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

Discuss light weight issues concerning road bikes & parts.
notaero
Posts: 26
Joined: Sat Mar 10, 2012 1:00 pm

by notaero

Rotor 3d+ SRM is indeed similar to any modern wireless SRM with 2x LTC7PN batteries.
Last edited by notaero on Fri Feb 08, 2013 9:33 am, edited 1 time in total.

by Weenie


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ms6073
Posts: 2301
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

notaero wrote:Rotor 3d+ SRM is indeed similar to any modern wireless SRM with 2x LTC7PN batteries.
So does your significant other know that you are using their cutting board to perform maintenance on your SRM? :mrgreen:
Michael - The Anaerobic Threshold is neither...

doggatas
Posts: 11
Joined: Sun Jan 08, 2012 7:49 am

by doggatas

WeightySteve wrote:The only thing keeping the cover on once the rings are removed is friction between the internal rubber seal and the spider housing
however, there is enough friction involved so as not to let the cover "pop off" when you remove the rings. Don't worry, changing the rings is just as trivial as changing them on a normal (non SRM) spider.


Thanks Steve.

tetonrider
Posts: 92
Joined: Wed Oct 06, 2010 3:38 am

by tetonrider

devinci wrote:
DartanianX wrote:Does anyone know how to use the new software function to check the levels of the battery crank?


I was told its when you dld a training file from the PC7, I guess its via the SRMwin software, but not sure. This is an awesome feature though.


^^ this is it. you must use SRMwin -- this does not work in SRMmac.

not sure if your SRM's firmware had to be updated to make use of this. i know i had a unit that was a newer one (1700h battery life) that displayed the older capacity. i was told it was due to a firmware issue.

pcates
Posts: 11
Joined: Tue Feb 12, 2013 6:57 pm

by pcates

Is anyone familiar if there is another type of battery which can be used instead of the Keeper LTC-7PN-S4? I'm having a hell of a time finding one in Canada and the ones i find in the US won't ship to Canada.

Or does anyone know of a Canadian source?

Thanks

sungod
Posts: 1418
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

check locally for equivalents under different part numbers like er651625

also try variations with different pin configurations - both bent (s2) and straight-pin (s4) versions are fine, the four-pin version can be used simply by 'peeling' the extra cathode pins away from the case

otherwise, i believe sbc will ship to canada (their 'worldcart' lists it as an option)...

http://www.smallbattery.company.org.uk/

http://www.smallbattery.company.org.uk/ ... ldcart.htm

pcates
Posts: 11
Joined: Tue Feb 12, 2013 6:57 pm

by pcates

Thank you sungod! i think i was being a bit too specific in my search....this makes things much easier.

btw. If anyone in Canada is looking for a replacement battery there is a brand called MadgeTech LTC-7PN. They use them in data loggers, and that sort of thing.

itimation
Posts: 1
Joined: Thu Mar 07, 2013 8:58 pm

by itimation

Hi, can anyone tell me if this battery suits for the PC V ?!

http://www.reichelt.de/Memopuffer/3GP-6 ... tnr=3GP-60

thnx :)

willsim
Posts: 1
Joined: Fri Jun 14, 2013 1:08 am

by willsim

Hi everyone , this is my first post but need your help!

i currently am running a wired dura-ace 7800 srm with PCV head unit. now...of course..two weeks from
nationals it decided it was going to run out of battery power and is currently a very expensive heartrate
speed and time computer. so in the quest to get back into a working state i decided to go down the route
of replacing the batteries myself :unbelievable: well i opended it up this evening and found 2 square yellow batteries
made by keeper ( 3.5v 750 mAH LTC-7PN-S4 ) < thats the battery code i belive.

so so far seems pretty easy came apart easy enough (one stripped chainring bolt ) ,
lets just order two new ones! well not that simple... theres place in my city that carrys
all kinds of batteries and they do have this batterie....i belive? well this where i need your help.
the ones they have are identical ( same company and demensions) but they are 3.6v instead of 3.5v . would this be a big diffrence? or any diffrence?.
if so i need to order some new ones asap ( if you know a link ..that would be epic :thumbup: )

any one with some adive that would be great! help me please i need this done as soon as possiable as i leave
in a week and half!

thanks all!

will

(im from canada keep in mind)
heres a link to what the battery looks like

http://www.bing.com/images/search?q=srm ... tedIndex=0

http://www.bing.com/images/search?q=srm ... tedIndex=1

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ms6073
Posts: 2301
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

I had to replace batteries in a wireless SRM some months back and got the 3.6v 750mAH battery except with 4-leads and have had no issues. I will warn that the wires that you solder from SRM to the battery are very small diameter (30 gauge?) and may have gotten fragile with age so best to have suitable replacements on hand in case - I did not plan ahead and ended up sacrificing a generic PC cooling fan last time I replaced batteries.
Last edited by ms6073 on Thu Aug 10, 2017 7:57 pm, edited 1 time in total.
Michael - The Anaerobic Threshold is neither...

sungod
Posts: 1418
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

willsim wrote:<...>
the ones they have are identical ( same company and demensions) but they are 3.6v instead of 3.5v . would this be a big diffrence? or any diffrence?
<...>


the difference, 3.5 or 3.6, is just due to differences in the specified load at which the rated voltage is obtained, at the same load the batteries would give the same voltage, they're interchangeable

see my earlier post for hints on widening the search for compatible batteries...

viewtopic.php?f=3&t=24359&start=150#p960484

wetpaint
Posts: 82
Joined: Sat Feb 06, 2010 2:55 am
Location: USA

by wetpaint

ms6073 wrote:I had to replace batteries in a wireless SRM some months back and got the 3.6v 750mAH battery except with 4-leads and have had no issues. I will warn that the wires that you solder from SRM to the battery are very small diameter (22-gauge?) and may have gotten fragile with age so best to have suitable replacements on hand in case - I did not plan ahead and ended up sacrificing a generic PC cooling fan last time I replaced batteries.


Same thing happened to me on my last battery change, had to resolder wires to the board

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si1ver
Shop Owner
Posts: 309
Joined: Tue Jan 10, 2006 3:53 am
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by si1ver

I am sorry if this has been answered before but is calibration necessary after replacing the battery ?

sungod
Posts: 1418
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

calibrating every so often is best for consistent/accurate results, if an srm hasn't been calibrated since new/last battery change then it could be a few % out

by Weenie


antani
Posts: 1
Joined: Sat Jan 18, 2014 2:14 am

by antani

this is my first speech on the forum
greetings to all

have found increased durability with EVE EF651625-S4 or with the classic Eagle Picher Keeper LTC-7PN-S4

Which do you prefer?

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