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And Speaking of Batteries and Center of Gravity



 
 
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  #1  
Old November 16th 18, 05:24 PM posted to rec.aviation.soaring
Dan Marotta
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Posts: 4,601
Default And Speaking of Batteries and Center of Gravity

I'm thinking of eliminating the tail battery in my Stemme but need the
weight for proper balance.Â* I know I could replace it with pure lead,
but that's a lot of work so I've come up with a plan that would be more
satisfying and I would like comments and/or suggestions.

My thought is to discharge the battery fully.Â* It's a standard AGM that
everyone uses.Â* Then drill a couple of holes in the case and flush out
the electrolyte a couple of times with water.Â* Then fill the case up
with a highly saturated solution of NaHCO3, baking soda if I have the
formula correctly, and completely neutralize any remaining acid.Â* A
final flush with pure water, let it dry out, and finally, I could add
just about anything inert to bump the weight back up to what it was, and
plug the holes.Â* Voila!Â* A perfectly sized ballast weight.

Comments?Â* Have I missed anything?
--
Dan, 5J
  #2  
Old November 16th 18, 05:35 PM posted to rec.aviation.soaring
Matt Herron Jr.
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Posts: 548
Default And Speaking of Batteries and Center of Gravity

On Friday, November 16, 2018 at 9:24:20 AM UTC-8, Dan Marotta wrote:
I'm thinking of eliminating the tail battery in my Stemme but need the
weight for proper balance.Â* I know I could replace it with pure lead,
but that's a lot of work so I've come up with a plan that would be more
satisfying and I would like comments and/or suggestions.

My thought is to discharge the battery fully.Â* It's a standard AGM that
everyone uses.Â* Then drill a couple of holes in the case and flush out
the electrolyte a couple of times with water.Â* Then fill the case up
with a highly saturated solution of NaHCO3, baking soda if I have the
formula correctly, and completely neutralize any remaining acid.Â* A
final flush with pure water, let it dry out, and finally, I could add
just about anything inert to bump the weight back up to what it was, and
plug the holes.Â* Voila!Â* A perfectly sized ballast weight.

Comments?Â* Have I missed anything?
--
Dan, 5J


thats less work than a lump of lead and a block of foam???
  #3  
Old November 16th 18, 05:37 PM posted to rec.aviation.soaring
Emir Sherbi
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Posts: 64
Default And Speaking of Batteries and Center of Gravity

A plastic container with concrete?
  #4  
Old November 17th 18, 03:24 AM posted to rec.aviation.soaring
Dan Marotta
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Posts: 4,601
Default And Speaking of Batteries and Center of Gravity

Lighter than lead.

On 11/16/2018 10:37 AM, Emir Sherbi wrote:
A plastic container with concrete?


--
Dan, 5J
  #5  
Old November 17th 18, 03:23 AM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default And Speaking of Batteries and Center of Gravity

Yeah, it'd be fun and I wouldn't have to source the lead, melt it, and
mold it to the right size/shape.

On 11/16/2018 10:35 AM, Matt Herron Jr. wrote:
On Friday, November 16, 2018 at 9:24:20 AM UTC-8, Dan Marotta wrote:
I'm thinking of eliminating the tail battery in my Stemme but need the
weight for proper balance.Â* I know I could replace it with pure lead,
but that's a lot of work so I've come up with a plan that would be more
satisfying and I would like comments and/or suggestions.

My thought is to discharge the battery fully.Â* It's a standard AGM that
everyone uses.Â* Then drill a couple of holes in the case and flush out
the electrolyte a couple of times with water.Â* Then fill the case up
with a highly saturated solution of NaHCO3, baking soda if I have the
formula correctly, and completely neutralize any remaining acid.Â* A
final flush with pure water, let it dry out, and finally, I could add
just about anything inert to bump the weight back up to what it was, and
plug the holes.Â* Voila!Â* A perfectly sized ballast weight.

Comments?Â* Have I missed anything?
--
Dan, 5J

thats less work than a lump of lead and a block of foam???


--
Dan, 5J
  #6  
Old November 17th 18, 05:36 AM posted to rec.aviation.soaring
Mike C
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Posts: 337
Default And Speaking of Batteries and Center of Gravity

On Friday, November 16, 2018 at 8:23:25 PM UTC-7, Dan Marotta wrote:
Yeah, it'd be fun and I wouldn't have to source the lead, melt it, and
mold it to the right size/shape.

On 11/16/2018 10:35 AM, Matt Herron Jr. wrote:
On Friday, November 16, 2018 at 9:24:20 AM UTC-8, Dan Marotta wrote:
I'm thinking of eliminating the tail battery in my Stemme but need the
weight for proper balance.Â* I know I could replace it with pure lead,
but that's a lot of work so I've come up with a plan that would be more
satisfying and I would like comments and/or suggestions.

My thought is to discharge the battery fully.Â* It's a standard AGM that
everyone uses.Â* Then drill a couple of holes in the case and flush out
the electrolyte a couple of times with water.Â* Then fill the case up
with a highly saturated solution of NaHCO3, baking soda if I have the
formula correctly, and completely neutralize any remaining acid.Â* A
final flush with pure water, let it dry out, and finally, I could add
just about anything inert to bump the weight back up to what it was, and
plug the holes.Â* Voila!Â* A perfectly sized ballast weight.

Comments?Â* Have I missed anything?
--
Dan, 5J

thats less work than a lump of lead and a block of foam???


--
Dan, 5J


Lead shot/epoxy slurry mix can be molded into about any shape and is relatively easy to source. Used it to make tail weights for my RS15.

Also lead wool can be found in hardware stores and is easily melted with a propane torch.

Mike (4)
  #7  
Old November 17th 18, 09:30 AM posted to rec.aviation.soaring
Jim White[_3_]
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Posts: 286
Default And Speaking of Batteries and Center of Gravity

At 05:36 17 November 2018, Mike C wrote:

Lead shot/epoxy slurry mix can be molded into about any shape and is
relati=
vely easy to source. Used it to make tail weights for my RS15.

Also lead wool can be found in hardware stores and is easily melted with

a
=
propane torch.

Mike (4)

In the UK one can buy lead flashing from the builders merchant. This is a
roll of thin lead sheet about 6 inches wide. Just fold it several times
lengthwise into a paperback shaped weight, wrap with duct tape and drop it
in the slot. About ten minutes work.

  #8  
Old November 16th 18, 05:37 PM posted to rec.aviation.soaring
Pat
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Posts: 4
Default And Speaking of Batteries and Center of Gravity

Don't forget to take into account the new definition of a kilogram.
  #9  
Old November 17th 18, 03:23 AM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default And Speaking of Batteries and Center of Gravity

What's a kilogram?Â* I use pounds.

On 11/16/2018 10:37 AM, Pat wrote:
Don't forget to take into account the new definition of a kilogram.


--
Dan, 5J
  #10  
Old November 16th 18, 05:57 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 465
Default And Speaking of Batteries and Center of Gravity

On Friday, November 16, 2018 at 12:24:20 PM UTC-5, Dan Marotta wrote:
I'm thinking of eliminating the tail battery in my Stemme but need the
weight for proper balance.Â* I know I could replace it with pure lead,
but that's a lot of work so I've come up with a plan that would be more
satisfying and I would like comments and/or suggestions.

My thought is to discharge the battery fully.Â* It's a standard AGM that
everyone uses.Â* Then drill a couple of holes in the case and flush out
the electrolyte a couple of times with water.Â* Then fill the case up
with a highly saturated solution of NaHCO3, baking soda if I have the
formula correctly, and completely neutralize any remaining acid.Â* A
final flush with pure water, let it dry out, and finally, I could add
just about anything inert to bump the weight back up to what it was, and
plug the holes.Â* Voila!Â* A perfectly sized ballast weight.

Comments?Â* Have I missed anything?
--
Dan, 5J


Unlike a "wet cell" battery, the electrolyte in the AGM (SLA) is semi-solid (gel in mat) and flushing it out would be difficult.

Why not simply leave the battery as-is? You can disconnect it from the electrical system but there is no need to flush it. Just inspect it every few months to check whether it is cracking up or anything. And replace with another old battery after a few years. I havn't had such a battery leak yet, including some that are 20+ years old (they're not in my glider!).

One caveat: the electrolyte can freeze at low enough temperatures. To avoid that, the battery should be fully charged. Even if it's an old battery with reduced capacity you can still charge it as much as it will take. Such batteries can hold the charge for a year or more.
 




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