Battery for Siemens TEK/Rexton BLU RCU remote

Anyone know where to find an aftermarket battery for a Siemens TEK/Rexton BLU RCU remote? I’d like to keep a charged spare on hand, but I cannot find a part number on the original battery. It’s marked “Siemens Li-Ion Battery Rated 3.7V 1000mAh3.7Wh” (plus all the usual warnings, a manufacture date, and a serial number).

I’m guessing it could be the same as some common cell-phone battery.

http://precisehearing.com/hearing-aid-accessories/bluetooth-devices

That size battery seems to also be used by Ipod and LG phones. What kind of connector is it, a wire like this or built into the battery?

http://www.radioshack.com/product/index.jsp?productId=2596085

The battery has three contact pins set into the lower left end – looking down on it when it is installed. No dangling wired connector.

Perhaps if I take it to BatteriesPlus, they will recognize it – although I am sure I will not like their price.

Batteries Plus can’t find a replacement, and the guy there said the contacts are different from those typically used in cell phones.

my Tek that came with my Rextons over 3 years ago will still hold a charge all day on standby without any problem. If I’m streaming TV I just plug it in and lay it on the arm of the chair. Have you tried Costco? if I’m in the car all day I just it into one of the lighter outlets.

car charger
http://www.thehearingcompany.com/Car-Charger-for-Siemens-TEK-or-miniTek-remote_p_230.html#

battery
http://www.thehearingcompany.com/Rechargeable-Battery-for-the-original-TEK-Remote-Control-not-for-minitek-picture-shown-not-accurate_p_231.html

It’s been a long time, but I did get round to asking at Costco: battery has to be ordered and costs $22.99 – much cheaper than the $50 I found on line. Still haven’t decided whether to buy one.

Did you ever order one from COSTCO?
If so, is there a part number or other ID.
I have tried at a Costco without success.