{"title":"379 SR521SW Watch Batteries","description":"\u003cp\u003eThe 379 battery, also known by its IEC code SR521SW, is a 1.55V silver oxide button cell measuring about 5.8mm across and 2.1mm thick. Here you will find every 379 watch battery we stock, from Renata, Maxell, Seiko, Murata and Seizaiken, so you can pick the brand you prefer.\u003c\/p\u003e\u003cp\u003eThe easiest way to check you have the right battery is to read the number printed on the old one, then match it to 379 or SR521SW. Silver oxide cells hold a steady voltage for most of their life, which is why watchmakers prefer them for quartz watches.\u003c\/p\u003e\u003cp\u003eUK delivery is free on every order, and orders placed before 2pm Monday to Friday are dispatched the same day.\u003c\/p\u003e","products":[{"product_id":"seizaiken-sr521sw-silver-oxide-watch-battery-genuine-japan-made-379-long-lasting-power","title":"Seizaiken 379 \/ SR521SW Silver Oxide Watch Battery","description":"\u003cp\u003e\u003cstrong\u003eSeizaiken 379 \/ SR521SW Silver Oxide Watch Battery\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eKeep your timepiece running accurately with the Seizaiken 379 \/ SR521SW silver oxide cell. Stable voltage and leak‑resistant design for dependable performance.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBattery size:\u003c\/strong\u003e 379 \/ SR521SW\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemistry:\u003c\/strong\u003e Silver Oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse:\u003c\/strong\u003e Suitable for a wide range of analogue and digital watches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShelf life:\u003c\/strong\u003e Fresh stock, typically 3–5 years\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Single retail pack (brand new, factory sealed)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eTip:\u003c\/em\u003e Check your existing battery code or watch manual before ordering.\u003c\/p\u003e\n\u003cp\u003eFast UK dispatch from Chrono Straps UK.\u003c\/p\u003e","brand":"Seizaiken","offers":[{"title":"Default Title","offer_id":51360166478166,"sku":"SEIZAIKEN_379_SR521SW","price":2.67,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0939\/1439\/9062\/files\/Seizaiken_by_Seiko_379_SR521SW_Silver_Oxide_Watch_Battery.png?v=1762695387"},{"product_id":"seiko-379-sr521sw-1-55v-silver-oxide-mercury-free-watch-battery-made-in-japan","title":"Seiko 379 \/ SR521SW Silver Oxide Watch Battery","description":"\u003cp\u003e\u003cstrong\u003eSeiko 379 \/ SR521SW Silver Oxide Watch Battery\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eKeep your timepiece running accurately with the Seiko 379 \/ SR521SW silver oxide cell. Stable voltage and leak‑resistant design for dependable performance.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBattery size:\u003c\/strong\u003e 379\/ SR521SW\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemistry:\u003c\/strong\u003e Silver Oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse:\u003c\/strong\u003e Suitable for a wide range of analogue and digital watches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShelf life:\u003c\/strong\u003e Fresh stock, typically 3–5 years\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Single retail pack (brand new, factory sealed)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eTip:\u003c\/em\u003e Check your existing battery code or watch manual before ordering.\u003c\/p\u003e\n\u003cp\u003eFast UK dispatch from Chrono Straps UK.\u003c\/p\u003e","brand":"Seiko","offers":[{"title":"Default Title","offer_id":51368315519318,"sku":"SEIKO_379_SR521SW","price":2.46,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0939\/1439\/9062\/files\/Seiko_379_SR521SW_Silver_Oxide_Watch_Battery.png?v=1762698988"},{"product_id":"maxell-379-sr521sw-1-55v-silver-oxide-mercury-free-watch-battery-made-in-japan","title":"Maxell 379 \/ SR521SW Silver Oxide Watch Battery","description":"\u003cp\u003e\u003cstrong\u003eMaxell 379 \/ SR521SW Silver Oxide Watch Battery\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eKeep your timepiece running accurately with the Maxell 379 \/ SR521SW silver oxide cell. Stable voltage and dependable performance.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBattery size:\u003c\/strong\u003e 379 \/ SR521SW\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemistry:\u003c\/strong\u003e Silver Oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse:\u003c\/strong\u003e Suitable for a wide range of analogue and digital watches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShelf life:\u003c\/strong\u003e Fresh stock, typically 3–5 years\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Single retail pack (brand new, factory sealed)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eTip:\u003c\/em\u003e Check your existing battery code or watch manual before ordering.\u003c\/p\u003e\n\u003cp\u003eFast UK dispatch from Chrono Straps UK.\u003c\/p\u003e","brand":"Maxell","offers":[{"title":"Default Title","offer_id":51369969615190,"sku":"MAXELL_379_SR521SW","price":3.16,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0939\/1439\/9062\/files\/Maxell_379_SR521SW_Silver_Oxide_Watch_Battery.png?v=1762510200"},{"product_id":"murata-379-sr521sw-1-55v-silver-oxide-mercury-free-watch-battery-made-in-japan","title":"Murata 379 \/ SR521SW Silver Oxide Watch Battery","description":"\u003cp\u003e\u003cstrong\u003eMurata 379 \/ SR521SW Silver Oxide Watch Battery\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eKeep your timepiece running accurately with the Murata 379 \/ SR521SW silver oxide cell. Stable voltage and dependable performance.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBattery size:\u003c\/strong\u003e 379 \/ SR521SW\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChemistry:\u003c\/strong\u003e Silver Oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse:\u003c\/strong\u003e Suitable for a wide range of analogue and digital watches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShelf life:\u003c\/strong\u003e Fresh stock, typically 3–5 years\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Single retail pack (brand new, factory sealed)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eTip:\u003c\/em\u003e Check your existing battery code or watch manual before ordering.\u003c\/p\u003e\n\u003cp\u003eFast UK dispatch from Chrono Straps UK.\u003c\/p\u003e","brand":"Murata","offers":[{"title":"Default Title","offer_id":51374797947222,"sku":"MURATA_379_SR521SW","price":3.14,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0939\/1439\/9062\/files\/Murata_379_SR521SW_Silver_Oxide_Watch_Battery.png?v=1762708213"},{"product_id":"renata-379-sr521sw-1-55v-silver-oxide-mercury-free-watch-battery-made-in-switzerland","title":"Renata 379 \/ SR521SW Swiss Made Silver Oxide Watch Battery","description":"\u003cp\u003e\u003cstrong\u003eRenata 379 \/ SR521SW Swiss Made Silver Oxide Watch Battery\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eKeep your timepiece running accurately with the Renata Swiss Made 379 \/ SR521SW Silver Oxide Watch Battery. High quality Swiss Battery, Stable voltage and leak-resistant design for dependable performance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBattery size:\u003c\/strong\u003e 379 \/ SR521SW \u003cbr\u003e\u003cstrong\u003eChemistry:\u003c\/strong\u003e Silver Oxide \u003cbr\u003e\u003cstrong\u003eUse:\u003c\/strong\u003e Suitable for a wide range of analogue and digital watches \u003cbr\u003e\u003cstrong\u003eShelf life:\u003c\/strong\u003e Fresh stock, typically 3-5 years \u003cbr\u003e\u003cstrong\u003ePackaging:\u003c\/strong\u003e Single retail pack (brand new, factory sealed)\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003ePlease note:\u003c\/strong\u003e Renata batteries may be supplied in either \u003cstrong\u003ewhite\u003c\/strong\u003e or \u003cstrong\u003eblue\u003c\/strong\u003e genuine Renata blister packaging depending on the manufacturer's wholesale packaging. The battery supplied is identical in specification and quality.\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTip:\u003c\/em\u003e Check your existing battery code or watch manual before ordering.\u003c\/p\u003e\n\u003cp\u003eFast UK dispatch from Chrono Straps UK.\u003c\/p\u003e","brand":"Renata","offers":[{"title":"Default Title","offer_id":51763972211030,"sku":"RENATA_379_SR521SW","price":2.9,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0939\/1439\/9062\/files\/Renata_379_SR521SW.png?v=1762299616"}],"url":"https:\/\/www.chronostraps.co.uk\/collections\/379-sr521sw-watch-battery.oembed","provider":"Chrono Straps UK","version":"1.0","type":"link"}