Fishing Forum

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
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If you go to Battery Specialists, you'll find the lead sealed batteries in different configurations. I don't know what SLA battery you're looking at that you say is too heavy for a tube or kicker, but the ones I have are pretty light. I have one that I use that's the size of a 2"x4" by 6" long (I think it's for a home burgular alarm system). I have a cheap 110v charger that clips on the "posts, and I have a cigarette lighter car charger that'll charge it up in a couple hours- no inconvenience at all- and I'm lazy. That battery will last over 3 days without charging. With the SLA battery you don't have to mess with voltage regulator, and you don't have to buy another battery for your drill. I wouldn't think of using my DeWalt drill battery on my fishfinder. Way too bulky and expensive. Maybe the Craftsman's cheaper and slimmer. Don't know. Also the cool thing about the slimline SLA it fit's in the back of my H3, and Navi II back pouchs or it just sits on my kickboat deck, minding it's own business. In fact, I tap into it the same time with my GPS.
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I have a thin one also. Home Alarms battery. Small and killer.


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Hmm... Good info. I just happened to have these batteries (2 19.2s and 1 14.4) lying around and I can get the regulators from work so I made do with what I had.

The SLA I have is 3" x 3" x 4" so really it's not THAT big, and not much larger than the drill batts. I just don't have the right trickle charger for it and I figured I'd blow it up using my car battery charger!

One thing I also am considering is an 10-gang AA NiMH set which would be super light and compact and have more energy (2.2-2.6 Amp-hours vs 1.5 Amp-hours) than even my bigger drill battery. The SLA does have 4.5 AH though so it does win the endurance challenge.

Got any links to the chargers you guys use?

_SHig
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I would bet any of these would work. I have the $13. one but bought it at a warehouse for like $2.00.

http://www.apexbattery.com/home-security...eries.html
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Yeah, I'm finding (on Ebay) a bunch of small batts that'll easily last a day or two for less than $20 shipped that'll work great.

I'll use my drill batts for now since they work but I'm going to keep an eye out for a cheap SLA charger. Got other things to buy for now, but one day I'll switch over.

_SHig
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