glider battery duration problems

GC wrote, On 10/23/2013 2:18 AM:
On 8/10/2013 04:17, son_of_flubber wrote:

The internal "completely discharged" capacity of a Shorai LFX is 1/3
the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah
cells internally. But the cells are capable of 80% discharge without
damage and while retaining more cranking ability. As such, the USABLE
capacity(or "reserve capacity") of an LFX18 12V battery is on or very
near par with 18AHr-rated lead acid batteries, while providing
superior cranking performance and a vast reduction in weight. The
Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows
users to compare a very different technology from lead-acid, but on a
close apples-to-apples basis when making a choice.

So they say. In the famous words of Miss Mandy Rice-Davies "They would
say that wouldn't they".

BTW - how big is "vast"?

According to Shorai, it's about a 5:1 weight reduction. That's also a
clue to why they aren't good for energy storage: there just isn't enough
material inside the case to store the energy you expect for the
"[equivalent] amp hour rating". A typical Li-Fe battery will weigh about
half of what an SLA weighs for a given amp hour capacity.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On Wednesday, October 23, 2013 5:18:15 AM UTC-4, GC wrote:
On 8/10/2013 04:17, son_of_flubber wrote:



The internal "completely discharged" capacity of a Shorai LFX is 1/3

the rated "PBeq" capacity. For example, the LFX18 12V series have 6Ah

cells internally. But the cells are capable of 80% discharge without

damage and while retaining more cranking ability. As such, the USABLE

capacity(or "reserve capacity") of an LFX18 12V battery is on or very

near par with 18AHr-rated lead acid batteries, while providing

superior cranking performance and a vast reduction in weight. The

Shorai PBeq AHr (lead-acid equivalent) rating system therefore allows

users to compare a very different technology from lead-acid, but on a

close apples-to-apples basis when making a choice.



So they say. In the famous words of Miss Mandy Rice-Davies "They would

say that wouldn't they".

GC

Shori confirmed by email that they only make batteries for "starting applications". We knew that but it is good that they admit it.

The marketing people always lie and for that reason I do not judge a battery by its website.

Maybe we will see some new products come up for Spring.

On Wednesday, October 2, 2013 11:46:32 AM UTC-6, John Marshall wrote:
I need advice about the best choice of batteries for an asg 29e. lithium

ion would be outside manufacturer's remit and the insurer's plus too many

risks-the fuel tank is directly above the battery housings. I would like

something with at least 9 amp hours, whether gel cell or mh.

Maybe this is way off track - but maybe you have a transponder ?
if most transponders are not specially programmed (set up) they will
run all the time - they are "on" all of the time - drawing power even
when your panel read out says "off" - I had that problem in 2 gliders -
EB28 Edition - another solution to check this power loss is to unplug
the transponder and see if that solves the problem - if it does then
get out your manual and find out how to change the settings - good luck

On Wednesday, October 2, 2013 11:46:32 AM UTC-6, John Marshall wrote:
I need advice about the best choice of batteries for an asg 29e. lithium

ion would be outside manufacturer's remit and the insurer's plus too many

risks-the fuel tank is directly above the battery housings. I would like

something with at least 9 amp hours, whether gel cell or mh.

from another posting -

I did, however, get behind my panel last week and changed out my master
switch for one more substantial in current capability and have experienced a
major improvement in function of my equipment. The switch that was
installed when I bought the glider was adequate for the CAI302 and the
MicroAir 760 but, after installing a Trig transponder, a Dell Steak and a
Zaon MRX, all operated from the same bus, the current capacity of the master
switch was the limiting factor. After two flights with the new master
switch installed it would appear that the problem is solved.

On Wednesday, October 23, 2013 8:15:26 PM UTC-4, wrote:
if most transponders are not specially programmed (set up) they will
run all the time - they are "on" all of the time - drawing power even
when your panel read out says "off"

Say what ? A transponder should draw very little power except
when it is transmitting, which it only does when interrogated.
A Mode S transponder draws less than Mode C as it responds to
selective (fewer) interrogations (yes Daryll, I'm simplifying).
The only notable draw for a transponder installation would be a
poor quality encoder (older models have power-hungry heaters
rather than temperature-compensated altitude transducers);
should not be a problem for modern units...

Perhaps you can email me offline make/model of the setup
which gave you power problems?

Hope that helps,
Best Regards, Dave

When I turn my master switch off, power is removed from the DC bus. My
transponder is powered from the bus.

Switch off = no power drain.


wrote in message
...
On Wednesday, October 2, 2013 11:46:32 AM UTC-6, John Marshall wrote:
I need advice about the best choice of batteries for an asg 29e. lithium

ion would be outside manufacturer's remit and the insurer's plus too many

risks-the fuel tank is directly above the battery housings. I would like

something with at least 9 amp hours, whether gel cell or mh.

Maybe this is way off track - but maybe you have a transponder ?
if most transponders are not specially programmed (set up) they will
run all the time - they are "on" all of the time - drawing power even
when your panel read out says "off" - I had that problem in 2 gliders -
EB28 Edition - another solution to check this power loss is to unplug
the transponder and see if that solves the problem - if it does then
get out your manual and find out how to change the settings - good luck

Mode C Transponders I've used have a heater in the separate altitude encoder. This is a factor whenever the unit is turned on.
Jim