I wanted to share this adapter I used to rig up my Garmin Striker 4 to run off of 20V Dewalt batteries. I went this route because I have plenty of these batteries, they are fairly light and small, and I should get ~20hrs run time per 5ah battery.

I set my voltage alarm at 15.5V, so each cell should have plenty of leftover voltage to prevent damage to the battery.

I took apart the battery adapter and used fender washers on the inside to provide some extra support for the FF unit. The Garmin mount then gets bolted to the adapter and I cut and soldered the Garmin power cable to the adapter leads.

Overall, pretty easy build!

https://www.amazon.com/dp/B08JLYPY4F?psc=1&ref=ppx_yo2ov_dt_b_product_details

I have read about folks who did this, no haven’t seen a mount directly to the battery like this. Very clean! Sure beats a vexilar battery in a separate box.

Very slick setup! Should serve you well. Well done.

I don't know anything about electronics or electricity. How does a 20v battery not harm a 12v device? I want to do this and I found milwaukee adapters but do I need some kind of regulator? And also, what is the voltage alarm you set? Thanks...I'm really dense about this kind of thing.

Rockriver: "...How does a 20v battery not harm a 12v device?....I'm really dense about this kind of thing. "

Not too dense to ask a very good question!

12v is the recommended minimum. That unit operates on a range of 10-20v if you look at the specs. You would want to check the user manual for the acceptable range of whatever unit you intend to use.

I believe PRSGuitars is setting up a voltage alarm on his fish finder, so he knows when to shut it off so that he does not damage the battery. If you drain a Lithium battery too far it will damage it and it will not charge up again to it's maximum capacity. I am kind of surprised that Dewalt doesn't put over discharge protection circuitry in the their batteries. I use Ryobi batteries and they do have over discharge protection built in.

Be careful too when relying on nominal voltages, as actual voltages can be a bit higher. For example my 18V Ryobi batteries when fully charged are 20.x volts when measured. I would put a multimeter on the terminals of you freshly charged Dewalt battery and see exactly what kind of voltages you are dealing with. I would guess it is just a naming convention as both brands use the same types of cells internally, so Ryobi 18V=Dewalt 20V. Regardless, you are at the top end of the voltage range for your unit. I would speculate that running your unit at the higher voltage could decrease efficiency and generate more heat, thus reducing the life of the unit.

I'll check a fresh battery tomorrow to make sure what it is. The milwaukee adapter I found is for those 12v kids trucks/jeep things. It has an on/off switch and an inline 3 amp fuse. Don't have a clue about voltage alert. I assume my milwaukee batteries have it built in.

I've rigged lights to milwaukee and ridgid batteries useing alligator clips for years. Run them down till nothing many times with no issues that I've noticed. I like the idea of streamlining everything. Wish I could shorten my transducer cable to about four feet but I've always heard it's not a good idea to splice them.

Rockriver: "I don't know anything about electronics or electricity. How does a 20v battery not harm a 12v device? I want to do this and I found milwaukee adapters but do I need some kind of regulator? And also, what is the voltage alarm you set? Thanks...I'm really dense about this kind of thing. "

Good question! Per Garmin, this unit can use 12V-20V supply voltage. I measured a couple of my 20V batteries after a full charge and they measured ~20.6V on average so I am taking a risk in running these batteries, but it is one I'm willing to accept. My background is in engineering and with any specification, we give some form of "factor of safety" to account for errors. Without knowing their actual safety factor, I could be taking a big risk or be well within tolerance.

arnesr is correct that with higher voltages, some of the components would likely run hotter than intended and this usually leads to earlier failure. To feel more confident about this risk, I took the unit apart and ran it under 12.6V for ~30min. I used a thermal camera to look for any overheating components but didn't notice anything too concerning (though this was just gut feel for what "concerning" is).

The Striker 4 lets you set a voltage alarm to help prevent draining your battery too far. I set mine somewhat conservatively to protect my batteries.

If anyone chooses to go this same route, do it at your own risk. Understand that a fully charged 20V DeWalt battery is over Garmin's input voltage specifications. You could also go with a step-down regulator to get to 12V. I chose not to go that route as there would be some parasitic draw in the regulator and don't want to risk running out of battery life up in the BW.

PRSGuitars: "

Rockriver: "I don't know anything about electronics or electricity. How does a 20v battery not harm a 12v device? I want to do this and I found milwaukee adapters but do I need some kind of regulator? And also, what is the voltage alarm you set? Thanks...I'm really dense about this kind of thing. "

Good question! Per Garmin, this unit can use 12V-20V supply voltage. I measured a couple of my 20V batteries after a full charge and they measured ~20.6V on average so I am taking a risk in running these batteries, but it is one I'm willing to accept. My background is in engineering and with any specification, we give some form of "factor of safety" to account for errors. Without knowing their actual safety factor, I could be taking a big risk or be well within tolerance.


arnesr is correct that with higher voltages, some of the components would likely run hotter than intended and this usually leads to earlier failure. To feel more confident about this risk, I took the unit apart and ran it under 12.6V for ~30min. I used a thermal camera to look for any overheating components but didn't notice anything too concerning (though this was just gut feel for what "concerning" is).


The Striker 4 lets you set a voltage alarm to help prevent draining your battery too far. I set mine somewhat conservatively to protect my batteries.


If anyone chooses to go this same route, do it at your own risk. Understand that a fully charged 20V DeWalt battery is over Garmin's input voltage specifications. You could also go with a step-down regulator to get to 12V. I chose not to go that route as there would be some parasitic draw in the regulator and don't want to risk running out of battery life up in the BW."

OK... you got the electronics down. Know anything about fishin'?

bobbernumber3: "

PRSGuitars: "

Rockriver: "I don't know anything about electronics or electricity. How does a 20v battery not harm a 12v device? I want to do this and I found milwaukee adapters but do I need some kind of regulator? And also, what is the voltage alarm you set? Thanks...I'm really dense about this kind of thing. "

Good question! Per Garmin, this unit can use 12V-20V supply voltage. I measured a couple of my 20V batteries after a full charge and they measured ~20.6V on average so I am taking a risk in running these batteries, but it is one I'm willing to accept. My background is in engineering and with any specification, we give some form of "factor of safety" to account for errors. Without knowing their actual safety factor, I could be taking a big risk or be well within tolerance.



arnesr is correct that with higher voltages, some of the components would likely run hotter than intended and this usually leads to earlier failure. To feel more confident about this risk, I took the unit apart and ran it under 12.6V for ~30min. I used a thermal camera to look for any overheating components but didn't notice anything too concerning (though this was just gut feel for what "concerning" is).



The Striker 4 lets you set a voltage alarm to help prevent draining your battery too far. I set mine somewhat conservatively to protect my batteries.



If anyone chooses to go this same route, do it at your own risk. Understand that a fully charged 20V DeWalt battery is over Garmin's input voltage specifications. You could also go with a step-down regulator to get to 12V. I chose not to go that route as there would be some parasitic draw in the regulator and don't want to risk running out of battery life up in the BW."

OK... you got the electronics down. Know anything about fishin'?"

Not enough about fishing - I'm always learning! This is actually the first year using a fish finder for me so I'm curious how it will go.

I like it alot. So much neater than my previous setup. I had to make the wires a little longer than I would've wanted to or either cut out the blade fuse. Also wish I had used a smaller connector but that one came with the adaptor. I have some loom somewhere to finish it off. Thanks for the idea PRSGuitars and everyone else for the explanations. Lol

Rockriver: " I like it alot. So much neater than my previous setup. I had to make the wires a little longer than I would've wanted to or either cut out the blade fuse. Also wish I had used a smaller connector but that one came with the adaptor. I have some loom somewhere to finish it off. Thanks for the idea PRSGuitars and everyone else for the explanations. Lol

"

Nice work, Rockriver! Makes a pretty clean package and should be easy to pack.
Out of curiosity, have you measured voltage on a fully charged Milwaukee 18V? I assume it's the same as DeWalt; 20.5V-20.6V

I had one full charged but never used during ice season. Brand new never used and it read 20.4v . I'll guess it was 2.5 months since charging. I bought a two pack. The other I used on my auger and ran it down to two bars. Charged it the other night and it read 20.2v. I checked some older batteries and they were all over the place with the highest being 20.2. The two brand new batteries were both 4ah.

I used it today for about two hours and it still showed full charge by the light bars. I have a bunch of old transducers and I think I'm gonna cut one down to about 3'. Never tried it before and I hear it's fine, it's not recommended, and don't do it. Lol. Guess I'll find out. Thanks again.

Rockriver: "I had one full charged but never used during ice season. Brand new never used and it read 20.4v . I'll guess it was 2.5 months since charging. I bought a two pack. The other I used on my auger and ran it down to two bars. Charged it the other night and it read 20.2v. I checked some older batteries and they were all over the place with the highest being 20.2. The two brand new batteries were both 4ah.


I used it today for about two hours and it still showed full charge by the light bars. I have a bunch of old transducers and I think I'm gonna cut one down to about 3'. Never tried it before and I hear it's fine, it's not recommended, and don't do it. Lol. Guess I'll find out. Thanks again."

Let us know how cutting the transducer wire goes! I would love to cut the cord shorter but wasn't 100% confident it won't mess with how the system determines depth/signal processing.

Would this run longer than using 8 AA batteries?

wannabeoutthere: "Would this run longer than using 8 AA batteries?"

Yes, these batteries would last longer than 8X AA batteries, but it all comes down to the batteries' mAh or Ah. I expect a 5Ah DeWalt battery to last up to 20hrs (5Ah/0.24A draw = 20.8hrs) and a set of 8X 3000mAh AA lithium batteries to last up to 12hrs (3Ah/.24A draw = 12.5hrs).

This math is also in a "perfect world" and doesn't take into account battery temperature/screen brightness/etc. The 0.24A draw I measured was also at 20V, so I'm not sure if the amp draw will be any different for 8X AA batteries at 12V.

wannabeoutthere: "Would this run longer than using 8 AA batteries?"

AA batteries are typically 2000-3000mAh, which is 2-3 Amp hours. The Dewalt and Milwaukee batteries are 5Ah. Using 8 batteries doesn't give you any extra capacity, it just gets you up to the 12V to run the fish finder. The battery pack would last about twice as long.

I looked up the Garmin Striker and it has a max current draw of 1.0 A and a typical current draw of 0.23 A. This means that the battery packs would last 5 hours at peak current draw and about 21 hours at the typical draw. AA batteries would be at best, 13 hours.

Keep in mind that this does not compensate for the voltage difference. Typically, higher voltage gets regulated down, which lowers the current draw on the battery. This should make the battery pack last even longer, but I do not know if that is the case here.

Thank you PRSGuitars and A1t2o.

Do you have a picture of how you mounted the depth finder to the adapter?

Forget it. I now see on my adapter that it is held together by screws. I thought it was molded plastic.

Update on the DeWalt powered Garmin 4 - Just got back from a 5-day trip and used the Garming to map most of our main fishing area for the week. My battery started out at 20.7V and ended the trip at about 18.5V. This was on 70%-80% brightness and using the fish finder for several hours a day while we fished. The only thing I didn't like is the transducer cord length, which I may shorten for our next trip. I'll keep the cord long enough for the person in the bow to use it if the transducer is in the stern.

Very slick.

Has anyone tried using a 20 volt battery on a Lowrance X4-Pro?

Specs say input needs to be 10-17 volts. My dewalt 20 volt batteries are 20.5 volt fully charged. I don't want to fry my depth finder.

jackson: "Very slick.


Has anyone tried using a 20 volt battery on a Lowrance X4-Pro?


Specs say input needs to be 10-17 volts. My dewalt 20 volt batteries are 20.5 volt fully charged. I don't want to fry my depth finder."

I would be a little nervous with this setup as you're probably stretching the limit on what that FF can handle for voltage. I would recommend using a voltage converter to drop the incoming voltage down to 12V, similar to this: https://www.amazon.com/Mellif-Converter-Inverter-Automatic-Regulator/dp/B0BSF7ZNFD?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=A14VVZW4JSF9TH

PRSGuitars: "

jackson: "Very slick.



Has anyone tried using a 20 volt battery on a Lowrance X4-Pro?



Specs say input needs to be 10-17 volts. My dewalt 20 volt batteries are 20.5 volt fully charged. I don't want to fry my depth finder."

I would be a little nervous with this setup as you're probably stretching the limit on what that FF can handle for voltage. I would recommend using a voltage converter to drop the incoming voltage down to 12V, similar to this: https://www.amazon.com/Mellif-Converter-Inverter-Automatic-Regulator/dp/B0BSF7ZNFD?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=A14VVZW4JSF9TH"

100% correct. It didn't work. The battery tests 20.5 volts without load, but the battery manual says the battery typically drops to "18 volts under load". I was optimistic this was the case for my situation and I would only be 1 volt over spec. Too bad the depth finder draw is pretty small (170 mA) and the voltage drop was negligible. The depth finder is fine but the transducer is fried. Live and learn.

jackson: "

PRSGuitars: "

jackson: "Very slick.



Has anyone tried using a 20 volt battery on a Lowrance X4-Pro?



Specs say input needs to be 10-17 volts. My dewalt 20 volt batteries are 20.5 volt fully charged. I don't want to fry my depth finder."

I would be a little nervous with this setup as you're probably stretching the limit on what that FF can handle for voltage. I would recommend using a voltage converter to drop the incoming voltage down to 12V, similar to this: https://www.amazon.com/Mellif-Converter-Inverter-Automatic-Regulator/dp/B0BSF7ZNFD?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=A14VVZW4JSF9TH"

100% correct. It didn't work. The battery tests 20.5 volts without load, but the battery manual says the battery typically drops to "18 volts under load". I was optimistic this was the case for my situation and I would only be 1 volt over spec. Too bad the depth finder draw is pretty small (170 mA) and the voltage drop was negligible. The depth finder is fine but the transducer is fried. Live and learn. "

Well silver lining is now you know with 100% certainty if it will work lol

jackson:

100% correct. It didn't work. The battery tests 20.5 volts without load, but the battery manual says the battery typically drops to "18 volts under load". I was optimistic this was the case for my situation and I would only be 1 volt over spec. Too bad the depth finder draw is pretty small (170 mA) and the voltage drop was negligible. The depth finder is fine but the transducer is fried. Live and learn. "

I assume the transducer stopped clicking? Did you try another transducer to make sure your unit is still working correctly? There are a quite a number of Lowrance/Eagle units that use the same transducer as the x-4 (HST-WSU), so you may be able to find one on marketplace or similar at a reasonable price, perhaps a whole new unit for less than the price of a brand new transducer.