Nitecore UM4 Battery Charger
https://owlsense.odoo.com/shop/nitecore-um4-battery-charger-20
https://owlsense.odoo.com/web/image/product.template/20/image_1920?unique=efd2a9f
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Our recommended charger for 4 or more Owl Sense units.
This is our recommended 4 cell battery charger. It can charge 4 batteries in about 4 hours. Requires a 2 amp QC USB input.