Thread: Battery question

Well, I’m not one to be fishing around the freezing point! Most likely hunting! LOL


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That is understandable

Lots of us run our ice fishing electronics on tool batteries. I had a stash of ryobi batteries so I went that route last year. Just need an adapter with pigtails (mine was $8), an adjustable DC voltage regulator ($9), and some kind of project box to keep water out. I've ran them down to 0F and had no issues. With garmin units, you dont have to use the DC regulator as they will run at 20-22V without issue. My humminbirds will not run over 18V even though they are supposed to be rated to 20V (all 18-20V tool batteries should be 20.5V charged and 17V dead). I knocked mine down to 13V with the regulator so it just outputs that until the batteries are dead. I will be using garmin this coming season, and will use a normal 12V lithium 12ah battery.

Math is pretty easy, you just take your draw and divide your battery capacity by that draw. So a 6ah battery will power a echomap 7sv (1a draw) for roughly 6 hours. That's max draw from garmin, and as you increase voltage the power draw is reduced slightly so keep that in mind.

The new 12V lithium batteries out now are pretty impressive, you can get a 12V 18AH lifepo4 battery for around $100. That'll run all your electronics for the day without issue if you aren't running massive stuff. The lithium is 5 pounds and takes up hardly any room.

I have looking into the 12v lithium batteries as well. I haven't figured out which electronics I will put on the front deck yet so I have some time

If you use the whole 24V from the trolling battery and run it thru a step down DC-DC device ..... It's POSSIBLE you would get enough isolation from the trolling motor battery to prevent interference .... but I have not tried it.

I thought about trying that, but in the end decided I wanted the electronics totally isolated from everything else and got a dedicated LiFeP04 battery just for electronics. Mine has a Bluetooth BMS and status and parameters can be adjusted from a phone.

If you have a while before you need to decide, order one direct via Alibaba and save some money ....all the LiFe batteries come from China anyway .... or make your own using individual cells if you are handy with this stuff. If you decide to try ordering direct, shoot me a PM and I will give you a forum where you can do your homework to find a reputable seller.

Originally Posted by BobB

If you use the whole 24V from the trolling battery and run it thru a step down DC-DC device ..... It's POSSIBLE you would get enough isolation from the trolling motor battery to prevent interference .... but I have not tried it.

I thought about trying that, but in the end decided I wanted the electronics totally isolated from everything else and got a dedicated LiFeP04 battery just for electronics. Mine has a Bluetooth BMS and status and parameters can be adjusted from a phone.

If you have a while before you need to decide, order one direct via Alibaba and save some money ....all the LiFe batteries come from China anyway .... or make your own using individual cells if you are handy with this stuff. If you decide to try ordering direct, shoot me a PM and I will give you a forum where you can do your homework to find a reputable seller.

The more I think about the voltage regulator. The more it seems like a possible fail point. I do realize that it would not leave you stranded yet I get very few days a month to get on the water. Having your electronics crap out on you would put a damper on the day. I work with robotics and industrial automation. Electronics crapping out at the worst possible time keeps me employed well that and operators that find the right pushbutton combinations to lock up the controls system. Buying the cells and building your own battery would be a good way to go.

Originally Posted by DockShootinJack

The more I think about the voltage regulator. The more it seems like a possible fail point. I do realize that it would not leave you stranded yet I get very few days a month to get on the water. Having your electronics crap out on you would put a damper on the day. I work with robotics and industrial automation. Electronics crapping out at the worst possible time keeps me employed well that and operators that find the right pushbutton combinations to lock up the controls system. Buying the cells and building your own battery would be a good way to go.

One of my boats is a Key West 1720 which has the battery compartment in the stern for both my batteries.
The factory prewired for the bow trolling motor, but there is no good way to get a wire up there for a seperate fish finder.
There is an anchor compartment however which i dont really need for fresh water fishing.
So i bought an ammo box and installed a small gel cell battery in that.
I also installed a small charging unit in there.
I only use a small basic fish finder unit up there which does have down imaging.
I can run that unit for 2 full days without recharging.
I can also remove the whole setup by just removing the ammo box and unpluging the wires.
There are some holes in the box sides for feeding the wires, but i drilled a small one in the bottom also for drainage if necessary.

I used a small gel battery to power the electronics in the kayak. It worked great for the fish finder I had then