There has been several people looking for a good rechargeable battery to use for a portable fish detector. There has been a technology around for several years but it was not easy to use them safely without a lot of expense. Lately I have been seeing protected cells at better prices. I have purchased a couple of sets of cells and done some testing and I believe they will work well. I have made a couple of battery holders along the lines of the IKEA holder. The batteries are “Panasonic Protected NCR18650B 3400mAh Li-Ion 18650 Button Top” batteries. I found LIionWholesale has a good price for them. The battery holder pictures weighs 2.6Oz. and a set of 4 batteries weigh 6.27 Oz. Should you use 3 batteries or 4 in series?? All of the detectors will work well with 4 batteries in series. Some low power non color detectors will run almost as long on 3 in series. They will run just a little longer on 4 in series but not 30% longer. The newer color detectors that I tested will run much longer on 4 batteries in series than with 3 in series.



The mounting clips are from McMASTER-CARR part number 1171A72. Beckson also sells a similar clips in 8 different sizes. I believe the 1 inch size would work best.
The end caps are one inch “Leg Tips” from Menards. They are displayed in the same area as cane tips. To put the hole in the end use a ALL or ICE PICK to punch a hole and put a washer on both sides of the LEG TIP on a 5/8 6-32 screw. The pipe is a ¾ inch plastic pipe from the electrical department at Menards and it comes in 5 foot lengths.
protected 3400mAh Battery

I also purchased one of these CHARGER.
Edit
The pipe is from the plumbing department. It is ¾ inch flexible water pipe part number 689-9881. It costs $2.89.

MP,

Thanks for posting the update on "rechargeable batteries". You are surely our resident battery expert.

Your Energizer Ultimate Lithium Battery holder that you set me up with 2 years ago is still working well with my Lowrance X-4 Fish finder.

If I want to go to the rechargeable route ... now I know how to do it. Thanks.

Wally13
That is still the lightest way to power your electronics. This rechargeable battery comes real close. For Ultimate lithium the holder + 8 batteries weigh 8.2 oz.
For this rechargeable the holder + 4 batteries weigh 8.9 oz. The rechargeable should run your detector just a little longer than the Lithium.

The plastic clips for mounting the pipe are from McMaster-Carr part number 1171A72 and cost $1.76 each.

I've got a few questions about the "Ikea" battery holder before starting to build one:
1. What's the best way to connect the battery holder to the fish locator?
2. Is a fuse recommended? If so, what size?
3. How is the bungee cord used?
4. What's the best location for mounting the battery holder in the canoe? Would it work to attach it to a thwart?