{"product_id":"tomtom-star-20-replacement-battery-37v-700mah-li-ion","title":"TomTom Star 20 Replacement Battery 3.7V 700mAh ALHL03708003","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eTomTom Star 20 \/ Star 25 Series — 3.7V Li-ion Replacement Battery (ALHL03708003)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 700mAh Li-ion cell built to fit the TomTom Star 20, Star 25, 4EN42, and 4EN.001.02 portable GPS navigators. It replaces the original ALHL03708003 battery in units that no longer hold a charge or shut off unexpectedly. Capacity matches the factory spec — 700mAh, 2.59Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eStar 20 and Star 25 compatibility:\u003c\/strong\u003e\n    Both models share the same compact 35 × 35 × 5mm cell footprint, voltage rail, and connector pinout, which is why a single SKU covers the full range. The BMS thresholds and charge termination voltage are identical across this device family.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge and discharge on the Star 20 platform. The BMS accepted charge without fault codes, and cutoff triggered cleanly at the low-voltage threshold rather than dropping mid-session.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eCold start after power interruption:\u003c\/strong\u003e\n    After fitting this cell, power the GPS on outdoors before driving. The unit performs a full cold start after any complete power loss — first satellite acquisition takes 5–10 minutes. Subsequent warm starts drop to under a minute once the almanac is cached.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eGPS accuracy reduced at low battery on the Star 20\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the Star 20 battery drops below roughly 3.5V, the unit can reduce GPS receiver sensitivity to conserve power. This shows up as position drift or a weakened satellite signal count on the status screen. It is not a hardware fault — it is a firmware power-saving behaviour tied directly to battery state. Keeping the battery above 3.6V during active navigation prevents the receiver from stepping down sensitivity.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eStar 20 shuts off without a low-battery warning\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAfter a battery swap, the fuel gauge IC inside the device needs one full charge-to-discharge cycle to recalibrate its voltage-to-percentage mapping. Until that cycle completes, the displayed battery indicator can read 30–40% and then cut off seconds later. This is not a faulty cell — it is an uncalibrated threshold. Run the unit from a full charge down to automatic shutdown once, then recharge fully, and the warning indicator will align correctly with actual remaining capacity.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43377645584474,"sku":"BWCS-TMS25SL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43377645617242,"sku":"BWCS-TMS25SL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43377645650010,"sku":"BWCS-TMS25SL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-TMS25SL-1.webp?v=1778771783","url":"https:\/\/batteryweb.com\/products\/tomtom-star-20-replacement-battery-37v-700mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}