Broosky I don't know what you have for a charger, if it's a car charger type, use it on a low slow charge.....You can also use a cell phone type charger. If you charge the battery to fast or with high amperage, you may cook the battery.
i do. this type of small battery will power it up all day long. i need to add an inline fuse though. i went all year without one last year but just got lucky.
http://store.humminbird.com/products/322329/GCBK