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Ken L

Fish finder batteries.

13 posts in this topic

In my rush to get the Sidefinder up and running I didn't give batteries much thought. I used two lantern batteries that I more or less duct taped between the scupper posts below deck. So far so good as the sidefinder has a low battery indicator and after about 12 hrs it has yet to show itself. AT $6 OR $7 apiece this is not a good permanent solution. I followed Bobp's example as a result and bought a Gel-Cel at a hobby store. This is a better way to go but there are some things to watch out for. First of all the Sidefinder draws about 1/2 amp so in my typical outing of 4hrs I will use 2 amp hrs. Well you can usually get 3, 5, or 7 amp/hr capacities. The problem is that the useful life of a lead acid battery is a function of how deeply it is discharged. There is a need for compromise here and 50% discharge seems to be the best recommendation. So I could choose a 5 amp/hr and get away with it. But... Another issue is the length of time the battery stays discharged. The sooner it is brought back to full charge the better. I chose the 7 amp/hr because, while I won't likely discharge it below 50% very often, I may have to leave it discharged for longer than I would like on occasion. The closer it is to full charge during these times the better.

Another point on Gel-Cels is the charger. There are limits to how quickly the can be recharged. You have to use a charger designed for the purpose. The one I use for my trolling motor battery or my car could ruin it quickly.

The final point is that most electronics store s have cheap DIGITAL volt meters which are the equivalent of gas guages on batteries. There are tables available that can tell you pretty much within a few percent of where you stand.

Properly maintained a lead acid battery should last for years but without good care they could last a few outings.FWIW

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Ken,

 

I think you are thinking about this battery thing too much. First off, you can buy sealed lead acid batteries (not the gel cells you have) that are cylindrical and they are made by Gates or Cyclon. You can get them in surplus stores and new from electronics stores like Digi-key (top knotch assortment, always in stock, but pricey). They come in 2.5 and 5.0 amp hour capacities which is more than your requirements. These batteries will take a deep discharge and fast recharge without boiling out the electrolyte.

 

For gel cells, after you finish your fishing trip, you can hook up a float charger to the battery to bring it back up to 100%. Also, they do come in 4 Ahr capacities and mfgs like Panasonic and Powersonic comes to mind right away. You can get brand new or New Old Stock (NOS) from places like Parts Express at very reasonable prices. My 17Ahr batteriy with a 1998 date code cost me $14.95 and it's perfect. As for an extended discharged state, the electrolyte or the battery may not be revived if it drops below a certain voltage (1.1V per cell, if I remember correctly), but I don't let my batteries drain that low to begin with. Almost all batteries including NiCads could/should be charged a the C/10 rate which is 1/10th the capacity of the battery. For your 7 AHr battery, 700mAh or .70 amps would be fine for 12-14 hours once fully discharged (you decide what capacity was used during the day to prorate the time to be recharged). That is why it's no good to use a car battery charger for these gel cells or lower capacity batteries, because the charge rate is too high. If you get a float charger, it will provide a mild overcharge to the battery (that is OK) to maintain 100% once it hits that level. The one DAS has (I think, Das correct me) turns off when it hits 100%. I have a float charger taken from the battery operated emergency lights and it's works just fine. I also have a variable power supply that goes up to 2 amps (good enough for a 20 ahr battery). I usually set the charge rate slightly higher than C/10 when I start because the battery's internal resistance starts off low(er) and increases as it reaches 100% capacity, thus decreasing the amount of juice that gets pumped in. When all is finished, my average charge will be C/10 and I think the rest is immaterial.

 

So I guess the bottom line is get a float charger and hook it up when you unload your tackle and other stuff as part of your post fishing ceremony and don't sweat the rest.

 

Sorry for the long winded response.

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mrsinbad-

 

Is this you longest post on SOL? Seems like it. wink.gif

 

But that's OK, because I'm counting on you gaining all of this knowledge and wisdom (hopefully most of it through trial and erro) so I can pick your brain and have you help me install a FF on Yum Yum!

 

Carry on....

 

------------------

Joe

GO NAVY

g0404980.gif

 

[This message has been edited by JoeB (edited 06-12-2002).]

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Last time it was a breakdown of carbon fibers and now it's complete paper on batteries. I've got a lot of studying to do this weekend..AGAIN! Thank guys wink.gif

 

[This message has been edited by saltyh2ofly (edited 06-12-2002).]

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MrSinbad,

Everything that floats is a compromise as I see it and If we do things differently it doesn't mean either of us is wrong. I did what I did based on hard learned lessons and personal convenience. There seems to be an interest here in this sort of thing and I posted in response to that. Along those lines I also wanted to keep it simple. I think most SOL'ers would like to know what they need to know and no more.

If I didn't anticipate being unable to recharge soon after a day's outing I would have gone with the 5 amp. The 7 being closer to full charge under these circumstances is likely to hold up better. I didn't want to be bothered with mail ordering from an electronics outlet and my thought was that most SOL'ers wouldn't either.

Finally a 17 amp/hr battery probably comes in somewhere around 15 pounds. My Explorer only weighs 40. My days of bench pressing 300 pounds are long gone if they ever were. The less I have to get up on the roof of my truck the better.

Still i don't mean to fault your approach. Whatever works.

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Ken,

 

I absoutely agree with you. Stick with what works for you. Just offering my view and letting you/SOL'ers know of alternatives. I am addicted to surplus buying and tinkering as others that know me will tell you. (It's like Christmas all the time!) So every month, I receive several packages including those black rubber wheels I posted a couple of months ago. My 17 AHr battery is used for my electronics test and rodbuilding bench when and if I need higher current than my variable power supply can provide or if I need motors plugged in for longer periods than I want to have my PS plugged into the wall.

 

Apologies if you felt your toes stepped on. Not meant that way at all. Shake? thumbuprt.gif Damn, no handshake icon!

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So anyone want to recommend a brand of battery? I didn't really want to put a fishfinder on my kayak but I just purchased a second one with the unit installed. No battery came with it so I must pick up a new one. Any suggestions on brand?

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no specific brand I just picked up a 12v 7ah battery at a hobby store. It cost about thirty bucks.

Cabelas sells pretty much the same battery I have. It's listed under fish finder accessories

 

 

 

[This message has been edited by bobp (edited 06-19-2002).]

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I bought one, 12v 7ah at a hobby store in Riverdale on rt23. Not to go one up on Bobp but it was about $22. Make sure you get the charger too. On the other hand my two lantern battry setup is still going strong after at least 20 hrs. FWIW

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I don't recommend you go the route of buying from surplus or discount electronics stores for critical applications like replacing your starter battery for your boat you intend to go offshore fishing in, but if you want to save a few bucks, here is a short list from a few online/mailorder places I have bot from in the past... You can guess what the URL's are for fear of getting slapped by the boss again.

 

BGMicro smile.gif

Herbach smile.gif

Partsexpress smile.gif

 

They will have an assortment of batteries in different voltages, conditions, and capacities with prices that are better and worse than what has been quoted above. Goodluck.

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Thanks guys...now all I need is to pick up another "A" hatch from Jon and I should be set. can't wait to test paddle the new Navigator. Maybe Friday after work. talk to you guys soon.

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Father's Day was relaxing on the home front. Didn't get out to fish and I still haven't ordered the Sidfinder 1250 yet. It's a lot of sheckles for me right now. Maybe in July after the charge cards settle down. frown.gif

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