Battery Question

All,
I purchased an 8 Amp-hour battery for use in my ASW-20 about 6 months
ago. I had been running a radio, ELT, 302/303 combination, and IPAQ
3800. With that combination my battery would last longer than I wanted
to be in the air; generally more than 5 hours.
I recently removed the 303 and added an SN10B with one meter, so the
electric instrumentation suite is now a radio, ELT, SN10 with one
meter, 302 and IPAQ 3800. At first I didn't notice any difference in
battery performance, but lately it seems the battery has been lasting
progressively shorter periods, and this past weekend the SN10 gave me a
low battery warning after only 2 hours in the air, and that was without
arming the ELT. I keep my battery on the charger on float whenever I'm
not flying, which means it stays on the charger all the time except on
weekends, and it's not even a year old.
Does anyone have a sense of whether I am facing a battery that is
failing, a short somewhere, or simply too many instruments on 1
battery? The battery is a PowerSonic 1280, and the charger is a
standard RR14650A gell cell automatic charger. I also don't have the
tech sheets on all the instruments to add up the current drain so I
can't calculate the expected performance from the battery.
Respectfully,

Phil,

Try using a voltmeter after the flight to confirm that the battery is
actually drawn down. Several people have had erronious low battery
reading on SN-10's

GB

wrote:
All,
I purchased an 8 Amp-hour battery for use in my ASW-20 about 6 months
ago. I had been running a radio, ELT, 302/303 combination, and IPAQ
3800. With that combination my battery would last longer than I wanted
to be in the air; generally more than 5 hours.
I recently removed the 303 and added an SN10B with one meter, so the
electric instrumentation suite is now a radio, ELT, SN10 with one
meter, 302 and IPAQ 3800. At first I didn't notice any difference in
battery performance, but lately it seems the battery has been lasting
progressively shorter periods, and this past weekend the SN10 gave me a
low battery warning after only 2 hours in the air, and that was without
arming the ELT. I keep my battery on the charger on float whenever I'm
not flying, which means it stays on the charger all the time except on
weekends, and it's not even a year old.
Does anyone have a sense of whether I am facing a battery that is
failing, a short somewhere, or simply too many instruments on 1
battery? The battery is a PowerSonic 1280, and the charger is a
standard RR14650A gell cell automatic charger. I also don't have the
tech sheets on all the instruments to add up the current drain so I
can't calculate the expected performance from the battery.
Respectfully,

You need to measure the battery voltage when it has been on charge for
enough time that you expect it will be fully charged. You said you were
using a float charger. If that's the case, then the voltage on float should
be about 13.8 to 13.9 volts - - the manufacturer has a table for correct
float voltage based on temperature. If the float charger is designed for gel
cells, then its output float voltage will be set somewhat lower than the
voltage AGM sealed lead acid battery requires for float. However, the
battery you have is most likely an AGM, not a gel-cell.

After the battery has been removed from charge for more than 30 minutes,
check the voltage again. With no load and room temperature, a fully charged
battery will have a voltage of about 12.8 volts. A half discharged battery
will be about 12.5 volts at no load.

In any case, you will never fully charge a sealed lead acid battery with a
voltage regulated charger designed to float charge the battery. The most you
can expect is about 80 to 85%. To fully charge the battery, you would need
to bring the voltage up to near 15 volts, but it cannot be left at this
voltage for a prolonged period as the battery will be overcharged and
eventually, damaged. Sealed batteries don't handle overcharging well.

A good automatic battery charger will account for this and switch over to a
lower maintenance charge after the battery is fully charged. If the battery
will not have a load on it while charging, the best charger is a 3 stage
that provides bulk, absorption, and float or maintenance.

all the best,

bumper




wrote in message
ups.com...
All,
I purchased an 8 Amp-hour battery for use in my ASW-20 about 6 months
ago. I had been running a radio, ELT, 302/303 combination, and IPAQ
3800. With that combination my battery would last longer than I wanted
to be in the air; generally more than 5 hours.
I recently removed the 303 and added an SN10B with one meter, so the
electric instrumentation suite is now a radio, ELT, SN10 with one
meter, 302 and IPAQ 3800. At first I didn't notice any difference in
battery performance, but lately it seems the battery has been lasting
progressively shorter periods, and this past weekend the SN10 gave me a
low battery warning after only 2 hours in the air, and that was without
arming the ELT. I keep my battery on the charger on float whenever I'm
not flying, which means it stays on the charger all the time except on
weekends, and it's not even a year old.
Does anyone have a sense of whether I am facing a battery that is
failing, a short somewhere, or simply too many instruments on 1
battery? The battery is a PowerSonic 1280, and the charger is a
standard RR14650A gell cell automatic charger. I also don't have the
tech sheets on all the instruments to add up the current drain so I
can't calculate the expected performance from the battery.
Respectfully,

I hate top posting in general, but it seems to fit here. Bumper has
noted very important points, and to add fuel to the fire, it is
important that the battery is designed for the intended service. The
only 1280 I see on the Power-Sonic sebsite is the PSH1280 which is
designed for UPS applications, and for 15 minute discharges of roughly
20 amps. I would not be at all surprised (they don't say) that just 2
or 3 of those will significantly reduce capacity. Your far more
reasonable discharge would be less severe, but I'd still guess it is
low on the number of cycles vs their more "traditional" designs.

On Sun, 11 Sep 2005 21:13:47 -0700, "bumper" wrote:

You need to measure the battery voltage when it has been on charge for
enough time that you expect it will be fully charged. You said you were
using a float charger. If that's the case, then the voltage on float should
be about 13.8 to 13.9 volts - - the manufacturer has a table for correct
float voltage based on temperature. If the float charger is designed for gel
cells, then its output float voltage will be set somewhat lower than the
voltage AGM sealed lead acid battery requires for float. However, the
battery you have is most likely an AGM, not a gel-cell.

After the battery has been removed from charge for more than 30 minutes,
check the voltage again. With no load and room temperature, a fully charged
battery will have a voltage of about 12.8 volts. A half discharged battery
will be about 12.5 volts at no load.

In any case, you will never fully charge a sealed lead acid battery with a
voltage regulated charger designed to float charge the battery. The most you
can expect is about 80 to 85%. To fully charge the battery, you would need
to bring the voltage up to near 15 volts, but it cannot be left at this
voltage for a prolonged period as the battery will be overcharged and
eventually, damaged. Sealed batteries don't handle overcharging well.

A good automatic battery charger will account for this and switch over to a
lower maintenance charge after the battery is fully charged. If the battery
will not have a load on it while charging, the best charger is a 3 stage
that provides bulk, absorption, and float or maintenance.

all the best,

bumper




wrote in message
oups.com...
All,
I purchased an 8 Amp-hour battery for use in my ASW-20 about 6 months
ago. I had been running a radio, ELT, 302/303 combination, and IPAQ
3800. With that combination my battery would last longer than I wanted
to be in the air; generally more than 5 hours.
I recently removed the 303 and added an SN10B with one meter, so the
electric instrumentation suite is now a radio, ELT, SN10 with one
meter, 302 and IPAQ 3800. At first I didn't notice any difference in
battery performance, but lately it seems the battery has been lasting
progressively shorter periods, and this past weekend the SN10 gave me a
low battery warning after only 2 hours in the air, and that was without
arming the ELT. I keep my battery on the charger on float whenever I'm
not flying, which means it stays on the charger all the time except on
weekends, and it's not even a year old.
Does anyone have a sense of whether I am facing a battery that is
failing, a short somewhere, or simply too many instruments on 1
battery? The battery is a PowerSonic 1280, and the charger is a
standard RR14650A gell cell automatic charger. I also don't have the
tech sheets on all the instruments to add up the current drain so I
can't calculate the expected performance from the battery.
Respectfully,

GeorgeB wrote:
I hate top posting in general, but it seems to fit here. Bumper has
noted very important points, and to add fuel to the fire, it is
important that the battery is designed for the intended service. The
only 1280 I see on the Power-Sonic sebsite is the PSH1280 which is
designed for UPS applications, and for 15 minute discharges of roughly
20 amps. I would not be at all surprised (they don't say) that just 2
or 3 of those will significantly reduce capacity. Your far more
reasonable discharge would be less severe, but I'd still guess it is
low on the number of cycles vs their more "traditional" designs.

According to the Powersonic Technical Manual

(http://www.power-sonic.com/techman.pdf)

their batteries are designed for cyclical use. The diagram on page 6
indicates 200 complete discharge cycles can be obtained before the
battery capacity reduces to 60%, or 400 discharges of one-half the
amphour capacity. The battery choice appears to be OK for glider use, so
I suspect the problem is as some other posters suggested: current drain
is higher than expected, a defective battery, improper charging, or even
erroneous voltage readings from the SN 10.
--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

X-no-archive: yes
In article , Eric Greenwell
writes
GeorgeB wrote:
I hate top posting in general, but it seems to fit here. Bumper has
noted very important points, and to add fuel to the fire, it is
important that the battery is designed for the intended service. The
only 1280 I see on the Power-Sonic sebsite is the PSH1280 which is
designed for UPS applications, and for 15 minute discharges of roughly
20 amps. I would not be at all surprised (they don't say) that just 2
or 3 of those will significantly reduce capacity. Your far more
reasonable discharge would be less severe, but I'd still guess it is
low on the number of cycles vs their more "traditional" designs.

According to the Powersonic Technical Manual

(http://www.power-sonic.com/techman.pdf)

their batteries are designed for cyclical use. The diagram on page 6
indicates 200 complete discharge cycles can be obtained before the
battery capacity reduces to 60%, or 400 discharges of one-half the
amphour capacity. The battery choice appears to be OK for glider use, so
I suspect the problem is as some other posters suggested: current drain
is higher than expected, a defective battery, improper charging, or even
erroneous voltage readings from the SN 10.

The only way to find out what the capacity of a battery may be is to
either do a timed discharge at a fixed current (tedious) or use an
instrument that measures the capacity and compensates for temperature. I
use such a device but they are expensive. My meter is now priced at
332.07 USD (185.00 UKP), so borrow one if you can.

For more details go to http://www.actmeters.com/actmeters.htm
and look on 'quick product index' for 'New GOLD-IBT Intelligent Battery
Tester'

Tim Newport-Peace

"Indecision is the Key to Flexibility."

wrote:
All,
I purchased an 8 Amp-hour battery for use in my ASW-20 about 6 months
ago. I had been running a radio, ELT, 302/303 combination, and IPAQ
3800. With that combination my battery would last longer than I wanted
to be in the air; generally more than 5 hours.
I recently removed the 303 and added an SN10B with one meter, so the
electric instrumentation suite is now a radio, ELT, SN10 with one
meter, 302 and IPAQ 3800. At first I didn't notice any difference in
battery performance, but lately it seems the battery has been lasting
progressively shorter periods, and this past weekend the SN10 gave me a
low battery warning after only 2 hours in the air, and that was without
arming the ELT. I keep my battery on the charger on float whenever I'm
not flying, which means it stays on the charger all the time except on
weekends, and it's not even a year old.
Does anyone have a sense of whether I am facing a battery that is
failing, a short somewhere, or simply too many instruments on 1
battery?

Borrow or buy a digital voltmeter (they aren't expensive) with at least
a 1 amp DC current scale, and measure the actual drain on your battery.
That will give you a good idea of what your battery life should be, and
if there is a problem with too high a current drain from one of the
instruments.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

wrote in message
ups.com...
All,
I purchased an 8 Amp-hour battery for use in my ASW-20 about 6 months
ago. I had been running a radio, ELT, 302/303 combination, and IPAQ
3800. With that combination my battery would last longer than I wanted
to be in the air; generally more than 5 hours.
I recently removed the 303 and added an SN10B with one meter, so the
electric instrumentation suite is now a radio, ELT, SN10 with one
meter, 302 and IPAQ 3800.

At first I didn't notice any difference in
battery performance, but lately it seems the battery has been lasting
progressively shorter periods, and this past weekend the SN10 gave me a
low battery warning after only 2 hours in the air, and that was without
arming the ELT.
snip

The progressively-shorter periods would indicate to me that the battery is
deteriorating.
Yep, even if it's pretty new

PowerSonic is a pretty good brand, but when I was in the alarm industry, we
went through a period where the PowerSonics were being sworn at by all the
techs, because they were being replaced so often. Six months later, it
wasn't a problem anymore. Probably just a single bad pallet. It could be
you just got a battery that didn't live very long.

Tim Ward

Tim,

Small world, I have an alarm company in Vallejo, CA (Morgan Alarm), though I
seldom visit, as my son and daughter-in-law are allowing me to mostly
retire.

We experienced the same QC issues with both Powersonic and Yuasa. Now, with
most of the small AGM sealed lead-acid batteries coming from China, I
suspect several brands are coming from the same factory. Cases and fittings
appear identical. We've had good results with ELK brand, but even so, when
you use 200+ per month, there's the occasional early failure.

We replace our customers batteries every 5 years, though they can go longer.
For glider use, I suggest replacing them at 3 years. Cheap insurance.

bumper

"Tim Ward" wrote in message
link.net...

wrote in message
ups.com...
All,
I purchased an 8 Amp-hour battery for use in my ASW-20 about 6 months
ago. I had been running a radio, ELT, 302/303 combination, and IPAQ
3800. With that combination my battery would last longer than I wanted
to be in the air; generally more than 5 hours.
I recently removed the 303 and added an SN10B with one meter, so the
electric instrumentation suite is now a radio, ELT, SN10 with one
meter, 302 and IPAQ 3800.

At first I didn't notice any difference in
battery performance, but lately it seems the battery has been lasting
progressively shorter periods, and this past weekend the SN10 gave me a
low battery warning after only 2 hours in the air, and that was without
arming the ELT.
snip

The progressively-shorter periods would indicate to me that the battery is
deteriorating.
Yep, even if it's pretty new

PowerSonic is a pretty good brand, but when I was in the alarm industry,
we
went through a period where the PowerSonics were being sworn at by all the
techs, because they were being replaced so often. Six months later, it
wasn't a problem anymore. Probably just a single bad pallet. It could be
you just got a battery that didn't live very long.

Tim Ward

wrote in message
ups.com...

You didn't say much about your charger. If it is a cheap one-stage
"trickle charger", look no further. Go out and buy yourself a good 3-stage
float charger (you will pay about $50.00) and a new battery. Overcharging by a
few tenths of a volt can easily ruin a battery in the timeframe you mentioned.
As others have mentioned, it is also possible that you just got unlucky and got
a bad one.

Vaughn