At 01:59 17 November 2018, JS wrote:
On Friday, November 16, 2018 at 5:45:04 PM UTC-8, Michael Opitz
wrote:
At 00:25 17 November 2018, Mike the Strike wrote:
On Friday, November 16, 2018 at 11:45:04 AM UTC-7, Dave
Walsh
wrote:
At 17:37 16 November 2018, Emir Sherbi wrote:
A plastic container with concrete?

Eh? What is wrong with just leaving the existing battery in
the
tail? I've several "dead" lead acid batteries from the days I
owned a DG400: they're now nearly 20 years old, all are
perfect physically, no swelling, no leakage....

Yep - my Discus 2 tail battery sat unused in the Arizona heat
for
ten years
and remained intact with no leaks. Using that weight is a lot
easier than
reducing the mass ahead of the CG!

Mike

When I went to a LiFePo battery for my main power because of
the
current drain from the modern instruments, I found that the lead
acid tail battery didn't provide enough power to last as long as
I'd
like for a true backup to last. My solution was to buy a second
LiFePo battery and install it next to the main one in the wheel
well
area battery compartment in my D-2b. I have looked for a
LiFePo
battery that fits in the tail fin, but the only ones that I found
were
frightfully expensive. I also imagine that a LiFePo tail battery
would
be a lot lighter than a lead-acid one as well, and that would
necessitate adding other weights somehow. What I did, was to
find
a used solid brass tail wheel hub on the German want ads, and
utilized that to replace the SH plastic hub. This moves the tail
weight to a lot lower point on the boom, which is a good thing in
case of a ground loop. The only bad thing is that the glider
weight
and balance is now set up just for me, and if I want to let a
lighter
person fly it, then we have to add seat weights. If I were still
using
the tail battery for weight, then all I'd have to do would be to
remove it, and the lighter pilot wouldn't have to deal with extra
weights in the cockpit.

RO

This $50 3AH Bioenno LiFePO4 in a box made from paint stirring
sticks, foam
and heat shrink, also including two 1kg lead weights fits in the
Schleicher
tail battery compartment. Two batteries would fit, but may not be
heavy
enough.
https://www.bioennopower.com/collect...eries-lifepo4-
batteries/products/copy-of-12v-3ah-lfp-battery-pvc-blf-1203a
The two power connectors are wired in parallel.
Jim

Thanks, I'll have a look.

RO