Red Lion RRPM Battery Replacement

Penguin

Too Short a Member
Joined
Nov 21, 2009
Messages
1,613
Location
Satellite Beach, FL
Aircraft
Dominator, 582, 23' Dragon Wings, 60" Warp Drive
Total Flight Time
250+ hours
The Red Lion time-based counter is popular for measuring rotor revolutions per minute (RRPM). A robust, easy to read instrument, it has only two shortcomings: the battery isn't replaceable and the unit is expensive (about $80).

But nothing is too challenging for the gyronaut, so here is my step-by-step method to replace the battery. (The factory claims the battery is good for 7 years but mine died at 4.5 years. Hostile environment and all that, I suppose.)

You'll know that the battery is dead only because you no longer have a display. Not even the zero. Nothing. So time to buckle down and get to it.

After removing the display head and the wires connecting it to magical stuff, remove the back cover which unveils the switches and the battery. Unfortunately, the battery is not designed to be removed and replaced. But that won't deter us, will it?

The unit is composed of two halves: a display section and the electronics section. Carefully separate these pieces so you can have access to the circuit board (the obverse of the switch side). There are some 4 plastic clips that hold it that can be manipulated with a small flat screwdriver. You will, of course, break at least one. No matter.

The stock battery is spot welded to two metal supports which provide continuity between the battery and the circuit board and also the mechanical structure to hold the battery.

Looking at the circuit board, identify where the battery supports are soldered in place. Carefully heat these joints, removing the solder with a solder sucker (small rubber bulb creates a vacuum to suck the liquid solder up) or a wick.

Now that you have the battery in your hand, you'll note a couple of things. First, it is not a common battery size but is a 2/3AA battery. As the name implies, it is 2/3 the length of a standard AA battery. (One of you WILL try cutting down a battery. Please post pictures.) This is not a Walmart or Radio Shack item. If you don't have a battery specialty store close, you can order it off the internet for less than $10.

Another thing is that you'll see that the supports are spot welded onto the battery. Carefully remove these with a pair of needle nose pliers and a razor knife. (Apply antibiotics and band-aids where you just cut yourself.) They'll come off cleanly and you'll reuse these with the new battery. BTW, you can't get a new battery with the support welded in place. At least I couldn't find anything like that.

I attached the supports to the new battery using a glue gun. (The bigger the glob, the better the job!) Remembering when you removed the old battery, there is a lot of space available for a big old goober of glue. Use a volt meter to insure you maintained good contact between each support and the battery.

Now solder the new battery's supports back into the circuit board, noting polarity. (Aloe is good for those burned fingertips, BTW)

At this point you can snap the display back in place. (You did mark it before disassembly so it would go back in the same orientation, didn't you? Nahh, me either.)

Once the display is back in place, you should see a nice zero on your display. If not, disassemble and check for power from the battery to the board. If there is power and no display, your board must be dead. Sorry.

Looking into the back (battery compartment) of our now functioning display, you can see that there are ample opportunities to smear more hot glue around to strengthen the assembly. Fortunately, the glue is relatively easy to remove with a razor knife should the need arise in the future. Double check the switch settings before you pour on the glue, BTW.

Now reinstall the unit. At this time you will discover that the wires connecting the instrument to the sensor are about an inch too short for you to reattach without the digital agility of a gynecologist. I'll provide a separate note on wire stretching techniques at some future time.

So you now have the satisfaction of a repair well done and saved yourself $70 to boot. Please send me $5 and we'll call it even. What? You cheap bastard!
 

cesphil

Member
Joined
Jan 30, 2012
Messages
133
Location
Tampa
Aircraft
Cessna 150 and Dominator
Total Flight Time
960
battery

battery

Larry,
What is the voltage of the battery? Why not use a battery of similar voltage mounted remote to the unit. This could be less invasive and facilitate replacement the next time.
 

Penguin

Too Short a Member
Joined
Nov 21, 2009
Messages
1,613
Location
Satellite Beach, FL
Aircraft
Dominator, 582, 23' Dragon Wings, 60" Warp Drive
Total Flight Time
250+ hours
Well, let's see ... The Google says it is a 1.2V battery. CORRECTION - the battery is a 3V as discussed below.
No reason not to remotely mount another type of battery.
You could even mount the holder to the back cover of the Red Lion, I suppose.

Good suggestion.
You can keep your $5 ...
 
Last edited:

RICK MARTIN

Gold Member
Joined
Apr 20, 2004
Messages
2,162
Location
BRADENTON, FLORIDA
Aircraft
Everglades Kite Gyro, Tandem Dominator
Total Flight Time
900 hours
GOD.....................................I love this forum. You guys are great! The glue is a great idea. They have been known to vibrate loose.

Thanks again guys.
 

gyrojake

Gyro Rehab Candidate
Joined
Jan 1, 2007
Messages
2,308
Location
E-City, Florida
Aircraft
Gyroplanes
Total Flight Time
A few hours
All of the batteries I have ever changed in a Red Lion were 3V.
Push the detentes on the side in, take the bottom off, unsolder post(Use solder wick to remove)
and remember polarity for reinstallation.
I use the battery for a motion detector $7.
Or you could buy a 3v regulator and wire it to your electrical system. LM 7803 is the device number.The battery is a 123 pile lithium. Also known as a CR-17345
 
Last edited:

Penguin

Too Short a Member
Joined
Nov 21, 2009
Messages
1,613
Location
Satellite Beach, FL
Aircraft
Dominator, 582, 23' Dragon Wings, 60" Warp Drive
Total Flight Time
250+ hours
Jake is correct. (As usual. Don't you just hate that?)
The battery is a 3V. I should have gone to the data sheet rather than going to The Google. (Bush The Lesser reference)
His technique is the same as mine. But not as fun to read.

I was going to post pictures, but that didn't work out.
BTW, does anyone know how to get hot glue off a camera lens?
 

RayPierce

Gold Member
Joined
Oct 30, 2003
Messages
1,324
Location
Aiken, South Carolina
Aircraft
GyroBee
Total Flight Time
More than 20 less than a million.
BTW, does anyone know how to get hot glue off a camera lens?
Well if we are trying for humor a 6" Milwaukee side grinder should get it off.

Super glue - Acetone.
Hot melt - extreme cold makes it brittle and easy to break.
 

EI-GYRO

21st Century Crankhandler
Joined
Oct 31, 2003
Messages
2,273
Location
Dublin, Ireland
You can do similar with the TinyTach erpm/hobbs gauges.
You need to cut off the back and carefully tunnel through the rubbery filler to find the flat cell battery.

Very entertaining description in post #1. Loved it.
 

madwinger

OldFartium Member
Joined
Apr 10, 2013
Messages
713
Location
Bountiful, Utah
Aircraft
No longer own a gyro.
Total Flight Time
64 SEL in training, 0 Gyro

cesphil

Member
Joined
Jan 30, 2012
Messages
133
Location
Tampa
Aircraft
Cessna 150 and Dominator
Total Flight Time
960
How about using a CR123A battery with a remotely mounted holder so that the battery can be easily replaced in the future.

They are 3 volt lithium batteries that are available anywhere for next to nothing. They are used in many cameras.

The battery holders can be purchased on Ebay for about $2.
 

Attachments

  • s-l225RWL2BS5H.jpg
    s-l225RWL2BS5H.jpg
    5.9 KB · Views: 3
  • s-l400.jpg
    s-l400.jpg
    6.7 KB · Views: 2

madwinger

OldFartium Member
Joined
Apr 10, 2013
Messages
713
Location
Bountiful, Utah
Aircraft
No longer own a gyro.
Total Flight Time
64 SEL in training, 0 Gyro
How about using a CR123A battery with a remotely mounted holder so that the battery can be easily replaced in the future.

They are 3 volt lithium batteries that are available anywhere for next to nothing. They are used in many cameras.

The battery holders can be purchased on Ebay for about $2.

That's a good idea. the Battery case can be placed where you can get to it easily, then not halving to take out the gauge and dismantling it is a big plus. I like it.

The tabbed battery is already ordered as I have removed the Tach to sell. If I were to be keeping and flying, I would do this.
 

giro5

Senior Member
Joined
Mar 19, 2006
Messages
1,265
Location
Farmington, New Mexico
Aircraft
prev- citabria,AA1b, fun racer
Total Flight Time
400 GA, 50 trike
Got the case separated but have yet got the board and battery out of its case??? cannot see any tabs. going to unsolder a few places and see if it will come out then?? Have to order the solder wick.
 

giro5

Senior Member
Joined
Mar 19, 2006
Messages
1,265
Location
Farmington, New Mexico
Aircraft
prev- citabria,AA1b, fun racer
Total Flight Time
400 GA, 50 trike
Got the solder wick in and de soldered the unit. First pic shows front case that has the lcd lens. note 3 holes on each long side where there are tabs in each of these and instead of trying to push down the tabs just slip a thin blade under the case edge and lift the case edge over the tabs. to separate the front and back halves of the unit. Next look at the 3rd and 4th pics the black case has 2 small posts on the left end and one on the right these are soldered to the electronic pc board and must be de soldered to remove the board and attached battery. the battery is under the pc board so this assembly has to be removed to get at the battery. Picture 2 shows the battery removed from the pc board (note the dip pin switches if you are wondering how to set up the unit for use) The tabs are spot welded to the battery so you unsolder the tabs from the pc board. Google the battery number and you will find lots of places to order the new battery with tabs.
Now if I just haven't gotten anything too hot on the pc board maybe I can put it back together and it will work. If not a new unit will set me back $146. And next time I will go with plan B which is to mill the back of the pc board case off/out and remove the battery that way . Bought a 1/16 end mill to do just that but I was able to get things apart without doing that.
 

Attachments

  • 2022 red lion 2 003.JPG
    2022 red lion 2 003.JPG
    94.2 KB · Views: 4
  • 2022 red lion 2 001.JPG
    2022 red lion 2 001.JPG
    138.1 KB · Views: 4
  • 2022 red lion 005.JPG
    2022 red lion 005.JPG
    118.2 KB · Views: 4
  • 2022 red lion 004.JPG
    2022 red lion 004.JPG
    113.7 KB · Views: 4

giro5

Senior Member
Joined
Mar 19, 2006
Messages
1,265
Location
Farmington, New Mexico
Aircraft
prev- citabria,AA1b, fun racer
Total Flight Time
400 GA, 50 trike
Got the new battery in today. wonder if it was the smallest box Amazon has to ship thing in?
 

Attachments

  • 2022 6 Red Lion battery replace 001.JPG
    2022 6 Red Lion battery replace 001.JPG
    134.5 KB · Views: 3
  • 2022 6 Red Lion battery replace 002.JPG
    2022 6 Red Lion battery replace 002.JPG
    125.3 KB · Views: 3
  • 2022 6 Red Lion battery replace 003.JPG
    2022 6 Red Lion battery replace 003.JPG
    130.1 KB · Views: 3
Top