The Hobie Fish Finder 12v Battery is a rechargeable battery that fits the Hobie Fish Finder connections. Keep a spare battery charged up so you're never caught without your fish finder.
This is my third and last one of these batteries. If you want a battery that lasts a couple of months and then won't hold enough charge to keep you fish finder on then buy this one. I use the Hobie charger, let the battery mostly drain between charges and it still loses voltage output. Far cheaper options out there and I'm switching.