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

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Bikey
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by Bikey

It is a custom battery.

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MiSzA (PL)
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by MiSzA (PL)

Yeap - it seems to have 3 modules - but still - there should be available replacements out there (given you can squeeze them into PC), right?

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Bikey
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by Bikey

3x1.2v button cells, ideally 100mah, need NiMH cells or LiOn. Need to have someone solder together the battery pack.

whodesigns
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by whodesigns

ElDuderino wrote:do you need to re-calibrate the SRM after changing the battery?


I recommend a calibration check after a battery change or annually.

There is a procedure in the manual or you can get a specialist to do it if you aren't confident to do it yourself.
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2 wheels
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by 2 wheels

spaniardclimber wrote:Anyone knows where to get this battery in Europe?

Online shop in England: http://www.smallbattery.company.org.uk/sbc_3B880.htm

gregalfa
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by gregalfa

gotta go it by myself soon. :D
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coloclimber
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by coloclimber

There are two rectangular shaped batteries in the SRAM SRM wired.
3.5v 750 mAH
LTC-7PN-S4
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-Deacon Doctor Colorado Slim

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spaniardclimber
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by spaniardclimber

I can't source the ltc-7pn-s4 in Europe...anybody knows where to find them here?

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by 2 wheels

spaniardclimber wrote:I can't source the ltc-7pn-s4 in Europe...anybody knows where to find them here?

It can be very hard to find this for sale online in Europe I think.

But I found out you can buy a Gemini SER-9512 Service Kit for Gemini Tinytag Transit (TG-0050) Temperature Logger:
http://www.geminidataloggers.com/access ... s/ser-9512
The SER-9512 Service Kit is just a Keeper II LTC-7PN-S4 battery with a service instruction sheet for the TG-0050 temp. logger.

Image

Here's an UK shop selling the SER-9512 Service Kit for 9.95£ http://www.alanaecology.com/acatalog/Ti ... e_Kit.html
Not sure about oversea shipping rates. It can be expensive because some batteries are not allowed to be shipped with regular air mail.

Another UK reseller: http://www.omniinstruments.co.uk/produc ... .id22.html
But they charge 50£ to ship to mainland Europe.

A German reseller: http://www.bmc.de/product.php?artnr=SER ... nd-wartung

And an US reseller selling the kit for 14$ http://www.micronmeters.com/store/prod- ... 0_-83.aspx
This is cheaper than the battery alone at some other US resellers.

You can find all Gemini distributors here: http://www.geminidataloggers.com/distributors

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coloclimber
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by coloclimber

2 wheels. Thanks, that "kit" is much cheaper than the battery itself.
-Deacon Doctor Colorado Slim

mrfish
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by mrfish

Once you start messing, you may as well go the whole hog and start changing things. Inside the hard metal case of the supplied battery I'd bet you would find a standard LiPo cell, which suggests the supplied battery may be rechargeable using an appropriate LiPo charger program.

Since electonics can't tell what battery you're using you could replace the manufacturer's battery with any other that has the same voltage, cell chemistry and similar capacity.

I'd recommend using a single cell lithium polymer 750mah cell as supplied in model shops for use in small electric helicopters. Availability is pretty much global and cost is about £5. These are definitely rechargeable (with appropriate charger) and will require some silicone sealant or double sided foam tape to fix. Also since this is weightweenies they will be lighter since they use heatshrink for protection rather than a hard case.

.

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spaniardclimber
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by spaniardclimber

mrfish wrote:Once you start messing, you may as well go the whole hog and start changing things. Inside the hard metal case of the supplied battery I'd bet you would find a standard LiPo cell, which suggests the supplied battery may be rechargeable using an appropriate LiPo charger program.

Since electonics can't tell what battery you're using you could replace the manufacturer's battery with any other that has the same voltage, cell chemistry and similar capacity.

I'd recommend using a single cell lithium polymer 750mah cell as supplied in model shops for use in small electric helicopters. Availability is pretty much global and cost is about £5. These are definitely rechargeable (with appropriate charger) and will require some silicone sealant or double sided foam tape to fix. Also since this is weightweenies they will be lighter since they use heatshrink for protection rather than a hard case.

.

The problem with lipos is that if they loose charge completely they're dead. At least this is what I've understood. A good idea would be to recharge them every year.
Can any lipo expert tell us if this would be a good idea?
Lipo chargers are expensive too, cheaper than sending the crank to srm though...
Who wants to be the first to experiment?

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by 2 wheels

mrfish wrote:Once you start messing, you may as well go the whole hog and start changing things. Inside the hard metal case of the supplied battery I'd bet you would find a standard LiPo cell, which suggests the supplied battery may be rechargeable using an appropriate LiPo charger program.

Since electonics can't tell what battery you're using you could replace the manufacturer's battery with any other that has the same voltage, cell chemistry and similar capacity.

I'd recommend using a single cell lithium polymer 750mah cell as supplied in model shops for use in small electric helicopters. Availability is pretty much global and cost is about £5. These are definitely rechargeable (with appropriate charger) and will require some silicone sealant or double sided foam tape to fix. Also since this is weightweenies they will be lighter since they use heatshrink for protection rather than a hard case.

.

No, you are wrong, LTC-7PN-S4 is not a LiPo or even a rechargable battery.
EaglePicher Keeper II LTC-7PN-S4 datasheet: http://www.epcompower.com/images/stories/ltc7pn-1.pdf
LiPo would be a bad choice for this application as it has a higher self discharge rate and therefore wouldn't last as long when left unused. And without a charge plug, using a recrageble battery make even less sense as the energy desnsity is less and the battery probably expensive.
The battery is a Lithium Thionyl Chloride (Li-SOCl2) primary cell (primary cell = non-rechargable and secondary cell = rechargable).
The good thing about Lithium Thionyl Chloride (Li-SOCl2) batteries is the very low self discharge rate (< 1% per year). This means they will last for many years if not used.

Do not try to charge these non-rechargable batteries. You might start an explosion or fire by doing so.

And you should also be very careful charging LiPo / Li-ion battery cell. It's very critical how they are charged and temperatures etc. should be monitored while charging. There's a reason why end customers can't buy bare LiPo / Li-ion cells, since it's dangerous to charge these. The LiPo / Li-ion batteries you buy for cell phones, laptops etc. has built in charging protection circuit to avoid fires or explosions. It think most people have heard of all the recalled defect SONY laptop Li-ion batteries. These were recalled because some exploede or caught fire.
Do not even try to charge any bare LiPo / Li-ion cells unless you are absolutely sure what you are doing and know a lot about electronics. A lot of people have exploded LiPo / Li-ion cells trying to charge their own bare cells for RC models etc.
And if Li-ion / LiPo cells have been discharged too much, you can't just recharge them again, which is why power cuts off in e.g. a laptop or cell phone before the charge voltage drops so low that the cells can't be charged again.

Bare NiMH and NiCd cells on the other hand are sold to end customers and there's very little risk charging those as opposed to LiPo / Li-ion. Charging and using LiPo / Li-ion is much more complicated than charging NiMH and NiCd.


http://www.epcompower.com/content/view/53/7
Non-Rechargeable Chemistries

LiSOCl2 (Lithium Thionyl Chloride)
As the first and still the only producer of a prismatic LiSOCl2 cell, EaglePicher is truly an innovator in this chemistry. LiSOCl2 cells and batteries have been in production at EaglePicher for over 15 years. Our line has expanded of to include cylindrical cells from a ½ AA up to D sizes as well as wafer designs, which means our LiSOCl2 line of cells can now handle any application you can dream of. The applications this chemistry powers enjoy the high energy density offered by a 3.6- volt chemistry that can be packaged in a small area. Add the 15+ years of confirmed shelf life, a flat discharge curve and wide operating temperature range (-55C to +85C) and it’s hard to pass up EaglePicher cells when designing a new product or replacing an old.

Auk
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by Auk

A bit of a revisit to the subject.

Recently I replaced the batteries in my Dura Ace crankset. Of course, I ordered the battary before I popped the back case off the crank. Not good. Turns out that mine takes the dual rectangle version rather than the single round battery. Total cost of the dual setup was $42.

A few days ago, I popped the back of the Powercontrol. Be mindful that one of the four screws are longer than the rest. Put it back where it came from. Took the battery pack down to the local battery store (Batteries Plus) and had them recreate the setup. Total cost $10.50 out the door.

If you can handle a soldering iron these are very easy projects to do yourself in under an hour, including clean up and sampling your favorite beverage.

by Weenie


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ms6073
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by ms6073

Auk,

Thanks for that update as I may be needing to replace the battery in my PCVI. I notice on the back of my PCVI, a couple of the screw heads have a glob of glue or similar, is this used to indicate non-SRM maintenance? Even though it is less than 1 year old, I have noticed that with all the time I have spent on the trainer over the past month, the times I have gotten outside, the PCVI seems to have lost most of the charge and this after only a week of non-use.
- Michael
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