Replacing an SRM battery... at home :o)

Discuss light weight issues concerning road bikes & parts.
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mzagorski
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by mzagorski

The battery in my Dura-Ace SRM died so I decided to repair it myself. Took some photos during the process if anyone is interested:

http://www.mikezagorski.com/archives/000700.php

Here are some photos...
Attachments
2006-12-7_srm20.jpg
Done!
2006-12-7_srm18.jpg
Phew!
2006-12-7_srm17.jpg
Soldering in the new battery.
2006-12-7_srm9.jpg
The old dead battery. Electrochem Lithium QTC85 3B880
2006-12-7_srm6.jpg
Inside the SRM.
2006-12-7_srm4.jpg
Removing the white disc / cover after chainring removal.
Last edited by mzagorski on Sat Dec 09, 2006 2:06 am, edited 2 times in total.

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LJ
WWotY 2006 / Smart convert
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by LJ

Very interested, thanks.

They dont advise you do this yourself so thats a big pat on the back from me! :shock:

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Boonen
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by Boonen

Nice job, thanks for taking the pictures :thumbUp: Those might come in handy one day :D

Kuiper
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by Kuiper

Very interresting post Mike,
Have never seen a SRM - inside 8)
you did it but does it also work? :P

mzagorski
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by mzagorski

The problem was that i felt like I was going at 500w when SRM was reading maybe 200w.. lol... checked the zero offset.. and it would start at 420 or so and just decline to very low numbers.... meaning battery was dieing. Tired of sending stuff back to SRM for $$$ repairs so after some advice from people decided to take a chance and do it myself. Wasn't that hard.. Just gotta take your time, be careful with the soldering etc.

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mike18
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by mike18

Do u know what it costs to let the battery change by SRM?

cambo
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by cambo

how old are is your system, I just bought some and wondering how long it will be till they need new batteries? of course it will depend on how much i use it though.

mzagorski
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by mzagorski

New battery is probably something like $50.. but then there's the cost to ship the SRM to Colorado (if you're in the US)... and for them to repair it and send it back... Time and Money... I don't have a second crankset to use if I sent the SRM back. I've had bad experiences with customer service at SRM this year in the US.... maybe SRM is just becoming too popular and sometimes they're very very busy. LJ said they advise not to do that yourself... Sure... As well as the risk of you breaking it... they'd also lose out on making money if people repaired SRM's at home. I just spent $100 or so for a piece of plastic cover on my Powercontrol... overpriced IMHO.

I can't remember how long the batt is meant to last.. maybe 1-2 years or so. I put about 30,000km on my before it went dead.

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mike18
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by mike18

And the risk to do anything wrong is not so high and its working well like changed by SRM!

Cause next year I'll get a FSA version, but hav to change the battery, and I have to ship it to germany and back again!

So there is nothing to fear???

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LJ
WWotY 2006 / Smart convert
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by LJ

Personally, if you can turn your hand to it, then why not! Good job Mike.

cees
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by cees

mzagorski wrote:New battery is probably something like .



5 euro
skype Ceesbeers191053
www.ada.prorider.org

mzagorski
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by mzagorski

battery direct from electrochem in NY is $10. Shipping the battery to hawaii was the killer.. $30 for fed-ex. dangerous goods (lithium).

i just dont like the "oh.. it's super special and we are the only people that can fix it mentality"... we're all human.. all have arms, eyes, etc... not rocket science to change a battery. But if anyone does it and it goes wrong.. I'm not responsible :wink: definitely done at your own risk LOL.

Skillgannon
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by Skillgannon

Nice job mike, I was wondering if you were going to put up some photo's or not, as it's something that isnt done often and would probably be pretty handy to do. Is it possibly to change the powercontrol batteries as well (actually, would you ever need to change the powercontrol batteries?)

How much time did it take you to fit the new battery?

And seeing the inside, I've got a nasty feeling someone is eventually going to try WW tuning the inside of the srm to drop its weight closer to the DA crank :?

mzagorski
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by mzagorski

Time to replace the battery wasn't much. I probably did the whole process within an hour... well, 1.5hrs if I include the walk to walmart to get a soldering iron. Time to take off cranks, clean the srm, pry off the white disc, remove old battery by heating up existing solder... bend pins on new battery, solder the new one it... re-install everything, chainrings, and put back on bike. 1-1.5hrs total is enough I think. I didn't rush either.

powercontrol.. from what I was told the battery is glued into the case... the bottom piece I think. I've had two powercontrol batteries changed.. they die more often than the cranksets battery I think. I got the top piece of my PCV sent back to me... so could disect that sometime.

the inside also looks quite drilled out already. I doubt you can trim that much weight off really.

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pritchet74
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by pritchet74

Sweet! :thumbup:

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