Helix 7 power

I just ordered a Helix 7 CHIRP GPS MSI G3 and want to power it with M18 batteries. I can’t find the gauge of wire used for the power cable anywhere on the Humminbird website, or anywhere else. Can you guys check your Helix power cables and let me know what size wire it is? I would like to get all the connectors, parts and shrink tubing ahead of time so I can have power for it when it shows up.
Humminbird stats show that the unit can run on 10-20V so I was going to run it from a battery without a regulator or switch, but I’d feel better with an in-line fuse between the battery and head unit – what amp fuse would be safe? (I’m electrically challenged)
If anyone has recommendations on how to set it up, I am certainly open to ideas. I was planning to pick up a Vexilar Pro Pack to mount it on, and as I read in another thread, I should pick up some washers for mounting. I ordered the 1521 Transducer as well.
Thanks for all the help.

mojo wrote:

Can you guys check your Helix power cables and let me know what size wire it is?

but I’d feel better with an in-line fuse between the battery and head unit – what amp fuse would be safe?

I would use a 2amp fuse.

Hbird power cables are less than 12guage, likely 14?, most m18 power adapters I’ve seen are 12guage, so you’re looking at butt splicing 12ga to something lesser, then whatever the fuse holder is, likely also 12ga.

Here is the link to the Helix 7 manual. Says to use a 3amp fuse. I do not see it list 10-20V supply. It does mention the supply should be 12VDC. Also has some wire gauge sizes based off extension length. Good luck

https://humminbird.johnsonoutdoors.com/sites/johnsonoutdoors-store/files/assets/misc/HU/H/HUM_productmanual_IG_HELIX_5-7_532312/HUM_productmanual_IG_HELIX_5-7_532312.pdf?_ga=2.196946021.854743942.1579714766-1840579065.1578077582

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At the bottom of the manual in the specifications section I found the power input listed as 10-20 volts DC. There are a few threads I saw previously where others ran without a regulator. I only recall the guy who did it with his Garmin using 20 volt DeWalt batteries, and he was assured by Garmin that it was okay.
I didn’t notice that section of the manual that listed the 3 amp fuse, thanks.

Yes, my adapters are 12 ga wire, so I’ll go from that to the 3 amp fuse and then to the factory power cord.
If anyone knows the exact wire size of the power cord, that would be helpful.
Thanks again everyone, you guys always have the answers.