Low voltage?

[ReefOctopus]

Greetings,

I recently upgraded my cranking battery to a group 31 X2.

I have mega 360/ helix 12 and 2 x garmin 9's connected to it. I have a dedicated 12 gauge wire supplying power to a fuse block. I am getting a strange voltage readings from my units. The garmin is reading as low as 10.9 after 3 hours. The humminbird was at 11.5.

Any thoughts?

No issue cranking motor.

[jimsch]

I would think a 8 or even 6 ga. wire from the battery to block would be the way to solve that. 12 ga seems too small.
You could run a larger jumper wire as a test to see if that solves your problem.

[PJ-Rohlf]

Need bigger wire to the fuse block. and probably 10ga from fuse block to unit to help with voltage drop

[ReefOctopus]

I would think a 8 or even 6 ga. wire from the battery to block would be the way to solve that. 12 ga seems too small.
You could run a larger jumper wire as a test to see if that solves your problem.

From what I gathered, 10-12 gauge wire seems pretty standard for 2 units and the 360.

[ReefOctopus]

From what I gathered, 10-12 gauge wire seems pretty standard for 2 units and the 360.

Correction, I used 10 gauge to the block

[joe3buck3]

I have a Helix15 with Mega360 connected to a Minn Kota iPilot TM. I had a similar low voltage issue at the bow(10.7v) but I was running off the existing boat wiring. I ran a direct 10ga wire from the battery to the bow and now everything is fine. I ran a 12ga test line but was not happy with the voltage drop so opted for the 10ga.

[PJ-Rohlf]

10 ga on a 30' run (have to count positive and negative wire) with your setup is just enough.. seeing that you have wires after the fuse block to the units I would vote for 8ga to fuse block and 10 ga after that to ensure you don't have voltage drop issues.

https://www.wirebarn.com/Wire-Calculator-_ep_41.html

[Gsmith223]

Thats a lot of voltage loss. I would look else where, check the fuse block for loose connections. Also check all of your crimps. 10 awg tinned marine wire is the way to go. I had to make 2 runs though. One at the console and another straight to the bow.

[DewRonInc]

I am in process of fixing same issue. I got a blue sea fuse panel, ancor marine 6/2 wire to it, should fix all my issues.

[ReefOctopus]

Thanks all, I will check all connections first.

Thanks

[RockNBass]

I have a Helix15 with Mega360 connected to a Minn Kota iPilot TM. I had a similar low voltage issue at the bow(10.7v) but I was running off the existing boat wiring. I ran a direct 10ga wire from the battery to the bow and now everything is fine. I ran a 12ga test line but was not happy with the voltage drop so opted for the 10ga.

I've been thinking of going this route with a direct wire. How are you opting to fuse the direct lines if not using a fuse block and are you using step-down connectors to connect to the units' smaller gauge power cable? Thank you.

[JR19]

Some will say its overkill and wasted money and I respect their opinion but my opinion is to best resolve low voltage on multiple units that have high power demand is using a battery with high reserve capacity and a dedicated wire harness with 10 AWG. This gives you the most efficient route to supply the demand todays newer electronics require. Buying a new battery will mask the problem but low voltage it will soon show its ugly face once the battery is a little used. Running new wire to the fuse block can resolve the issue pending on how much load demand you have running through the fuse block. If you have things like shallow water anchors, black lights, radio or any thing other than electronics running through the fuse block the power demand gets higher thus your wire should get bigger in physical size. You can run them through a fuse block but I am a fan of a dedicated wire harness that way they are not sharing power with other devices and wire harnesses made for boat electronics are made with appropriate size AWG wire...again what I suggest may be over kill and may cost more but I can honestly say this...I got 99 problems and voltage drop ain't one.

[Slicefixer]

Some will say its overkill and wasted money and I respect their opinion but my opinion is to best resolve low voltage on multiple units that have high power demand is using a battery with high reserve capacity and a dedicated wire harness with 10 AWG. This gives you the most efficient route to supply the demand todays newer electronics require. Buying a new battery will mask the problem but low voltage it will soon show its ugly face once the battery is a little used. Running new wire to the fuse block can resolve the issue pending on how much load demand you have running through the fuse block. If you have things like shallow water anchors, black lights, radio or any thing other than electronics running through the fuse block the power demand gets higher thus your wire should get bigger in physical size. You can run them through a fuse block but I am a fan of a dedicated wire harness that way they are not sharing power with other devices and wire harnesses made for boat electronics are made with appropriate size AWG wire...again what I suggest may be over kill and may cost more but I can honestly say this...I got 99 problems and voltage drop ain't one.

Just wired/rewired 25 circuits and I TOTALLY agree. I'm not sure you can overkill when it comes to wiring, at least if you want to avoid shorts, blown fuses, tripped breakers, etc. Best case you chase gremlins and have to redo it, worst case you're fighting an onboard fire or burn down your garage. I soldered all connections, double shrink wrapped, heavier wire, and have a dedicated battery for all electronics....it's worth the extra #'s IMOP.

[billnorman1]

10 ga on a 30' run (have to count positive and negative wire) with your setup is just enough.. seeing that you have wires after the fuse block to the units I would vote for 8ga to fuse block and 10 ga after that to ensure you don't have voltage drop issues.

https://www.wirebarn.com/Wire-Calculator-_ep_41.html

Remember, you need equal size conductors both positive and negative.

[BroWhoop]

12 gauge is 5 amps at 30' 12 vdc. 10 ga.= 10amps, 15 amps = 8 ga

[PJ-Rohlf]

12 gauge is 5 amps at 30' 12 vdc. 10 ga.= 10amps, 15 amps = 8 ga

with electronics it isn't really about the amperage...its the 2% voltage drop rating. The less voltage drop the better.

[BroWhoop]

Exactly, smaller wire with too much current (amps) you have voltage drop. Size the wire to the amps/volts you need!