Holder for 14250 batteries in ICAS smoke detector

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This Norwegian ICAS smoke detector originally came with a soldered-in 10-year lithium battery consisting of three primary cells that each supplied 3.6 volts. The battery was radioactive in nature, which means it would gradually become less sensitive to smoke over time; however, they no longer manufacture these types of batteries, so I now use this one as an additional smoke detector alongside an optical one. Each type has its advantages and disadvantages, making it beneficial to have both. After nine years, the battery's power began to wane, leading me to consider replacing the primary cells with lithium-ion ones that could be recharged periodically. We regularly test our smoke detectors once or twice a year. To see how this modification works out, I designed a battery holder for three half-AA size cells like these https://www.aliexpress.com/item/Free-shipping-10Pcs-1-2AA-Battery-CR14250-14250-CR-3-7v-300mAh-Lithium-Battery/32817308573.html?spm=a2g0s.9042311.0.0.70524c4daMCZSs. It's also possible to purchase individual battery holders like these https://www.aliexpress.com/item/10pcs-Black-Plastic-Battery-Box-Container-Storage-3V-Batteries-Holder-Case-Wire-Leads-For-14250-Battery/32823590146.html?spm=a2g0s.9042311.0.0.70524c4daMCZSs, but there isn't enough space inside my smoke detector for three of those, so I removed the contact spring from one and reused it in this design. If I were to do it again, I would use the inexpensive spring plate contacts like these https://www.aliexpress.com/item/100pcs-Battery-Battery-shrapnel-AA-or-AAA-battery-spring-5-No-positive-and-negative-contact-pieces/32881285245.html?spm=a2g0s.9042311.0.0.70524c4daMCZSs, but this design still works for my purpose. For the end of the battery that makes contact with the board, I wrapped two turns of solid copper wire through the small holes and bent them down before soldering them to the board. I was able to use the original solder points on both ends, which fits perfectly. The modified design consisted of taking thing:2616101 by stylesuxx, making the ends slightly thicker, and adding cutouts for the spring contact and the wrapped-wire contact at the other end.