Small deep cycle batteries?

[311Hemi]

Can anyone point me in the right direction to find the smallest deep cycle battery.....or at least one of smaller size?

[sparcebag]

What voltage?For outboard,elec.motor, lights etc.???

[311Hemi]

Need it to run an old 12v electric trolling motor for 20-30 min. Just enough to get across a slew and back.....light weight is the biggest concern as I have a smaller duck boat (Alumacraft Ducker) that the edges sit very close to the water when loaded.

Also would be used in the truck to run an AD/DC converter for fans on the dog kennels.

[so haaad]

You could run your trolling motor on your Vexilar/flasher battery. They sell the small ones that are only about 5lbs or so at Fleet and other sporting goods stores.

[311Hemi]

Thats what I was wondering.....

BTW....I am running an old Minn kota 65 which has 28lb thrust.

[Whoaru99]

Hmmm... don't know that I'd try the Vex battery.

Those trolling motors draw a fair amount of current and just might put too much load on that tiny battery leading to internal damage. I don't know that for fact, but those Vex batteries are pretty small...

Using say four or six in parallel MIGHT be an option, but I make no vouch for performance, and even that may be a stretch.

[311Hemi]

Yea...that is why I am looking for a small deep cycle...if there is such a thing. I will have to call around.

[Whoaru99]

There are smaller ones, group 24 comes to mind, but that's still fairly big and heavy.

They do make larger SLA (vex-style batteries), but they're not real cheap. Depending on the size, anywhere from $50 to >$100.

Might want to check into a battery for one of those electric wheel chairs or something like that. Dunno what they use, but it just popped into my head as a possibility.

[Whoaru99]

I'd think something like 30AHr, give or take, would work; again, never tried it.

[311Hemi]

Batteries plus has some 12v ones for the powered wheel chairs for $70. I think that will work. They are smaller like the vex batteries.

Thanks for the info!!!

[Shack]

When in doubt, I would think a lawn mower battery could handle you needs. They are cheap and last awhile. If you charge them up. $70 bucks seems high, I would try a $15-$25 dollor Wall-Fart battery first.

Good luck!

[Whoaru99]

Well, don't get carried away with trying to go too small. Anything that is the size of a vex battery is too small, IMO.

Regardless of anything else, it still needs to get the job done.

Another option is to look at some of the electrical/electronic surplus stores if you have any near your location.

[sparcebag]

First of all you should find out what your minkota draws as power,then you could have an idea of what battery your looking for.My guess is that the vex battery would last just as far so you'd have to row.There it is get some oars,a paddle,if the slew is so small row.

[iffwalleyes]

Do you have a vex battery? If so hook it up turn it on and time how long it lasts. If it make better than your time you should be ok. You need to look at the amp hour of a battery. Lots of vex batteries are 7.0 ah. That is smaller but you can find larger ah batteries that will give you longer run time. I really think you can make the vex battery work for you. Even if you carried two vex batteries. It would be lighter than any other battery combination.

[Whoaru99]

Yes, most are 7Ah, but the thing to remember is that 7Ah is at a relatively low discharge rate. If you suck power from it at 7A rate, the battery provides that for only about 35-40 minutes.

[Whoaru99]

Quote:

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First of all you should find out what your minkota draws as power,then you could have an idea of what battery your looking for.

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This is the bottom line. In order to pick the smallest battery that will get the job done we would need to know the draw of the motor.

Just keep in mind it will be more draw when pulling/pushing a boat loaded to the gunnels than it will just spinning the prop in air on a bench test.

[311Hemi]

Thanks for the info guys!

It's an old Minn Kota 35w (17 lb thrust). The boat is only 12" deep, flat bottom, 12' long, pointed on both ends.

Draw:

25 amps on 4 speed

17 amps on 3 speed

14 amps on 2 speed

10 amps on 1 speed

I would not run on 4 much if at all....most likely 2 or 3.

I think a smaller wheel chair battery (35ah or 33ah) would be the best bet.

[so haaad]

I've had to run my trolling motor on my vex battery before. (Let's just say that I was up a creek without...I mean...up a creek with only one paddle and I spun a prop.) I believe my old Minnkota 65 (28lb) ran for 45+ minutes. The vex battery may not be the best option, but it's a cheap method. Get one at Ax-man in Fridley for 12.95 and you are set. Just north of Moore Lake on Central Ave.

[Whoaru99]

You can get 28Ah sealed batteries from DigiKey for ~$50 (plus shipping). The 33Ah are about $67.

Considering shipping, $70 from Batteries Plus isn't too bad for a 33-35Ah battery - assuming it's the sealed type (technical name VRLA - Valve Regulated Lead Acid).

[sparcebag]

311 is that the minkota with the transducer built in and a cheap looking depth display? I once ran mine on two 6V batteries out of a eagle portable,they lasted exactly 15 minutes.I was timed cause my buddy said it would'nt work,of course they were nonrechargable batts.

[311Hemi]

Quote:

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311 is that the minkota with the transducer built in and a cheap looking depth display?

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Nope....nothing that high tech! Just a switch for forward/reverse!! LOL

[Gator Slayer]

Fleet Farm has a small garden tractor sized marine rated deep cycle for ~35$ if I remember right. I don't recall what the AH rating was but a call to your nearest mill's would answer that for you.

[Whoaru99]

If we do the math, you should be able to get by with 15-20Ah.

Assume worst case...

25 on #4, run time 30 minutes, some cushion because we don't really want to row.

25 x 0.5 = 12.5Ah. 12.5Ah + 25% = 15.6Ah

Bare minimum seems two vex batteries, but at such a high discharge rate, they don't really do 7Ah. You'd be down to 10V in about 15min according to some Panasonic discharge curves I've looked at.

The same data shows a 33Ah battery would be down to 10V in about 40min under the same load.