming you are in Canada, which province, which clubs?
We are in suburbs of Montreal, Quebec.

The only club that I am aware of in the province is : http://www.clubqf.ca/index.html which seems to be a division of the Canadian Association of Rocketry http://www.canadianrocketry.org/index.php

Unfortunately they do not have many events. The good thing is that we will have more time to be ready to launch at their next event (if we are allowed).

#### mpitfield

##### Moderator
Staff member
TRF Lifetime Supporter
Global Mod
We are in suburbs of Montreal, Quebec.

The only club that I am aware of in the province is : http://www.clubqf.ca/index.html which seems to be a division of the Canadian Association of Rocketry http://www.canadianrocketry.org/index.php

Unfortunately they do not have many events. The good thing is that we will have more time to be ready to launch at their next event (if we are allowed).
Hi Stephen,

Have you considered launching in the US? I am a member of URRG, which is about five hours from Montreal, four from my location, and they are a Tripoli Prefecture. They have a large event yearly, URRF (Upstate Research Rocketry Festival) and monthly club launches. The field is extensive, with an 18,000' waiver. I try to attend four URRG launches per year, and I have made some great friendships along the way. More importantly, from a development perspective, there are a lot of interesting people with a wide range of approaches to the same problems, it makes an inspirational environment for growth.