Boundary Waters Quetico Forum :: Fishing Forum :: Rechargeable lightweight power source
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daverr |
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MagicPaddler |
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. |
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daverr |
And, are these the IKEA batteries you are talking about? IKEA batteries |
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AmarilloJim |
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daverr |
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MagicPaddler |
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. |
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daverr |
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AmarilloJim |
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MagicPaddler |
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. |
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daverr |
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MagicPaddler |
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. |
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MagicPaddler |
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. |
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AmarilloJim |
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MagicPaddler |
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 |
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arnesr |
LiFePO4 Battery |
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MagicPaddler |
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MagicPaddler |
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. |