Trig TT21 Transponder ... reports?

"Eric Greenwell" wrote

The Pro-Peak appears to be identical to the Multiplex LN5014 that I
already have. I like the charger, it works well, it's simple to use, and
is very handy for the glider and other purposes, but I still wish for one
that charged 12 volt SLA batteries at 14.6 volts instead of 14.0, and
would discharge at 1 amp or more, instead of only 0.4 amps.

Maybe someone has another recommendation?

MMmmmm. I am not so sure why you would want to go for more charge voltage.
From what I read, that higher voltage is very harmful to SLA batteries.
Same reading says not to use a charger meant for car batteries (flooded lead
acid) because of the higher voltage hurting the sealed versions.

I have never used a multi stage charger. I only use a small float charger,
which I normally charge and leave on floating for 3 or so days, then remove
it until a month later, then charge with the float charger again for one
day.

The thing I have found that kills SLA quicker than crap, is leaving them
sitting around in a low charge state. That, and do not use an adapter or
jumpers to charge it from a running car electrical system. I once destroyed
a battery in one weekend, using that idea. After that, I read about the
higher charge being a "bad thing" and now I believe it.
--
Jim in NC

On Aug 24, 4:11*pm, "Morgans" wrote:
"Eric Greenwell" wrote

The Pro-Peak appears to be identical to the Multiplex LN5014 that I
already have. I like the charger, it works well, it's simple to use, and
is very handy for the glider and other purposes, but I still wish for one
that charged 12 volt SLA batteries at 14.6 volts instead of 14.0, and
would discharge at 1 amp or more, instead of only 0.4 amps.

Maybe someone has another recommendation?

*MMmmmm. *I am not so sure why you would want to go for more charge voltage.
From what I read, that higher voltage is very harmful to SLA batteries.
Same reading says not to use a charger meant for car batteries (flooded lead
acid) because of the higher voltage hurting the sealed versions.

I have never used a multi stage charger. *I only use a small float charger,
which I normally charge and leave on floating for 3 or so days, then remove
it until a month later, then charge with the float charger again for one
day.

The thing I have found that kills SLA quicker than crap, is leaving them
sitting around in a low charge state. *That, and do not use an adapter or
jumpers to charge it from a running car electrical system. *I once destroyed
a battery in one weekend, using that idea. *After that, I read about the
higher charge being a "bad thing" and now I believe it.
--
Jim in NC

High flat voltage is a bad thing. The right voltage during absorption
charge mode (which Eric is talking about) helps charge the battery in
a minimal time and is not bad - it is the recommended process for
these batteries.

Darryl

On 8/24/2010 4:11 PM, Morgans wrote:
"Eric wrote


The Pro-Peak appears to be identical to the Multiplex LN5014 that I
already have. I like the charger, it works well, it's simple to use, and
is very handy for the glider and other purposes, but I still wish for one
that charged 12 volt SLA batteries at 14.6 volts instead of 14.0, and
would discharge at 1 amp or more, instead of only 0.4 amps.

Maybe someone has another recommendation?

MMmmmm. I am not so sure why you would want to go for more charge voltage.
From what I read, that higher voltage is very harmful to SLA batteries.
Same reading says not to use a charger meant for car batteries (flooded lead
acid) because of the higher voltage hurting the sealed versions.

Our SLA battery specifications for cyclic charging (the way we use our
glider batteries) typically call for about 14.7 volts that's held until
the current drops to a few percent of the rated capacity. At that point,
the voltage should be dropped to about 13.6 volts, or the charger
removed. It ensures the quickest full charge and maximum battery life.
Flooded batteries usually require a lower voltage for the same
conditions. Older style car chargers tended to overcharge, which the
flooded batteries tolerate well (the water just got lower), but not the
SLAs, and that's likely the reason for the prohibition you read.
I have never used a multi stage charger. I only use a small float charger,
which I normally charge and leave on floating for 3 or so days, then remove
it until a month later, then charge with the float charger again for one
day.

Your system is fine, but a 3 stage charger matched to your battery will
do the job quicker. It sounds like you don't need that, but pilots that
fly several days in a row have to use something faster than a float
charger, and a multi-stage charger does the job. Or, they have to have
several batteries on charge so they can put a fully charged one in the
glider each day.
The thing I have found that kills SLA quicker than crap, is leaving them
sitting around in a low charge state.
This is poor practice for any lead-acid battery, but the SLAs are
generally relatively tolerant of it, if you have a good charger. By
"tolerant", I mean you can let it sit for a few weeks ocasionally,
mostly discharged, and it won't affect the life noticeably. A float
charger may not have enough voltage to remove the sulphation that occurs
when sitting around with a low charge, and that is one reason prefer the
~14.7 volt charge.
That, and do not use an adapter or
jumpers to charge it from a running car electrical system. I once destroyed
a battery in one weekend, using that idea. After that, I read about the
higher charge being a "bad thing" and now I believe it.

The car charge regulator is under the hood, adjusting the charge voltage
for the temperatures there (and for a flooded battery with it's lower
voltage requirement), and it might not actually produce enough voltage
to fully charge an SLA that's sitting outside the engine compartment in
cooler temperatures. I suspect your battery had undercharge problems,
not overcharge.

--

Eric Greenwell - Washington State, USA (netto to net to email me)

- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm http://tinyurl.com/yb3xywl

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what you need to know tinyurl.com/yfs7tnz