Interesting behavior from PowerSonic battery

Steve Leonard wrote, On 5/23/2013 9:13 AM:
On Tuesday, May 21, 2013 4:32:29 PM UTC-5, 2G wrote: This is called
"cell reversal" and does occassionally happen. My question is why do
you think that you need a 14V battery? All modern aviation
electronics is designed to operate on a wide range of input voltage.
This is accomplished by a circuit called a "dc-dc converter" that
boosts the input voltage to a higher, regulated, internal voltage.
Tom

Well, 2G, where do you draw the line on "Modern" avionics? MicroAir
radio? Becker 3201 radio? Becker 4201 radio? Filser ATR500? I
have seen all of the above "crap out" on a 12 volt battery when my
Cambridge computer and nav keep on working.

Be happy with your 12 volt system, and don't be diss-ing on me for my
14 volt system, OK?

The Becker AR4201 is a "modern" radio, meeting the standard requirements
to transmit and receive at 10 volts. But, if a 12 volt battery has
dropped below 11 volts, it has so little energy left, it may not be able
to operate the 4201 in transmit mode; however, it should still receive
properly. If it won't receive with voltages between 10 and 11 volts, it
isn't operating properly, and I would send it in for repair.

The Cambridge computer and Nav can work on even lower voltages than the
10 volt specification for a transceiver, so they would work longer than
the radios.

The AR3201 is also a "modern" radio, and has the same voltage operating
specifications as the AR4201. Ditto for the ATR500. The Microair, at
least the earlier versions (don't know about the latest), is not a
"modern" radio, and has a much more limited voltage operating range than
the ATR500, AR3201, and AR4201.

Many thousands of pilots have (and still are) successfully operated
these very popular radios on 12 volts for over two decades. Since you've
had problems with all three radios that thousands of other pilots don't,
perhaps your installation was causing it; Possibly, your 12 volt battery
capacity was inadequate (battery too small or in poor condition), and
you simple ran out of charge. Adding a 14 volt battery to a marginal 12
volt system would increase the battery capacity, allowing you run longer.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

On Thursday, May 23, 2013 1:00:50 PM UTC-5, Eric Greenwell wrote:

The Becker AR4201 is a "modern" radio, meeting the standard requirements to transmit and receive at 10 volts. But, if a 12 volt battery has dropped below 11 volts, it has so little energy left, it may not be able to operate the 4201 in transmit mode; however, it should still receive properly. If it won't receive with voltages between 10 and 11 volts, it isn't operating properly, and I would send it in for repair. The Cambridge computer and Nav can work on even lower voltages than the 10 volt specification for a transceiver, so they would work longer than the radios. The AR3201 is also a "modern" radio, and has the same voltage operating specifications as the AR4201. Ditto for the ATR500. The Microair, at least the earlier versions (don't know about the latest), is not a "modern" radio, and has a much more limited voltage operating range than the ATR500, AR3201, and AR4201. Many thousands of pilots have (and still are) successfully operated these very popular radios on 12 volts for over two decades. Since you've had problems with all three radios that thousands of other pilots don't, perhaps your installation was causing it; Possibly, your 12 volt battery capacity was inadequate (battery too small or in poor condition), and you simple ran out of charge. Adding a 14 volt battery to a marginal 12 volt system would increase the battery capacity, allowing you run longer. -- Eric Greenwell - Washington State, USA

I also have Terra TX-720s (I know. ANCIENT. But, they work). I also know that most people running 12 volt batteries carry a second and even a third 12 volt battery as "backups". Some have even more than that. I have a single 14 volt battery in most everything I fly. And my one 14 volt battery is lighter than your two or three or four 12 volt batteries. I would much rather have one system that is reliable and will work all the time than several that will work, but must be changed during a long flight.

All of the above noted radio crap-outs have been lack of transimission from one of those radios hooked to a 12 volt battery some time into the flight. They all still receive just fine. Not all have been me personally. So, my crappy wiring isn't the fault in all of these instances. :-)

Feel free to continue enjoying the added security you feel with multiple 12 volt batteries and the associated wiring, switches, fuses, etc. Just like so many people need to have backup loggers becasue what they have sometimes fails. Me? I have a Cambridge Model 20. Has never failed. Other things are newer, and some may be better, but none that I am aware of have had fewer bugs or lockups in flight.

My favorite quote about a backup system, and maybe it was just how I chose to read it, was from A.J. Smith. Talking about the AS-W12 and the addition of a second drag chute, in case there was an issue with the primary. He said "That way, you get TWO failures per flight."

Now, lets all just get our batteries charged and get ready for a fun weekend of flying, OK?

Steve Leonard wrote, On 5/23/2013 11:28 AM:
My favorite quote about a backup system, and maybe it was just how I
chose to read it, was from A.J. Smith. Talking about the AS-W12 and
the addition of a second drag chute, in case there was an issue with
the primary. He said "That way, you get TWO failures per flight."

AJ isn't around to ask about it, but you why don't ask a skydiver about
why they bother with a reserve parachute ;^)

My point is, there are several reasons to have more than one battery,
and none of them are related to how much voltage a "modern" radio needs.

For your setup, with a TX 720, 14 volts may be a good choice, as it's
voltage input is specified at 13.75 volts. It was not designed to the
same requirements that have been in effect for certified radios for over
20 years, which require operation over a wide voltage range.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

Sky divers 'bother' with a reserve parachute because the law requires it.
BASE jumpers, outlaws by nature, don't bother because there's no time for a
reserve.


"Eric Greenwell" wrote in message
...
Steve Leonard wrote, On 5/23/2013 11:28 AM:
My favorite quote about a backup system, and maybe it was just how I
chose to read it, was from A.J. Smith. Talking about the AS-W12 and
the addition of a second drag chute, in case there was an issue with
the primary. He said "That way, you get TWO failures per flight."

AJ isn't around to ask about it, but you why don't ask a skydiver about
why they bother with a reserve parachute ;^)

My point is, there are several reasons to have more than one battery, and
none of them are related to how much voltage a "modern" radio needs.

For your setup, with a TX 720, 14 volts may be a good choice, as it's
voltage input is specified at 13.75 volts. It was not designed to the same
requirements that have been in effect for certified radios for over 20
years, which require operation over a wide voltage range.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

Dan Marotta wrote, On 5/24/2013 8:37 AM:
Sky divers 'bother' with a reserve parachute because the law requires it.

Not the ones I've talked to.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl