Humminbird 998 displays low voltage

[Fishin_Impossible]

After a couple hours on the water, my depth finder displays a low voltage message when starting the motor. I checked the voltage at the battery, (12.7) and at the depth finder end of the power wire (12.5). Load test on the 2 year old battery passed, the motor is an ‘02 - 2 stroke Yamaha 150, battery is an interstate M24.

The depth finder power runs through the Master Switch. My first thought is to wire directly to the battery, (remove from the master switch) and replace with a heavier gauge wire. The manual says the power wire can be lengthened using 18 gauge wire, but some of the posts I’ve read say to update to a heavier stranded marine wire, (like 10 to 12 gauge). Does that seem like too heavy of a power wire?

Other thought is will an M27 battery take care of the problem?

I have the usual stereo, live/bait wells a second finder on the bow, and of course interior and nav lights etc.

The boat is setup for running 2 electric cannon downriggers, however they don’t get used often (and weren’t when I got the low voltage warning) So would an AGM battery be a better choice?

I’m definitely not an electrical expert. I know very little about it, so any advice would be appreciated. Thanks

[rnvinc]

The cost differential in wire size is minimal ...

Using 10gauge direct from the battery (with a fuse of course) is good practice ...

Rickie

[wallybagger]

Go into setting and change low voltage alarm to 12.0 volts and see if that gets rid of the alarm. Worked on my 898.

[Fishin_Impossible]

Thanks, I did move the warning down to 11 or 11.5 while it was giving me the errors, I’ll try running a new fused 10 gauge power wire from the battery, would it be possible that the master switch could be some of this trouble? Or would running it through the switch not make a difference? Thanks

[Snowking]

The amp reading on my Lowrance screen was always lower then actual reading. I does not hurt to run a separate power wire for the graph. It also sometimes helps for interference issues. With the amount of amps even a 998 can draw. Plus if you have livewell running. It never is a bad idea to go with minimum size 27 batterys. Just make sure any 27 battery has higher specs then what you are running now. As far as if you are running a high end 24 battery and switch to a cheap 27 battery. Size 31s are even better. Since you are not running two 12 inch graphs. The 27 should be enough.

[DW]

Dont waste your effort on new wiring. Instead buy the biggest battery you can buy with the highest CCA and RC rating.

[Fishin_Impossible]

Thanks snow king, chances are I’ll run a new wire, and move to a bigger battery.

[bbheli]

Originally Posted by Fishin_Impossible

Thanks, I did move the warning down to 11 or 11.5 while it was giving me the errors, I’ll try running a new fused 10 gauge power wire from the battery, would it be possible that the master switch could be some of this trouble? Or would running it through the switch not make a difference? Thanks

Corrosion and bad connection points equal resistance which results in voltage to drop. Good heavy copper terminal ring. If you don't have a tester try connecting it right to your battery terminals for a second if not to much trouble and see what it reads.