Voltage to Graphs Adequate Enough or Is problem Elsewhere?

[BassCatKev]

My 2 bow Helix 10s indicate 12.1 volts on the digital readouts on the graph. My 2 dash helix 10s read 12.3 and 12.4. This is in the garage with only graphs (no livewells, lights etc) running.
I just fully charged my batteries.
31 series Pro Guide AGM battery (225 boat hours 1 year old), vattery tested 13.0 under no load.

Are those voltage readings ok? I'm getting some interference with my 360 and trying to eliminate possibility of it being from low battery. I also had a Suzuki alarm go off that may have been related to a low battery but have posted about that in Suzuki forum.

Battery only one year old but wonder if hours and hard use (previously owned by a pro) have taken it's toll. I was hoping for a few more seasons out of battery of that caliber (IF that's the issue).

All opinions/suggestions welcome. Thank you as always

[skid00skid00]

You need to wait 24 hours after a charge, before you measure voltage (surface charge). Google AGM voltage for an acceptable voltage. If that battery was left at a low charge, it could have been degraded. Solar makes an affordable battery tester, or get a hydrometer to check cells (if AGM has caps?).


Interference isn't caused by low voltage. Clean all cable ends for low resistance.

[CatFan]

You are good.

[Bob B]

The voltage to your units are OK at full charge, but since you are dropping .9 V thru the wiring to the bow unit, you could have issues as the battery begins to discharge. .9V drop thru the wiring is not a good thing. I would suspect that just letting the battery sit for 24 hours and re-checking will show the voltage below 12V at the bow.
I never want to see the voltage on my units drop below 12V ... when not cranking the motor.

[BassCatKev]

I did do that observation just after unplugging my charger. I did not wait 24 hours. So guess it could only be worse. Are there any AGM starter battery owners out there that know how to tell if it's time for it to be replaced other than if it doesn't test 13 volts (which mine does that)? I don't see any caps on the battery. Just the 2 main terminals.

[Bob B]

It looks like you are dropping too much voltage in the wiring to the bow unit. That would be a wiring, not a battery problem.