Power supply - anyone using NICAD's?

Finally bought a FF for the Hobie - a Cuda 242 from Sportsmans Warehouse for $60.

Was thinking about power supply, was planning on the new school AA rechargeables was rooting around looking to see if I had a charger and found an old Makita battery and charger from a drill I lost or had stolen a long time ago.

The one I have is a 9.6V so probably no good, but there are 12v units out there (DeWalt for example) - any reason why one of them wouldn't work?

SC

Most fish finders have a lower end voltage at which they stop working,  it should be in your manual so you might want to double check it (my Cuda runs on 10-17 volts).  As for the 12 v units, they should work just find, but you'll want to pay attention to the amp hour rating and the amperage your fish finder runs at.  Assuming the Cuda 242 is similar to my Cuda it should draw 170 ma (back light off), 240 ma (lights on).  If you want your fishfinder to run at least a full 8 hr day you'll probably want a battery with a rathing of about 2 Ah (8 h *.24 A = 1.92 Ah).

The cordless drill batteries I can find online run about 1400 mAh or 1.4 Ah which should run the fish finder for a little over 8 hrs if you don't use the back light and just under 6 with the light on.

Of course I'm not sure how you'd make nice connections to a drill battery.

Brian

Problem is that those cordless drill batteries are expensive and require a special charger.

Just go by your local Batteries Plus store and pick up one of the small 12 volt batteries used in children's toy cars.  Various models, I got one of the larger ones and can run by Eagle Cuda 250 for at least 20 hours per charge (I've never actually run out of juice for it).

I picked up the stuff to do the AA rechargeable battery pack.  I have been using a lawn mower battery in the interm,  I think it is 10 lbs.  anyway all the stuff I needed except the batteris and tupperware I picked up at radio shack for 5.00.  I plan on using the enigizer rechargeables they say they are rated at 2500 mah.  walmart has a 3pack of the lockable tupperware cantainers for 6.97 and they look to be just the right size. they only thing I think I will differnt that spot is use a little marine goop to glue down a 2" web strab to the inside of the boat the add a buckle so I can lock the pack in place.

Carl

oh oh i got a suggestion
i use to use these for starting my gas powered r/c cars and my buddy uses them for starting his helos

they are fairly inexpensive and sealed and charge over night...only problem i can see is weight let me find a weight on them

oh i found it they weigh 5.25 pounds 6" long 3 inches wide and 4 inches tall
12 volts 7Ah batteries

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXL370&P=0

its 19.98 at towerhobbies but i am willing to bet u could find it cheaper somewhere else

plus ull need a charger for around 12 bucks

there is also a smaller 4.5 Ah version that is less then 4 pounds

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXSK06&P=0

do you guys think these would work well?

Those RC batteries would work just fine.  The smaller and lighter the better.  I have two sealed batteries myself (a.k.a. old school power supply) and one is a 7 Ah brick that weighs about 7-8 lbs and the other is a 4.5 Ah that is a bit smaller and weighs in at about 3-4 lbs.  I've never had  a problem with either of them.  Okay that's not true.. I once went to grab the 7 Ah battery while I still had my keys in my hand as I was getting out of my truck..  my keys made the connection and I got a nice zap, a burnt spot on my calloused hand and a weld spot on my key.  Never made that mistake again.

Brian

I use those 7Ah batteries.  No problems.  Make sure to get a charger with the auto-shutoff feature as those batteries will go bad quickly if overcharged.  Ask me how I know.   

-Allen

My charger doesn't have an auto-shutoff, rather it's a fairly slow charger 260 mA.  Because it's charge rate is about the same as what fish finder discharges from the battery I just charge it an equal amount of time.  For example, if I had the fish finder running for 4 hours, I charge the battery for 4 hours when I get home.  If the battery is completely dead I give it a full days charge (7 Ah / 260 mA) ~= 26 hrs.

Anyway, the auto-shutoff is nice if you can get one.

Brian

ya imo i would rather just have the one battery cause i am lazy lol...plus with the extra pounds u can run your finder for about as long as u want with light on and what not...but then again there is the problem of welding your keys to the terminal

My power supply is exactly like the RC car model linked above, but a 9 Ah model instead of 7.  Only problem I ever had with it was when I dropped it and cracked the tupperware container I store it in (nothing a little marine goop couldn't fix).

neophyte that i am, and avid adherent to 'bigger is better' [ most of the time] i had been looking at the optima spiral cell batteries, yello top marine grade.     .oooppssss....47 lbs   

A good thing about rechargable AA nimh's is you can use 12-14 batteries(NIMH's are 1.2 volts) and have some extra voltage and get some extra life without too much extra weight, if your finder will handle the extra voltage like the Eagle cuda's do. It is a little bit of a pain to charge the batteries if you only have a charger that accepts four batts. at a time like me. More chargers are just not high on the priority list at this time so i deal with it.

u can also use a 12v deer feeder battery they run like $ 10 at tractor supply or harbor frieght