Fish Hawk Lithium Pro ProbeCharging Ahead! The Fish Hawk Electronics Lithium Series incorporates four decades of experience with the lithium power anglers expect in modern electronics. The new, maintenance free probe is 40% smaller than its predecessor and provides more than 50 hours of fishing time on a single full charge. Underwater currents make trolling speeds at depth unpredictable. Temperature throughout the water column can change dramatically. Fish Hawk Electronics