RRC3 Altimeter Using Battery Life Very Fast

[Sailfish1957]

Has anyone encountered an RRC3 using up battery life quickly? I have mine connected to the BTMM (blue tooth module) which is on-board the sled, so I can change settings and monitor the RRC3 by blue tooth. I have a screw switch connected to the "switch" block on the RRC3; the battery is hooked up to the battery connection block on the RRC3. Can that be draining the battery? The setup seems to draw the battery down fast. Should I connect the screw switch between the battery and the RRC3, and jumper the "switch" connection on the RRC3. That would completely isolate the battery - should solve the problem. Thoughts???

 

[crossfire]

Contact RRC3 manufacturer and ask them

 

[Handeman]

I've aways jumpered the switch connection and put my pull pin microswitch and screw switch in series with the battery. I'm using Stratologger CF altimeters, but baring a hard landing or other anomaly, the 9V battery is usually good for 30 flights and 3 years before it's voltage drops below 9.0V.

Just like your phone, when you start turning on transmitters like bluetooth, the battery life will drop. There should be something in your owners manual, or on the website under specifications that tells you what the power draw is with various options. It should also tell you if the switch contacts are in series with the incoming power or if there is some vampire power draw when the switch contacts are open.

As @crossfire said, the manufacturer is going to be your best source of accurate information.

 

[mikec]

You don't say what kind of battery you're using or how long it lasts. It's not clear to me from the Missileworks docs how much power the BT will use or if this is a supported mode, so you should definitely ask them. I'm not sure how you connected the BT module but if you bypassed the RRC3 switch then it may be on all the time, even when the RRC3 is off?

 

[Titan II]

Should I connect the screw switch between the battery and the RRC3, and jumper the "switch" connection on the RRC3. That would completely isolate the battery - should solve the problem.

Yes.

 

[Banzai88]

MW has long maintained that the switch terminals on the board are already in series with the power and that jumpering them and putting the switch elsewhere won't make any difference electrically.

As to the OP's concerns, what type and size battery? The RRC3 uses almost nothing (as in with the lipo that I use, an hour of pad time and a flight recharges less than 20 miliamps).....but the BT module is crazy power hungry.

 

[mikec]

MW has long maintained that the switch terminals on the board are already in series with the power and that jumpering them and putting the switch elsewhere won't make any difference electrically.

Sure, but if the OP is connecting the BT to the battery inputs, those are in front of the switch.

 

[user 30299]

Sure, but if the OP is connecting the BT to the battery inputs, those are in front of the switch.

The Missile Works BT module hooks into the Comm Port on the RRC3. It can only be powered when the RRC3 is turned on.

 

[mikec]

The Missile Works BT module hooks into the Comm Port on the RRC3. It can only be powered when the RRC3 is turned on.

Ah, thanks. https://www.missileworks.com/app/download/965482686/mDACS+USB-IO+User+Manual+v160.pdf isn't super-clear and I've never seen one in person. The manual's "note an external battery/power‐source and power switch are required to make this operate" was also a bit confusing.

So the OP's problem is simply that the BT module uses a lot of power, and that can't be solved with different switching? The RRC3 manual says the comm port has battery voltage on it (pins 1 and 5) and I'm not sure if they're switched or not, the manual doesn't say.

 

[user 30299]

Ah, thanks. https://www.missileworks.com/app/download/965482686/mDACS+USB-IO+User+Manual+v160.pdf isn't super-clear and I've never seen one in person. The manual's "note an external battery/power‐source and power switch are required to make this operate" was also a bit confusing.

So the OP's problem is simply that the BT module uses a lot of power, and that can't be solved with different switching? The RRC3 manual says the comm port has battery voltage on it (pins 1 and 5) and I'm not sure if they're switched or not, the manual doesn't say.

The OP's problem may not be the BT module.

We don't know what they are using for a battery.

The BT module is a standard, off-the-shelf, HC-06 board.

This is right from the spec sheets on the HC-06:
"This device has a maximum range of 10 meters and works only as a slave in the Bluetooth protocol.
It operates at 3.3 V and has a current consumption of 30-40 mA during the pairing procedure and
of 8 mA during communication.

Missile Works will be able to properly answer the OP's question as long as they tell Missile Works what
they are using for a battery, and define what they mean by "using the battery life up quickly"; 30 min.,
an hour, two hours, ?

 

[Sailfish1957]

I've aways jumpered the switch connection and put my pull pin microswitch and screw switch in series with the battery. I'm using Stratologger CF altimeters, but baring a hard landing or other anomaly, the 9V battery is usually good for 30 flights and 3 years before it's voltage drops below 9.0V.

Just like your phone, when you start turning on transmitters like bluetooth, the battery life will drop. There should be something in your owners manual, or on the website under specifications that tells you what the power draw is with various options. It should also tell you if the switch contacts are in series with the incoming power or if there is some vampire power draw when the switch contacts are open.

As @crossfire said, the manufacturer is going to be your best source of accurate information.

To all, thanks for the advice. I have changed the wiring and now jumper the switch; isolating the battery.

 

[Dan Griffing]

The Missile Works BT module hooks into the Comm Port on the RRC3. It can only be powered when the RRC3 is turned on.

View attachment 578194

I have a BT module but my iPhone doesn't recognize it, and the Missile Works site only says its under development.

Does anyone have any documentation for this, and how to get it working?

I'm looking for a way to ground test my deployment charges with my RRC3 and was hoping that the BT interface would be a wireless way to do it.

 

[user 30299]

I have a BT module but my iPhone doesn't recognize it, and the Missile Works site only says its under development.

Does anyone have any documentation for this, and how to get it working?

I'm looking for a way to ground test my deployment charges with my RRC3 and was hoping that the BT interface would be a wireless way to do it.

The Missile Works BT module (HC-06 board)) does not work with Apple products.

The HC-06 uses a "Bluetooth Classic" protocol/design. Apple uses Bluetooth Low Energy (BLE).

You can use the mDACS program to ground test your RRC3 setup through the BT module.
The program can be download from the Missile Works website.

 

[Dan Griffing]

The Missile Works BT module (HC-06 board)) does not work with Apple products.

The HC-06 uses a "Bluetooth Classic" protocol/design. Apple uses Bluetooth Low Energy (BLE).

You can use the mDACS program to ground test your RRC3 setup through the BT module.
The program can be download from the Missile Works website.

But is there a wireless option for testing ejection charges with the RRC3?

Until now I’ve used the Eggtimer Proton, but have had problems at the range when I couldn’t get WiFi to work to arm the ejection charges.

 

[user 30299]

But is there a wireless option for testing ejection charges with the RRC3?

Until now I’ve used the Eggtimer Proton, but have had problems at the range when I couldn’t get WiFi to work to arm the ejection charges.

What you're asking is if the RRC3's ejection charges can be tested through a smart phone. No, they cannot.

You can test them wirelessly through the mDACS program on a Windows computer via the Bluetooth module.

The module probably has a 25 ft. to 30 ft. working distance.


I should mention that the charges are fired through mDACS's Simulation function. If you have both Drogue
and Main charges hooked up - it will fire them in the altitude sequence you have programmed in the RRC3.
You can watch the simulation on your computer as the rocket approaches apogee (Drogue) event, and when
it falls to the Main event.

Most people will use LEDs or Christmas tree lights in place of the charges when they run the simulation.
This way you can have the RRC3, or av-bay, sitting on the bench and watch the lights come on.

 

[wonderboy]

With regard to the wiring options for the screw terminals on the RRC3, just know that there really isn't a difference in how the battery is isolated depending on how you wire it up (nothing that would cause more or less battery drain while off).

The 4 position screw terminal provides two terminals for the battery, and two terminals for a switch. The battery negative terminal connects to the PCB ground and is not in the loop for the other terminals. The battery positive terminal actually is just connected via the circuit board to the first switch terminal. The second switch terminal is the one that feeds the battery voltage to the altimeter circuits.

This gives you 3 options to wire up your battery and switch. All three provide the same level of battery drain isolation, one isn't better than the others from that aspect. I choose to connect mine via what I've labeled as the "Minimal" option, to eliminate screw terminal connections.


I hope this info helps clear up how the battery and switch connections work on the RRC3.

 

[wonderboy]

For reference, I measured the current draw of my RRC3 using a 2cell Lipo battery (7.4V nominal) both with and without the bluetooth module connected.

My numbers were (edited the formatting below to match 1cell results posted later in the thread):

w/o Bluetooth:
Beeping: 125mA
Quiet: 6.5mA

w/ Bluetooth:
Beeping: 165mA
Quiet: 45mA

The "Beeping" and "Quiet" just means that the value jumps up as the beeper is beeping out continuity checks. The beeper definitely is the largest sink of current on the system. Also note that this was the long "no charges connected" beep, which is much longer in duration than the short duration chirps you normally get when deployment charges are connected.

I didn't have a 1cell Lipo charged to see if the numbers change, but I expect they should be very similar. If anyone really needs to know, I can charge up a battery and test it.

EDIT: My battery is a tiny 120mAh battery. With the numbers above (ignoring the extra current drawn when the beeper beeps) my battery would be depleted (assuming 100% of rated capacity is available) in:

• ~2.7 hours with bluetooth running
• ~18 hours without bluetooth

This is not to say that the charges would even be able to be fired after sitting there for so long, but just simply how long the thing should stay alive if left on.

 

[Handeman]

For reference, I measured the current draw of my RRC3 using a 2cell Lipo battery (7.4V nominal) both with and without the bluetooth module connected.

My numbers were:
Without Bluetooth: 6.5mA (no beeping) 125mA (with beeping)
With Bluetooth: 45mA (no beeping) 165mA (with beeping)

The "no beeping" and "with beeping" just means that the value jumps up as the beeper is beeping out continuity checks. The beeper definitely is the largest sink of current on the system. Also note that this was the long "no charges connected" beep, which is much longer in duration than the short duration chirps you normally get when deployment charges are connected.

I didn't have a 1cell Lipo charged to see if the numbers change, but I expect they should be very similar. If anyone really needs to know, I can charge up a battery and test it.

EDIT: My battery is a tiny 120mAh battery. With the numbers above (ignoring the extra current drawn when the beeper beeps) my battery would be depleted (assuming 100% of rated capacity is available) in:

• ~2.7 hours with bluetooth running
• ~18 hours without bluetooth

This is not to say that the charges would even be able to be fired after sitting there for so long, but just simply how long the thing should stay alive if left on.

Great numbers. If you are using a 1S battery with half the voltage (3.7V), I would expect the current to double.

It would be interesting to find out for sure, if you don't mind running it again with the 1S battery.

 

[wonderboy]

1 Cell Lipo results (450mAh 1cell Lipo fresh off the charger at 4.2V)

w/ Bluetooth:
Beeping: 150mA
Quiet: 45mA

w/o Bluetooth:
Beeping: 110mA
Quiet: 6.4mA

 

[Sailfish1957]

With regard to the wiring options for the screw terminals on the RRC3, just know that there really isn't a difference in how the battery is isolated depending on how you wire it up (nothing that would cause more or less battery drain while off).

The 4 position screw terminal provides two terminals for the battery, and two terminals for a switch. The battery negative terminal connects to the PCB ground and is not in the loop for the other terminals. The battery positive terminal actually is just connected via the circuit board to the first switch terminal. The second switch terminal is the one that feeds the battery voltage to the altimeter circuits.
View attachment 579084
This gives you 3 options to wire up your battery and switch. All three provide the same level of battery drain isolation, one isn't better than the others from that aspect. I choose to connect mine via what I've labeled as the "Minimal" option, to eliminate screw terminal connections.
View attachment 579086

I hope this info helps clear up how the battery and switch connections work on the RRC3.

Thanks for all the info.

 

[Handeman]

1 Cell Lipo results (450mAh 1cell Lipo fresh off the charger at 4.2V)

w/ Bluetooth:
Beeping: 150mA
Quiet: 45mA

w/o Bluetooth:
Beeping: 110mA
Quiet: 6.4mA

Interesting. It's actually a little less than the 2S 7.4V battery. Obviously there is a voltage regulator on the board that feeds the same voltage to everything, no matter what the battery voltage is. I wonder if the regulator using less current because the input is closer to the output is the reason for the slightly low current draw with the 1S?

 

[Sailfish1957]

Interesting. It's actually a little less than the 2S 7.4V battery. Obviously there is a voltage regulator on the board that feeds the same voltage to everything, no matter what the battery voltage is. I wonder if the regulator using less current because the input is closer to the output is the reason for the slightly low current draw with the 1S?

Interesting. Thank you for the info.

 

[wonderboy]

I wonder if the regulator using less current because the input is closer to the output is the reason for the slightly low current draw with the 1S?

I think this is exactly it. The regs arent dumping as much power since the voltage is closer to the final value.

 

[Voyager1]

I think this is exactly it. The regs arent dumping as much power since the voltage is closer to the final value.

For this reason, you need to be careful about using a 1S LiPo with the RRC3, particularly when its voltage drops much below 3.6-3.7V.

The other issue with using a 1S LiPo is that when using the external LCD module, you might not have sufficient voltage to use it reliably. That has been my experience, however YMMV.

 

[Dan Griffing]

I think this is exactly it. The regs arent dumping as much power since the voltage is closer to the final value.

Great explanation!

 

[Sailfish1957]

What you're asking is if the RRC3's ejection charges can be tested through a smart phone. No, they cannot.

You can test them wirelessly through the mDACS program on a Windows computer via the Bluetooth module.

The module probably has a 25 ft. to 30 ft. working distance.


I should mention that the charges are fired through mDACS's Simulation function. If you have both Drogue
and Main charges hooked up - it will fire them in the altitude sequence you have programmed in the RRC3.
You can watch the simulation on your computer as the rocket approaches apogee (Drogue) event, and when
it falls to the Main event.

Most people will use LEDs or Christmas tree lights in place of the charges when they run the simulation.
This way you can have the RRC3, or av-bay, sitting on the bench and watch the lights come on.

I have used both the mDAC's Simulation and an actual vacuum chamber with great results on each. The vac chamber sim file can be saved and then loaded into mDACs post-test, then displays when (altitude) the ejection charges were fired, along with other cool info (voltage drop etc). I use tree lights and they are excellent for this.

IMHO, the vacuum chamber is very sound, as it should give a very accurate chunk of data.

 

[Sailfish1957]

To all, thanks for the advice. I have changed the wiring and now jumper the switch; isolating the battery.

I no longer have battery drop issues. Maybe it was a bad batt. Thanks to all!!