Battery life when running a transponder

For me (TERRA transponder with Nixie tubes display) - at most 4 hrs on
14Ah battery before radio (yes) becomes totally unuseable. This is for
flights in the middle of summer at 11-18000ft. Added load from sources
other than transponder is about 500mA.

This year I added a 7Ah emergency battery so I can land without having
to fumble for my handheld which most likely also has a dead battery
.

Cheers,
Henryk Birecki


On Jul 2, 9:21*am, Chris Nicholas wrote:
Can anybody tell me what battery life you get in practice, when
running a transponder from a dedicated lead-acid battery, and what
size battery that is? And what model of transponder is it?

Has anybody measured the actual current drawn during operation, if so
what is it?

I am particularly interested in flights which include some high
altitude, cold ambient operation such as in parts of North America.

I am only interested in modern, solid state transponder operation, not
the older Mode C with a heater for the height encoder.

I have been given figures which suggest that a 7-amp-hour battery
would run one for 12 hours at surface ambient conditions, and I wonder
if anything like that is achievable in practice.

Thansk - Chris N.

Chris N. (In UK, but collecting data from anywhere that has it!)

On Jul 2, 8:38*pm, Henryk Birecki wrote:
For me (TERRA transponder with Nixie tubes display) - at most 4 hrs on
14Ah battery before radio (yes) becomes totally unuseable. This is for
flights in the middle of summer at 11-18000ft. Added load from sources
other than transponder is about 500mA.

This year I added a 7Ah emergency battery so I can land without having
to fumble for my handheld which most likely also has a dead battery
.

Cheers,
Henryk Birecki



On Jul 2, 9:21*am, Chris Nicholas wrote:
Can anybody tell me what battery life you get in practice, when
running a transponder from a dedicated lead-acid battery, and what
size battery that is? And what model of transponder is it?

Has anybody measured the actual current drawn during operation, if so
what is it?

I am particularly interested in flights which include some high
altitude, cold ambient operation such as in parts of North America.

I am only interested in modern, solid state transponder operation, not
the older Mode C with a heater for the height encoder.

I have been given figures which suggest that a 7-amp-hour battery
would run one for 12 hours at surface ambient conditions, and I wonder
if anything like that is achievable in practice.

Thansk - Chris N.

Chris N. (In UK, but collecting data from anywhere that has it!)- Hide quoted text -

- Show quoted text -

With a becker transponder, 302,303, Dittle radio, and pda 4700 I get
about 3 hours on one 7amp/hour battery. Most of the flight at 14k and
above. When I fly in congested areas altitude is lower but 3 hours
seems to be about all I get there also. Older batteries get less. I
also have a hook-up for PCAS but I was not using it this week (in
shop). The solar option on the glider would be nice as that helps.

On Jul 2, 11:35*pm, Hal wrote:
On Jul 2, 8:38*pm, Henryk Birecki wrote:



For me (TERRA transponder with Nixie tubes display) - at most 4 hrs on
14Ah battery before radio (yes) becomes totally unuseable. This is for
flights in the middle of summer at 11-18000ft. Added load from sources
other than transponder is about 500mA.

This year I added a 7Ah emergency battery so I can land without having
to fumble for my handheld which most likely also has a dead battery
.

Cheers,
Henryk Birecki

On Jul 2, 9:21*am, Chris Nicholas wrote:
Can anybody tell me what battery life you get in practice, when
running a transponder from a dedicated lead-acid battery, and what
size battery that is? And what model of transponder is it?

Has anybody measured the actual current drawn during operation, if so
what is it?

I am particularly interested in flights which include some high
altitude, cold ambient operation such as in parts of North America.

I am only interested in modern, solid state transponder operation, not
the older Mode C with a heater for the height encoder.

I have been given figures which suggest that a 7-amp-hour battery
would run one for 12 hours at surface ambient conditions, and I wonder
if anything like that is achievable in practice.

Thansk - Chris N.

Chris N. (In UK, but collecting data from anywhere that has it!)- Hide quoted text -

- Show quoted text -

With a becker transponder, 302,303, Dittle radio, and pda 4700 I get
about 3 hours on one 7amp/hour battery. *Most of the flight at 14k and
above. *When I fly in congested areas altitude is lower but 3 hours
seems to be about all I get there also. Older batteries get less. *I
also have a hook-up for PCAS but I was not using it this week (in
shop). *The solar option on the glider would be nice as that helps.

8AH and 9AH 12v batteries in nominally the same form factor as 7AH
(varies a bit by manufacturer) have become available for $18-$30.
Last 8AH batteries I bought were $15. Guess I wonder why some are
still using 7AH batteries.

My LAK-12 has builtin boxes for two 12AH (or larger) batteries and
room for insulation;^)

Frank Whiteley

Hal wrote:


With a becker transponder, 302,303, Dittle radio, and pda 4700 I get
about 3 hours on one 7amp/hour battery. Most of the flight at 14k and
above. When I fly in congested areas altitude is lower but 3 hours
seems to be about all I get there also. Older batteries get less. I
also have a hook-up for PCAS but I was not using it this week (in
shop). The solar option on the glider would be nice as that helps.

Your setup sounds like it would have less than 1 amp draw, which would
give almost 6 hours off a new 7 AH battery. Have you measured the actual
draw? What is the battery voltage at the end of 3 hours?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* Sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

On Jul 4, 1:16*pm, Eric Greenwell wrote:
Hal wrote:

With a becker transponder, 302,303, Dittle radio, and pda 4700 I get
about 3 hours on one 7amp/hour battery. *Most of the flight at 14k and
above. *When I fly in congested areas altitude is lower but 3 hours
seems to be about all I get there also. Older batteries get less. *I
also have a hook-up for PCAS but I was not using it this week (in
shop). *The solar option on the glider would be nice as that helps.

Your setup sounds like it would have less than 1 amp draw, which would
give almost 6 hours off a new 7 AH battery. Have you measured the actual
draw? What is the battery voltage at the end of 3 hours?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "Transponders in Sailplanes"http://tinyurl.com/y739x4
* * * Sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org

Not very scientific but I go until the dittle radio starts blinking
then I switch to battery 2. Maybe I should look into where I am
buying the batteries. They are power sonic ps1270f1 purchased at a
local electronics store.

Hal wrote:
On Jul 4, 1:16 pm, Eric Greenwell wrote:
Hal wrote:

With a becker transponder, 302,303, Dittle radio, and pda 4700 I get
about 3 hours on one 7amp/hour battery. Most of the flight at 14k and
above. When I fly in congested areas altitude is lower but 3 hours
seems to be about all I get there also. Older batteries get less. I
also have a hook-up for PCAS but I was not using it this week (in
shop). The solar option on the glider would be nice as that helps.
Your setup sounds like it would have less than 1 amp draw, which would
give almost 6 hours off a new 7 AH battery. Have you measured the actual
draw? What is the battery voltage at the end of 3 hours?

Not very scientific but I go until the dittle radio starts blinking
then I switch to battery 2. Maybe I should look into where I am
buying the batteries. They are power sonic ps1270f1 purchased at a
local electronics store.

But first, measure the current drain of your panel, and measure the
capacity of your batteries. If you do get new batteries, fully charge
them and measure their capacity, so you know you got fresh ones.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* Sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org