Magic’s Ikea battery holder
The best battery holder I have tested is one of the least expensive and it is easy to build and weighs about 4.8 Oz.


List of materials for battery holder from Ace HW or Ikea
Curtain rod Ikea 002.171.65 $0.99
2 brass 10-32 X 1.5 screws + 4 nuts $2.00
4 Crimp ring terminals $0.25
4 7 inch pieces of braid fishing line 25LB $0.25
2 15 inch pieces 1/8” bungee cord $2.00

List of materials for mounting clips
2 6-32 X 1 &1/2 flat head screws with nuts $1.08
1 wooden yard stick $1.29
2 ½ inch pipe mounts ACE#556-2PK2 4033593 $0.50
4 drops of Amazing Goop $6.50/tube $0.50

Tools required:
Pliers
Fine tooth hacksaw (32 teeth/inch)
Screwdriver
Round file or sand paper
Two 2.5 inch pieces of duct tape
Electric drill
Drill bit between .130 and .150 diameter
Drill bit ¼ or larger
2 or 4 Small spring clamps or binder clips.



Screw the 10-32 screws into the ends of the curtain rod about ¾ inch. Pull the plastic end pieces out of the curtain rods. I had to hook my weak hand over my knee to pull out end piece.
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Take the screws out of the plastic end pieces. Turn the plastic pieces around and put the screws back in. A screw driver will be required to get the screws all the way to the bottom. Put 2 crimp rings terminals on each 10-32 screw. Tighten one nut down with the crimp ring terminals facing away from each other. Add the second nut for safe keeping. Tie the ends of the 7 inch braid together making 4 endless loops. Thread the endless loop through the hole in the crimp ring terminal where the wire would normally go. Put the end of the endless loop through the other end of the endless loop like you were making a larks head

Next will be to cut the smaller diameter rod to length. For 8 Lithium batteries the tube should be cut to 16 &9/16 inches. For 10 alkaline batteries the tube should be cut to 20&1/2 inches.
Place a piece of duct tape around the tube approximately centered over the location where the tube will be cut. Measure and mark on the tape the location to cut the tube. Using a fine tooth saw cut the tube off at the line. (Note a tubing cutter will crimp the tube and not work properly) Using a file or sandpaper remove the sharp edges and burs on the cut surface.



Using the same procedure cut the large tube to 3&1/2 inches from the end of the plastic cone. Once the burs have been removed reinstall the plastic ends in the end of the tubes that was cut, covering any sharp edges. Some plastic ends fit fairly loose if they will come apart too easy put a ½ drop of goop on them to glue them into the pipe.
Tie a simple knot in both ends of the 15 inch bungee cords. If the ends of the bungee are passed near a flame it will stop them from fraying.

Use a Larks head to connect the ends of the bungee to the endless loops. If all is well if you put the correct number of batteries in in the tube just the end of the last battery will stick out.
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Cut 2 one inch pieces off the yard stick. Cut 2 two inch pieces off the yard stick and using goop glue the 1 inch pieces in the middle of the 2 inch pieces. Use the binder clips to hold until the glue is set. Locate a spot ¼ inch from the edge and 1 inch from both end and drill a hole using the small drill bit (.130 to.150). By hand turning the large drill bit chamfer the hole on the end at the surface of the 2 inch piece. Test frequently to make the head of the flat head screw flush with the bottom of the wood. If you have any old outdoor paint use it to paint the wood.

Pull the nails out of the two ½ inch pipe mounts. Using the small (.130 to .150) drill bit enlarge the hole the nail was in. Before assembling place a small dab of Goop on the surface of the wood where the pipe mount will set. Assemble the 2 pipe mounts with the thin plastic away from the wood. The screw is being tightened against a soft wood and if over tightened will pull through the wood. The uncured Goop will leave a slick surface so properly align the pieces and let set until cured. Install mounting blocks by slipping over the end to reduce force on mounting blocks.


To mount in mounting clips in a canoe snap them onto a battery holder to keep them aligned. Tip the canoe so the mounting location is down and clean the spot where it will be mounted. Place a drop or two of goop or bathtub calk on the bottom of the 2 inch clip support and stick in place and let dry.

Very nice, I like the idea of a long holder, great space saver.

... and why do we need a battery holder?

What am I missing?

quote OBX2Kayak: "... and why do we need a battery holder?


What am I missing?"

To run a huge boom box? Or I'm thinking a fish/depth finder

quote OBX2Kayak: "... and why do we need a battery holder?


What am I missing?"

Trolling motor. :)

Yep, he's talking depth finder. He and Rich put on a great presentation on rigging your canoe for fishing.

I have the 2x5 AA battery holder mounted in a pelican box. It is nice, but difficult to secure a brick like that enough for portaging. This design looks easier to secure. I am wondering about BDB to the canoe thwart?

Thanks for the kind words nctry and nice to get together for planning. The talk came of ok after the technical glitch. It all worked Friday when we hooked the same computer up and displayed the same power point.

quote NotLight: "

I have the 2x5 AA battery holder mounted in a pelican box. It is nice, but difficult to secure a brick like that enough for portaging. This design looks easier to secure. I am wondering about BDB to the canoe thwart?


"

Look closely at the first picture just to the left of the left mount and you can see a plastic collar. The plastic collar and what is to the left of that must slide on what is to the right. Another way to describe it is it is a pipe over a pipe. After mounting the two pipes must be free to slip over each other to maintain contact with the batteries. If the mounting clips are used or spacers of some kind are placed between the thwart and the longer white tube it would work.
BTY the curtain rod comes in white, black, and tan.

quote MagicPaddler: "BTY the curtain rod comes in white, black, and tan.
"

Thanks, MP... always looking out for the color conscious paddler.
Ingenious design.

MP. Now that your back...

I got a new fishfinder and GPS. Lowrance Mark-4, no downimaging, plus GPS. It uses 130-190mA, depending on the backlight setting. This draws almost 2x the power of my old Garmin 101 fishfinder, which draws 110-130mA. It has been running fine on 8 AA Eneloop batteries.

But I'm thinking about using 3 of the Nitecore 18650 batteries in series instead, and making this holder. My issue is, can I put 3 of those batteries in series? My other issue is, do I need to worry about lithium batteries and fires/explosions? Opinions? Thanks. The Nitecore batteries seem a lot cheaper than when I looked at them last year.

So I'm not that well versed on electronics. Can you really run a vexilar off of just AA batteries like this? How many do I need? Lastly, how many hours can I run it on just a few AA batteries?

There's probably a Khan academy video that describes it better. But, I always describe a battery/electricity as being like a waterfall of electrons. The "voltage" of the battery is like the height of a waterfall and "electrical current" from the battery is like the amount of water flowing over the waterfall. Another way to describe a battery is like a bucket of water. The voltage of the battery is like how high you raise the bucket off the ground, and the electrical current is like how fast you pour water out of the bucket. The battery capacity is just like the size of the bucket in gallons.

To continue with the bucket analogy. How fast you pour water out of your bucket in electrical terms is measured in Amps, or with fish detectors typically milliamps (1/1000 of amps). Typical fish detectors seem to flow from about 100milliamps up to 500ma of current when they are switched on. The battery capacity - kind of like a buckets capacity in gallons - is measured in "milliamp-hours". To explain what milliamp hours is... suppose you pour 100ma of electrical current out of your battery for 1 hour, and then your battery runs dead. That means, you have 100milliamps x 1hr = 100 milliamp-hours of battery capacity. If you have a bigger battery that lasts 10 hours drawing that same amount of 100milliamp current until it goes dead, then you have a 100 milliamp x10 hr = 1000milliamp-hour battery. AA size batteries seem to range in capacity from 500milliamp-hours, up to about 2400milliamp-hours.

So yes you can power a fish detector with AA batteries. For how long? It depends. The cheapest depth finders with black and white screens and no down scanning or gps draw about 100milliamps. A typical AA battery with 1000milliamp-hours of capacity will power that fish finder for about 10 hours. I do not know how much power your Vexilar uses.

The problem is, fish finders are designed to run at 12V, and AA batteries are only about 1.5V at most. So you need to stack from 8-10 batteries together end to end to get enough voltage to turn your detector on. When you stack batteries end to end, you don't get more battery capacity, unfortunately, just higher voltage.

There are AA battery holders you can buy on amazon that will hold 8-10 AA batteries.
The design in the posts above is just a different way to do it.

Sorry for the long post, or if that doesn't make sense.

Wow that's impressive. Thanks for the great write-up. This seems like an excellent alternative to lugging around a 12v brick. I might have to try this :)... Assuming you can get enough life out of a stack. Fl-8 by the way...

quote Grizzlyman: "

quote NotLight: "There are AA battery holders you can buy on amazon that will hold 8-10 AA batteries. The design in the posts above is just a different way to do it.

Sorry for the long post, or if that doesn't make sense."

Wow that's impressive. Thanks for the great write-up. This seems like an excellent alternative to lugging around a 12v brick. I might have to try this :)... Assuming you can get enough life out of a stack. Fl-8 by the way..."

Looks like the FL-8 draws about 250 milliamps of current when it is on. So, if you had a 2000milliamp-hour AA battery setup, the flasher would only run for about 8 hours (2000 milliamp-hours/250milliamps=8hours). I am getting about the same performance with my detector. This is OK, because I'm not enough of a fisherman to bring the thing on a BWCA trip. But, I am looking for something a bit better.

Links:

2000mah batteries
Battery charger
Battery Holder
Battery connector thingamajig

Here's a picture of the last one I made. But now I am trying to try MagicPaddlers design above.

Not light I like your water analysis but let me add one more thing to it. Your fish detector requires between 10 and 16 feet of head to produce the pressure (voltage ) it needs to operate. Each alkaline battery is labeled 1&1/2 foot of head (volts) but if you measure it you will find a new battery has about 1.6 feet of head (voltage) and as you use the water out of it the head (voltage) goes down. It will supply quite a bit of water (mAh) per inch of head loss until the head gets down to about 1 foot (volt). Then removing any more water (mAh) will cause the head to drop to zero.
The above explanation uses values of an alkaline battery. Other battery technologies have different values but still have the loss of head (voltage ) as the battery is discharged.
Now for 18650 batteries. The ad states it is a 3.7 V battery and has internal PCB protection. By the battery voltage and protection levels I can tell this is a Li-Ion or Li-polymer or Lipo battery. These batteries NEED PROTECTION and the battery in the Amazon ad I looked at said they had built in protection. Word of caution batteries of this technology are commonly sold without protection. Without protection you will most likely destroy the battery the first time you discharge it and they frequently catch fire when over charged.
Remember from above your detector requires between 10 and 16 feet of head (voltage) to operate well. After charging each of these cells will put out about 4.25 feet of head (volts). As the battery is used the head will slowly go down until it gets down to 2.5 feet of head (volts) at which time the protection circuit will shut the flow of water off (open the circuit).
I have been using LiPo batteries to power a detector for non wilderness fishing for a couple of years. My battery came without protection and I have purchased a separate protection board and power my electronics through it. The board I purchased also has over charge protection.

Wow- so I was so impressed that you can do this that I went out and made one for about $5 and yep, it works swimmingly. I've got it clipped onto my thwart...sure beats lugging around the old 12v brick. Thanks for the post I'll post a pic tonight.

quote Grizzlyman: I've got it clipped onto my thwart... "

Grizzlyman
If you tie it directly to the thwart make sure the end cap is free to move so it will stay in contact with the batteries as it heats up and cools down.
MagicPaddler

P.S.
If you made it for 8 batteries use Energizer Ultimate Lithium batteries.
If you made it for 10 batteries use alkaline batteries. Best deal is Ikea batteries.

Magicpaddler, I modified mine so it's different but similar. Thank you for giving me the idea. I'm using alkaline batteries and I need 10 to power the vexilar. I used 1/2" PVC- this fits a AA surprisingly well. I put a female coupling to accept a screw-on end cap on the ends. Then it's simply drilling a hole through the screw cap and putting brass bolts through. I glued a small junk spring and connected to the bolt on the negative end. Simply load w batteries and screw until tight. After I was done I painted bronze gold to look good with the cedar strip :) (looks like I need one more coat) I have alligator clips on the vex which will then clip onto the bolts.

The PVC mounting clips are screwed into a "utility bar" which I have bolted to the thwart. This utility bar now holds my trolling rodholder on top, snap in battery facing me, and I think I'm going to put another tube with just end caps on it the other side of the bar facing away just to hold one more extra set of batteries.

Thanks again for the idea Magicpaddler.

I would strongly advise against LiPo batteries. I run them in some RC stuff I have and they can not only catch fire during charging but during discharge,less common, and plain old storage. The fire is more like what it looks like when you light a firecracker that's had the end cut off.

I store and charge mine in a special fireproof bag. Granted the discharge rates on mine are higher than what would be needed for a fishfinder.

If you do decide to go that route be sure to encase them in something and frequently check them for "puffing", they will look swollen.

Probably a dumb question...but I'm curious if the brass screws in this set up get wet, will it will be a problem??

You never want water around electrical connections but brass does not corrode badly with clean water on it. I took one of the Ikes holders and put bathtub calk on the end plastic pieces then put it together. I put batteries in it and put in a tub of water and shook it. Took it out dried the outside and opened it up to only find a drop of water in side that I think went in as I took it apart. Rain had never caused a problem with mine.