Batteries

[Seth]

I'm about to purchase new batteries for my Mooney Missile. It takes two, not one, as it helps keep the weight aft. Plus it helps with starting power.

I purchased two concords, I think RG35A's in the summer of 2012, so I have 8+ years on these batteries, and they've sat during the last year (again, long write up coming).

They were on a trickle charger. But I figure it's time to swap them out.

 

Does anyone know of any black friday specials on concord batteries? I've already asked aircraft spruce and they are looking into it. I also contacted Concorde direct.

 

-Seth

[jaylw314]

No, but I'd suggest doing a capacity test on them before spending the $700.  There's at least a small chance they're still holding sufficient charge, IIRC the limit is 80% the original rated capacity.

 

I am curious about the Missile electrical system.  I assume it's still 12V?  Are the batteries wired in parallel or is there some kind of E-bus backup circuit?

Edited November 5, 2020 by jaylw314

[Missile=Awesome]

On 11/5/2020 at 4:44 PM, jaylw314 said:

No, but I'd suggest doing a capacity test on them before spending the $700.  There's at least a small chance they're still holding sufficient charge, IIRC the limit is 80% the original rated capacity.

 

I am curious about the Missile electrical system.  I assume it's still 12V?  Are the batteries wired in parallel or is there some kind of E-bus backup circuit?

They are wired in parallel.  They sit on a shelf in a box in the tail.  I had to make a special “slider” board as my plane didn’t come with one.  Without the board extracting the batteries is impossible for mere mortals without damage to the tail.

Important to ensure the two retaining fasteners are tight at least at annual as a shift of these in flight would be catastrophic...

[jaylw314]

46 minutes ago, Missile=Awesome said:

They are wired in parallel.  They sit on a shelf in a box in the tail.  I had to make a special “slider” board as my plane didn’t come with one.  Without the board extracting the batteries is impossible for mere mortals without damage to the tail.

Important to ensure the two retaining fasteners are tight at least at annual as a shift of these in flight would be catastrophic...

Is the second one just for the weight or does the starter actually require more juice than the normal io-360?

[Missile=Awesome]

1 hour ago, jaylw314 said:

Is the second one just for the weight or does the starter actually require more juice than the normal io-360?

Primarily weight offset of IO550, but bonus juice is nice.

[Tim Jodice]

7 hours ago, Missile=Awesome said:

Primarily weight offset of IO550, but bonus juice is nice.

Why doesn't the factory do this for the long body? Charlie weights are useless except for there weight. Why not a battery that is also heavy but offers more cranking/reserve power?

[Missile=Awesome]

45 minutes ago, Tim Jodice said:

Why doesn't the factory do this for the long body? Charlie weights are useless except for there weight. Why not a battery that is also heavy but offers more cranking/reserve power?

Dunno.  Mid body vs. long body weight needs?

[Davidv]

46 minutes ago, Tim Jodice said:

Why doesn't the factory do this for the long body? Charlie weights are useless except for there weight. Why not a battery that is also heavy but offers more cranking/reserve power?

They do.

[carusoam]

Find the XC batteries...

To some it means extra capacity...

To LBers it means extra weight...

Sure, its extra lead in the XC battery, but is more useful lead if you get a hot start problem...

Take a look at the Concorde site to see weights of the normal battery vs the XC...  a few pounds and a few amp-hrs...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Tim Jodice]

12 hours ago, Davidv said:

They do.

If they do why are charlie weights used?

[carusoam]

Designing in Charlie weights allows for flexibility for having options...

When loading the tail with options... the lead ballast gets tossed overboard...

The typical options for the long body include...

• Built in O₂ system
• AC
• FIKI

Not everybody is going to want these options... but having them, produces a really nice traveling machine...

Also standard back there is a secondary vac source... an electric pump. This device is getting to its logical end and is starting to get removed from some planes...

One day, there will probably be an O2 generator mounted back there....

PP thoughts only, not a plane sales guy...

Best regards,

-a-

[Davidv]

6 minutes ago, Tim Jodice said:

If they do why are charlie weights used?

Tim, my comment was that they all have 2 batteries.  Whether they have charlie weights or not I believe is to correct a CG imbalance (from a specific equipment configuration) that batteries could not do alone.  I don't think anyone would want to put in a third battery (expensive ballast without much more utility)!

Edited November 13, 2020 by Davidv

[carusoam]

The Rocket got a pair of batteries added specific for a WnB challenge that occurred after the M20K was originally designed...

They are a challenge to access because they are so far back...

 

The Long Bodies came later...

The battery access is doubly improved...

There are two access panels one on each side of the plane...

The dual battery design is a great improvement to electrical safety... similar to having a spare alternator, and an emergency bus...

If using your plane as a work machine... these things are greatly appreciated...

At the same time, with the two batteries, the UL is over 1k#s for the O... 1.1k#s for the Eagle...

The design flexibility has been good for over 30years... if you want to call it an imbalance, I’m OK with that... 

More PP thoughts...

Best regards,

-a-