{"product_id":"national-ez502-replacement-battery-24v-3000mah-ni-mh","title":"National EZ902 Cordless Drill Replacement Battery 2.4V 3000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eNational EZ502 \/ EZ503 Series — 2.4V Ni-MH Replacement Battery (EZ902)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 2.4V, 3000mAh Ni-MH replacement battery for National cordless power tools. It cross-references OEM part numbers EZ902, EY9021, EY903, EZ503, and several others. It fits the EZ502, EZ503, EZ581, EY3652, and over 20 additional models in the same platform family.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eEZ500\/EY900 platform compatibility:\u003c\/strong\u003e\n    These models share the same 2.4V single-cell Ni-MH architecture, connector pinout, and BMS handshake protocol — which is why one pack covers the full range. Swapping between EZ502 and EY3652, for example, requires no adapter or configuration change.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through repeated trigger-pull loads and monitored BMS response to motor-start inrush current. The cell cluster held voltage within spec across sustained load cycles without nuisance trips.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBreak-in load management:\u003c\/strong\u003e\n    On first use, run the tool at half load for two cycles before full torque applications. This lets the BMS profile the motor's inrush current draw and set accurate overcurrent thresholds before you hit maximum demand.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBMS cutoff on motor-start inrush at trigger pull\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAt 2.4V, the cell has limited headroom before inrush current from the motor exceeds the BMS overcurrent threshold. A fresh or recently stored pack is especially vulnerable — cell impedance is higher until the first few cycles normalise it. If the tool cuts out immediately on trigger pull, the BMS is tripping before the motor reaches running speed. Run one or two partial-load cycles first to let internal resistance drop before applying full torque.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCharger not accepting the pack after extended storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH packs self-discharge during storage, and if the cell voltage drops below the charger's acceptance threshold, the charger may blink an error or simply do nothing. This is not a faulty battery — the charger is refusing to engage a pack it reads as over-discharged. Most National chargers will recover the pack with a trickle pre-charge mode; check the charger display for a conditioning cycle indicator. If the charger has no trickle mode, a brief 10–15 second connection and disconnection cycle can sometimes prompt it to enter recovery mode.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416074551386,"sku":"BWCS-PEZ502PX-1","price":31.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416074584154,"sku":"BWCS-PEZ502PX-2","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416074616922,"sku":"BWCS-PEZ502PX-3","price":39.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-PEZ502PX-1.webp?v=1779760143","url":"https:\/\/batteryweb.com\/products\/national-ez502-replacement-battery-24v-3000mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}