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Boundary Waters Quetico Forum :: Fishing Forum :: Rechargeable lightweight power source
 
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daverr
04/11/2018 08:36AM
 
I see that my understanding of batteries is pretty elementary. I've use all sorts of AA batteries for my Eagle Cuda fishfinder. Maybe I should ask a more general question - for a standard weeklong trip with 5 hours fishfinder use per day (35 hours total), how many 18650 batteries (protected and with between 3000 and 3300 mah) should I use?
 
MagicPaddler
04/11/2018 09:37AM
 
daverr: "I see that my understanding of batteries is pretty elementary. I've use all sorts of AA batteries for my Eagle Cuda fishfinder. Maybe I should ask a more general question - for a standard weeklong trip with 5 hours fishfinder use per day (35 hours total), how many 18650 batteries (protected and with between 3000 and 3300 mah) should I use?"
Well that depends on what fish finder. Assume you are buying today so you can’t get a gray scale unit. Say you buy a Lowrance Hook-4x. That detector draws about 220 mA. For 35 hours of operations you would need 7700mAh of power. It would take 2&1/2 sets of batteries to power that detector for 35 hours. That would be 3 sets of 4 batteries each or 12 batteries.
https://www.imrbatteries.com/panasonic-ncr18650b-18650-3350mah-protected-button-top-battery/
At $6.50 each there is a initial investment. You also need a charger which will cost about $15. I have been using my batteries for 3 years now and they have met specifications.
Making a comparison to AA batteries. Ikea AA are one of the best AA batteries on the market and they are one of the least expensive. They will supply about 2000mAh at 220mA and they cost $1. Each. To use all of the energy out of an alkaline cell before the voltage drops too low for most detectors 10 cells are required in series. So to run that detector for 35 hours on Ikea AA would require 3.9 set of 10 batteries. That would be 4 sets of 10 or 40 batteries or $40. You can see why people want the older detectors that draw less than ½ the current of the new ones.

 
daverr
04/11/2018 11:28AM
 
Just checked my owner's manual - my black/white fishfinder draws 110 ma power (unless its back light is on, which is rare). How would that change your calculations?


And, are these the IKEA batteries you are talking about? IKEA batteries
 
AmarilloJim
04/11/2018 11:12AM
 
Colder air temps will effect battery life as well.
 
daverr
04/11/2018 11:37AM
 
Actually, I bet these are the IKEA batteries: IKEA batteries
 
MagicPaddler
04/11/2018 01:10PM
 
These are the Ikea batteries I was talking about. They are not rechargeable.
https://www.ebay.com/i/301366981334?chn=ps&dispItem=1
I do not have any test data on the batteries you linked look interesting though. I read that they are Ni-mh which are about 1.2 volts so most detectors would run better on 10 of them in series.
If you have a detector that draws 110mA it should get 2 times long of run time on a set of batteries than the one in my post above or you will need ½ as many batteries.

 
daverr
04/10/2018 10:38AM
 
I've been strongly considering redoing my AA battery pack setup with rechargeable 18650s. Thank you for posting about this. Would you post a picture of the final setup (with the batteries all wired up in the peanut butter jar)? I am a bit imaginatively challenged.
 
AmarilloJim
04/10/2018 11:01AM
 
Do these recharge well with a solar charger? Will they last for years? I would only use them on Q trips 2x/year.
 
MagicPaddler
04/10/2018 12:29PM
 
Daverr

The 2 holders are taped together with white tape.
Amarillojim
These batteries are advertised as being good for 1000 recharge cycles. They are what is in some of the Tesla cars. Never used a solar charger and unless you are going on a month + long trip it is less weight and hassle to take extra batteries.


These batteries should be charged in a charger designed for Li-ion batteries.
 
daverr
04/10/2018 01:50PM
 
Thank you, MagicPaddler. This is very helpful. In 18650s, what is the equivalent of an 8 pack of AAs?
 
MagicPaddler
04/10/2018 04:18PM
 
daverr: "Thank you, MagicPaddler. This is very helpful. In 18650s, what is the equivalent of an 8 pack of AAs? "
Not all AA are created equal. Alkaline AA vary brand to brand from 224 mAh to 2328 mAh then there is Energizer ultimate Lithium AA which have 3312 mAh. The above mAh values are measured values from a source I trust. So what brand of AA do you use are you using Alkaline or Lithium and 8 or 10 in series?
The same can be said for 18650 batteries. I would recommend one of the battery models that have between 3000 and 3400 mAh that I can get measured values for.

 
MagicPaddler
04/13/2018 01:19PM
 
AmarilloJim: "Are most rechargeable AA's 1.2V? Every alkaline AA I have used seem to be 1.5V."


It depends on the chemistry. Most of the AA and AAA rechargeable today are NiMH and under light load they start off at 1.4 Volts and soon droop to around 1.2 volts. They stay at 1.2 Volts until most of their energy is used.
Alkaline batteries start off at 1.6 volts more linearly than NiMH but still faster at the beginning. When they get a little below 1 volt most of the energy is used out of them.
The Energizer Ultimate Lithium start off at 1.7 volts and drop very rapidly to 1.5 volts and when they get below 1.3 volts most of their energy is gone.
The LiIon start off at 4.2 Volts and when they get below 3 volts they are out of energy.
All approximate numbers.

 
AmarilloJim
04/13/2018 11:35AM
 
Are most rechargeable AA's 1.2V? Every alkaline AA I have used seem to be 1.5V.
 
MagicPaddler
04/15/2018 07:57PM
 
Another possible battery for powering fish detector is a 16AH Battery 2.84 LB $54.66
You must never overcharge or over discharge these batteries or they will be destroyed or catch fire. If you are the type of person that can shut off your detector when you hear and alarm then here is an ALARM.
This alarm will plug directly into a 5 wire cable coming out of the battery.
By using a CHARGE CABLE a adapter can be made to be able to plug and unplug the battery from the detector.
Charge Cable XT90 to 4mm Banana 2 at $4.19 each
These batteries must be charged with a charger that will monitor and balance each cell. Here is a charger that will charge this type of battery and it will run off of 120V or 12V. Will it run off of a 12 V solar panel; I don’t know. Charger 12V or 120V input $29.14
 
arnesr
04/16/2018 09:47AM
 
This is the battery I have been using the last few years. It's a LiFePO4 battery and though it's more expensive initially I'm hoping it will last many years. It's the same size as my Vexilar battery I use for Ice fishing, but much lighter. It requires it's own smart charger and cannot be charged safely with a regular 12V charger. The battery is sealed, but I still like to keep it in a waterproof container as extra protection. I had been using it in a larger Lock and Lock brand container, but I have found that the battery fits perfectly in a Lock and Lock HPL820 designed for cracker storage, so I will be converting to that this year.
LiFePO4 Battery



 
MagicPaddler
04/16/2018 10:41AM
 
Arnesr The battery you suggested is also one of the newer battery technologies. In general that chemistry is just a shade heavier than the Lipo chemistry batteries for the same energy storage. Usually they are stated to have a life of 2000 recharges while the Lipo has a life of 1000 recharges. Good to hear of your success.
 
MagicPaddler
04/09/2018 04:21PM
 
The go to battery in camera, phones, computers and cars are Li-ion. I believe the most used and form of Li-ion battery is the 18650. There are many reputable sources for these batteries. There are even more UNreputable sources. These batteries need protection and they can be bought with built in protection. The protected batteries are slightly longer then the unprotected ones. I have built several holders and posted for building them. They work well if your batteries get permanently mounted in the canoe. Many people don’t want that type of holder. Many people want their batteries in a bag to be easily taken out of the canoe. A nice example in under the “The sweetest canoe depthfinder setup ever” thread about 1/3 of the way down the page Amarillojim shows off his setup on a removable yoke. So I looked at how to make a light weight battery pack that would fit in a pack like Amarillojim’s bag.
I have purchased some 18650 holders that will hold 2 batteries. The one with the springs in the end are just long enough for the protected cells. Do Not use different types of batteries in the same bank. I did that just to show either one would fit the holder. If you do a search on eBay for “ aa/aaa/18650 battery holder “ you can find them. I paid $4.59 + $2.09 shipping for 5 of them. Drill 2 holds in the lid about 1&1/2 inches apart big enough for 6-32 screws. Hook the 2 holders in series and connect the other 2 wires to the screws with ring terminals. Put the screws through the holes and put nuts on them and tighten them down. Add a second set of nuts placing the fish detector wires between the nuts tighten them. Put batteries in the holders and put the holders in the jar and screw the jar on the lid.
Any 18650 battery should fit this holder so which one to buy. The best battery makers can only mas produce 18650 batteries that have up to 3500mAh and they will cost you over $6 for ones with the protection circuit added. So if they are advertised as more than 3500mAh and they are less than $6 for the protected ones they are not an honest dealer. I have purchased batteries form https://liionwholesale.com/collections/batteries/protected and gotten good service. I see my favorite the Panasonic is out of stock so my second choice would be the Protected LG F1L 3350mAh for $6.50 each.