10-23-2008, 12:10 AM
So I wanted a convenient battery for use on my 'toon for my Humminbird fishfinder. I considered a small sealed lead-acid battery, but they're still quite heavy and charging isn't the most convenient.
What I ended up doing was using a Craftsman 19.2V rechargeable drill battery. I have two for my tools and the charger is quick and easy - drop and forget.
At full charge, the batteries read over 20v, and since the Humminbird shuts down at over 20v, I used a 7812 voltage regulator chip (you can get 'em at Radio Shack) to step the voltage down to 12v. Standard spade terminals push on the terminals on the battery (use a meter to figure out which of them are pos/neg).
I started it up last night and the battery finally died after over 18 hours of continuous running without the backlight on. Plenty of juice for a day of fishing.
Just throwing out an option for those with sonar and no motor...
_SHig
[signature]
What I ended up doing was using a Craftsman 19.2V rechargeable drill battery. I have two for my tools and the charger is quick and easy - drop and forget.
At full charge, the batteries read over 20v, and since the Humminbird shuts down at over 20v, I used a 7812 voltage regulator chip (you can get 'em at Radio Shack) to step the voltage down to 12v. Standard spade terminals push on the terminals on the battery (use a meter to figure out which of them are pos/neg).
I started it up last night and the battery finally died after over 18 hours of continuous running without the backlight on. Plenty of juice for a day of fishing.
Just throwing out an option for those with sonar and no motor...
_SHig
[signature]