AGM Batteries

Any current thoughts on AGM batteries?

I tried a Concorde 35AXC about 8 years ago. It lasted about 30 months
for me. Wet batteries seem to last around 4 years.

However, there was some corrosion damage from the wet battery last
annual, and so I'm rethinking the AGM option. I might be willing to
trade some battery lifetime to avoid potential airframe issues.

Anyone have a preference on Concorde vs. Gill?

tia

"DA" == Dave Anderer writes:
DA Anyone have a preference on Concorde vs. Gill?

Yes. I've used both a Gill and Concorde in my Aircoupe and the
Concorde outperforms the Gill. I'll never buy a Gill again, they
don't last.
--
The church tries to save sinners, but science seeks to stop their
manufacture.
~ Elbert Hubbard

* * DA Anyone have a preference on Concorde vs. Gill?

Yes. I've used both a Gill and Concorde in my Aircoupe and the
Concorde outperforms the Gill. *I'll never buy a Gill again, they
don't last.
--
The church tries to save sinners, but science seeks to stop their
manufacture.
*~ Elbert Hubbard

I'll second that - The Concordes are noticeably better.

I haven't tried an AGM Aviation battery, but recently had a bad
experience buying some AGMs for an electric scooter. Turns out the
brand new "Deep Cycle" AGMs were not even equal to the worst of the
batteries I was replacing (same size/shape/AH rating, but a different
brand that appear to be unavailable in the US).

David Johnson

Dave Anderer wrote:


Anyone have a preference on Concorde vs. Gill?


If the experiences of those on the Cherokee Pilots Assoc. forum are any
measure, the sealed Gill is bad news. There are quite a few folks that have
been flying around for more than 5 yrs. on their Concorde sealed batteries.

Initially, both Gill and Concorde had teething problems, but Concorde
seems to have worked them out. On the other hand, we see repeated posts (as
recently as a few months ago) that the Gills are dying within 12 months or
less. Gill is happy to replace them, but the replacements don't last any
longer. They know they have a problem, but apparently haven't been able to
fix it.

I'm planning on going with a sealed battery when my current wet cell Gill
dies. It'll definitely be a Concorde.

John Galban=====N4BQ (PA28-180)

--
Message posted via http://www.aviationkb.com

Agreed!

55 months on our Concord.. working great..

I detect it's gettin a bit "soft" I think. open voltage down a
little if been sitting a week or so... maybe not....

The test at annual next month will tell the tale...

Dave


On Mon, 10 Mar 2008 23:25:11 GMT, "JGalban via AviationKB.com"
u32749@uwe wrote:

Dave Anderer wrote:


Anyone have a preference on Concorde vs. Gill?


If the experiences of those on the Cherokee Pilots Assoc. forum are any
measure, the sealed Gill is bad news. There are quite a few folks that have
been flying around for more than 5 yrs. on their Concorde sealed batteries.

Initially, both Gill and Concorde had teething problems, but Concorde
seems to have worked them out. On the other hand, we see repeated posts (as
recently as a few months ago) that the Gills are dying within 12 months or
less. Gill is happy to replace them, but the replacements don't last any
longer. They know they have a problem, but apparently haven't been able to
fix it.

I'm planning on going with a sealed battery when my current wet cell Gill
dies. It'll definitely be a Concorde.

John Galban=====N4BQ (PA28-180)

I hate rebuilding the battery box every few years. It's getting
pretty thin!! So I love the RG batteries.

I'm getting about 30 months too.

Check your bus voltage. If it's too high, the battery will
take it in the shorts.

Bill Hale BPPP instructor


On Mar 10, 11:46*am, Dave Anderer wrote:
Any current thoughts on AGM batteries?

I tried a Concorde 35AXC about 8 years ago. *It lasted about 30 months
for me. *Wet batteries seem to last around 4 years.

However, there was some corrosion damage from the wet battery last
annual, and so I'm rethinking the AGM option. *I might be willing to
trade some battery lifetime to avoid potential airframe issues.

Anyone have a preference on Concorde vs. Gill?

tia

" writes:

I hate rebuilding the battery box every few years. It's getting
pretty thin!! So I love the RG batteries.

When I put a battery in a car; I first pour baking soda in the tray and
mix it w/a little water into a paste.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

AGM is the best thing since sliced bread...
You do need to make sure the charge voltage is set properly for the
AGM (lower than for flooded cell)...

denny

On Mar 12, 4:03*pm, Peter wrote:
Denny wrote

AGM is the best thing since sliced bread...
You do need to make sure the charge voltage is set properly for the
AGM (lower than for flooded cell)...

denny

I didn't know that. How much lower? Mine is 28.0V.

Well, my nominal 12V system is set at 13.4 V during flight/charging,
and my battery maintainer (not charger) puts out a regulated 12.6 V
(as measured on a Fluke meter) and my AGM battery is 3 years and still
acts like it is brand new... If you use a so called trickle charger,
check the trickle voltage, if it is more than 12.6 it will hurt the
battery in the long run...

In general, the AGM have thinner plates with closer spacing that do
not tolerate the high charging currents that a flooded cell will
take... Lowering the charging voltage lowers the charging current...
It simply means that it takes bit longer to recharge after starting,
etc... Not a big deal, and in return you get the much faster cranking
and no spilling of the AGM battery...
So, extrapolating for the charging voltage in flight, I would suggest
26.5 volts... And I would consider adding a charge maintainer for
sitting idle (stops the plates from sulfating) that puts out something
near 24.5 volts......

denny

That's not QUITE true, according to the Concorde engineer that helped me
write the series of Kitplanes articles on AGM charging.

The AGM chemistry likes to be cycled. That is, the battery likes to be
taken up to 13.4 volts, allowed to self-discharge back down to 12.6, back up
to 13.4 and so forth. The cycle time is measured in days or weeks,
depending on how much "keep alive" circuits (clocks, radio memories, etc.)
are sucking on an "off" battery.

Jim




So, extrapolating for the charging voltage in flight, I would suggest
26.5 volts... And I would consider adding a charge maintainer for
sitting idle (stops the plates from sulfating) that puts out something
near 24.5 volts......

denny