Eggtimer/Altimeter sled battery placement

Discussion in 'Rocketry Electronics and Software' started by Mr G, Mar 12, 2018.

Help Support The Rocketry Forum by donating:

  1. Mar 12, 2018 #1

    Mr G

    Mr G

    Mr G

    Well-Known Member

    Joined:
    Feb 10, 2013
    Messages:
    416
    Likes Received:
    25
    It appears that the Eggtimer needs at least two batteries function.

    Both Eggtimers I have are set up for a 9v battery for deployment leaving a 3.7v battery (Lipo, I presume) for everything else. If so, where do people put the second battery on an Adaptive Aerospace 54mm altimeter sled?

    There is dedicated space for a 9v but it is not clear where another battery would fit? Any photos of how you did this would be very helpful.
     
  2. Mar 12, 2018 #2

    Keisling

    Keisling

    Keisling

    Licensed Practical Rocket Surgeon

    Joined:
    Jan 22, 2017
    Messages:
    173
    Likes Received:
    52
    Location:
    Florida
    I don't think the Eggtimer "needs" two batteries. You can use two but most people wire it with only one.
     
  3. Mar 12, 2018 #3

    timbucktoo

    timbucktoo

    timbucktoo

    Well-Known Member Staff Member Global Mod

    Joined:
    Jun 13, 2014
    Messages:
    5,975
    Likes Received:
    527
    Gender:
    Male
    Location:
    Cocoa Beach
    Are you referring to the Eggtimer TRS or the Eggtimer?
    I use 2 batteries with the TRS, one for pyro charges and one for GPS. I believe that Cris recommends that set-up and there are 2 connections for such.
    But like Keisling says, the Eggtimer itself only requires 1 battery.
     
  4. Mar 12, 2018 #4

    ksaves2

    ksaves2

    ksaves2

    Lifetime Supporter TRF Lifetime Supporter

    Joined:
    Nov 25, 2009
    Messages:
    5,619
    Likes Received:
    104
    The early version egg-timer deployment altimeters needed a 3.7 volt lipo to power the electronics and a separate pyro battery. I think a later version there was an option to have it operate off of One battery. Kurt
     
  5. Mar 12, 2018 #5

    cerving

    cerving

    cerving

    Owner, Eggtimer Rocketry TRF Sponsor TRF Supporter

    Joined:
    Feb 3, 2012
    Messages:
    3,177
    Likes Received:
    350
    You can use the same power for deployment power as the altimeter power, the second battery option prevents high-current igniters from causing a brownout that resets the altimeter. Typical ematches don't draw enough current to cause this to happen, so going with one battery is fine. Note that we generally do not recommend using 9V batteries... a 2S LiPo (or a 1S if you wire the Eggtimer Classic for it) puts out a lot more current, and they're very reliable. Whatever battery you end up using, ground test it thoroughly before you fly it.
     
  6. Mar 14, 2018 #6

    Mr G

    Mr G

    Mr G

    Well-Known Member

    Joined:
    Feb 10, 2013
    Messages:
    416
    Likes Received:
    25
    The two Eggtimers I have are both version D's and set up for 9v. What I can't find are good photos showing how to use only one 9v battery for everything. For those of us that are total neophytes in electronics and only wanting to start out with basic dual deployment, descriptions of so many options is very confusing.

    Can anyone provide up-close photos of and instructions on how to use just one 9v battery given that there are 4-pin locking headers? And how do you hook up one battery between the two deployment channels plus one for the processer?

    "If you are using both Channel A (Main) and Channel B, and they are OK on the same battery (i.e. they’re both either servos or both igniters), then you can jumper the BATA and BATB terminals together: + to +, and – to - ."

    What does a jumper look like? Where and how does it attach to a locking header? It would be really helpful to have some simple instructions, diagrams and photos to show how this all goes together.
     
  7. Mar 14, 2018 #7

    rharshberger

    rharshberger

    rharshberger

    Well-Known Member

    Joined:
    Oct 13, 2014
    Messages:
    8,362
    Likes Received:
    792
    Gender:
    Male
    Location:
    Pasco, WA
    Pictured just above the red wire and below the screw on the altimeter is a jumper, it is simply a U-shaped wire inserted into the two holes and soldered in place.

    MiniFrenzyXLdd19.jpg
     
  8. Sep 6, 2019 #8

    SierraDrinker

    SierraDrinker

    SierraDrinker

    Member

    Joined:
    Jun 17, 2017
    Messages:
    18
    Likes Received:
    3
    Gender:
    Male
    Location:
    Okotoks, Alberta
    Hi Cris,

    Do you have a recommendation for the number of mah I need for a 1S to run an eggtimer classic off one battery? I was using a 9v, but want to go with a smaller, lighter option.

    Thanks,

    Jason
     
  9. Sep 6, 2019 #9

    cerving

    cerving

    cerving

    Owner, Eggtimer Rocketry TRF Sponsor TRF Supporter

    Joined:
    Feb 3, 2012
    Messages:
    3,177
    Likes Received:
    350
    A 300 mAH 1S should be fine. You can probably go down to 120 mAH, maybe smaller... it depends on your ematches. The Classic itself only uses about 8 mA.
     

Share This Page