Replacing The Coin Battery In the Specialized SL TCU Gen 1

[etgo]

any one having problem after chaging the tcu batt? (tcu gen 1)
before, once i press 1x my tcu turned on right away.
after replacing the tcu batt, i need to press 3x to turn on the tcu.

 

[Saratoga Dave]

Holy smokes, what a party that was! Finally got it with Art’s technique of the jeweler’s screwdriver all by itself, but it was my wife who finally made it happen. What a jackass excuse for a design, though!

As for etgo’s note above, it has almost always taken me two presses of the start button to get the TCU turned on, and now after the replacement, the same thing is true. Mind of it’s own.

 

[neighbor-ryan]

My wife got it, using just small bathroom scissors: depress the tab and work the battery out, from the tab side. Very relieved to not have to take it in.

We tried to "simultaneously hold flap open, depress tab with tweezers, and lever battery out with scissor" for a while, but gave up. Then she figured it out with just the scissors.

 

[matt-h]

Thanks everyone! I used the procedure you described (particularly Stefan) to replace the battery in my wife's TCU. One thing I did differently is that, rather than using a needle as Stefan suggested, I used the tool pictured (which I happened to have in my toolbox). I think it has a bit more leverage than a needle. If I do it again, I might try to wrap it with a thin layer of something to give it a bit more friction.

 

[BioWheel]

Thanks everyone! I used the procedure you described (particularly Stefan) to replace the battery in my wife's TCU. One thing I did differently is that, rather than using a needle as Stefan suggested, I used the tool pictured (which I happened to have in my toolbox). I think it has a bit more leverage than a needle. If I do it again, I might try to wrap it with a thin layer of something to give it a bit more friction.

View attachment 183351

Guy posted on FB recently he just hits the TCU into his palm and battery comes out - no tool needed.

 

[Phil Howell]

I tried plastic tweezers (the little needle-shaped tips broke off in the unit). Next, I tried a small metal pick, but that didn't work. I tried the hitting on my hand to get the battery to fall out method. That didn't work for me, either. I finally stuck a small zip tie down the side of the battery and pulled the zip tie out while depressing the clip. The battery came out far enough to get it with needle-nose pliers. What a stupid, stupid design!

I just ordered plastic tweezers with flat jaws from Amazon that may work the next time I need to replace the battery.

 

[Allan47.7339]

I have found the easiest method is to use either a small flat screwdriver (0.1in or 3mm blade) or a scalpel hobby knife (x-acto) to carefully flex the retainer lip down and let the battery slide out. May need to use the tip of the knife to help it slide out.

 

[Tarcher]

Guy posted on FB recently he just hits the TCU into his palm and battery comes out - no tool needed.

Easiest way I found that doesn’t risk damage to the tcu is to unplug the 2 connector wires from the tcu, remove unit from bike, depress retaining tab and lightly tap tcu housing on a hard surface and the battery just falls out. Once battery is replaced (note which side was up before removal), close rubber door, reconnect wires by carefully matching tabs on connectors and reinstall tcu.

 

[Allan47.7339]

Easiest way I found that doesn’t risk damage to the tcu is to unplug the 2 connector wires from the tcu, remove unit from bike, depress retaining tab and lightly tap tcu housing on a hard surface and the battery just falls out. Once battery is replaced (note which side was up before removal), close rubber door, reconnect wires by carefully matching tabs on connectors and reinstall tcu.

The was a post on the FB Creo site to use a magnet to pull the battery out while depressing the retainer. I may try that next time.

 

[charleyt]

Whenever you get this error message on your SL TCU Gen 1:
View attachment 150785
(The blue and red bars far apart, the red LED flashing) then you need to replace the CR1620 coin battery. Which is not the easiest task.

Prepare:

• A fresh CR1620 battery
• The T10 Torx key
• Tweezers
• A thin, long and sharp object such as small scissors.

Replacing the battery in the TCU is as troublesome as it is with some wrist-watches: limited space makes the removal of the original coin battery difficult.

Remove the screw from the TCU and pull the unit outside. If you want to remove the unit completely, you need to pull it forward (in the direction of the handlebars).
View attachment 150786
The internals of the TCU are protected against the moisture and dust with a rubber flap marked with the USB icon, open the flap. You will see the service micro-USB socket and the battery in a very narrow slot.


View attachment 150787
There's a tiny shiny piece of elastic metal to keep the battery in place. Using tweezers and your non-dominant hand, keep the piece of metal depressed. Use your dominant hand and the long sharp thin object to drag the old battery out (it is the infuriating part of the task there!). Replace the new battery as shown. Close the flap. Secure the unit in the frame with the screw.

The procedure can be pretty irritating. Thank you @kahn for heads-up of several months ago! Thank you @Allan47.7339 for explaining the error codes to me!

P.S. The original battery was good for 359 rides in 21 months. I found the rubber flap opened and expect there could be some water ingress into the unit to produce the error code. I dried the inside of the unit with compressed air before inserting the fresh battery.

Hi. Is this battery replacement still necessary with the CREO 2? I received a message on my Garmin stating 'ebike sensor critical low.' I went into my Garmin and turned off ebike sensor. But now I'm wondering if there's a battery on the TCU that needs to be changed. Thanks.
Update: for the CREO 2, there is now a USB-C port that you can charge. There is no indicator that the battery is low. There is no indicator that the TCU is charging. LBS says they to just plug it in once a year and should be okay. So if it wasn't for my Garmin stating 'ebike sensor battery low' I'd have no clue. This doesn't make a lot of sense to me and was never told I needed to keep the TCU battery charged annually. What is the worst case? Battery on TCU dies and then the bike dies?

 

[Stefan Mikes]

The Difference Between The Gen 1 TCU and Mastermind TCU

• With the Gen 1 TCU, you need to replace the coin battery inside the unit when the red and blue LEDs are flashing as shown in Post #1.
• With the Mastermind TCU you should recharge the unit's internal battery by USB-C once a year.

 

[Allan47.7339]

The support site has been updated with a lot of information that was previously only on the dealer portal. I am not aware of the Mastermind needing a charge unless it's not been used for a quite a while.

https://support.specialized.com/kb/sp_en-us/content/ECV3-5039/TCU-Replacing-the-Display-Coin-Cell

Function of Display Coin Cell

The CR 1620 coin cell in the display has these two functions:

Error events are saved with the correct date and time stamps
The bike can be powered on with a short TCU button-press, compared to a longer button press with an empty coin cell

Effect of Empty Coin Cell

The function of the Turbo bike as such will not be affected. These are the effects of an empty coin cell:

TCU will show corresponding message (see below)
Bike needs to be started with a longer button-press on the TCU
Error/event logs cannot be saved with correct date/time stamps any longer

When the date/time association is disabled due to an empty coin cell, you need to replace it with a new one and connect to the Specialized app so that the correct date and time is applied again.

 

[sanyata]

Serendipity!!! I started my Levo yesterday and had this error message for the first time ever. It's not described in the manual, so I was at somewhat of a loss. I sort of figured it might be the TCU battery but had no idea what was involved with its replacement. Thanks to all that posted in this thread!

 

[sanyata]

Update: I was able to get the battery out by pushing up the spring tab with a pick, which stayed up, and then tap the battery out by somewhat gently tapping the unit on the countertop with a towel to cushion the blows. It took several taps to get it halfway out and took maybe three minutes.

 

[afrancombe]

Having read this thread I approached the need to replace the battery on my turbo creo with some trepidation. First time since purchase in Nov 23 and 3-4 days commuting 24 miles per day. I squeezed the small metal clip out of the way with tweezers while inserting a tack (the type used in picture hangers) down the side of the battery wriggled it around and it came away fairly easily. job done.