Topic: 898c SI voltage reading (low)

[snopro67]

my unit seems to read about .4 VDC lower than the actual voltage. Anyone else have this issue? This almost caused me to buy a new battery.

It is connected to the battery with 16 guage wire with nothing else running on it.
16' Walleye boat. I have firmware version 5.500

[stillbear]

Your unit will run on 10-20 volts.What meter gauge etc. do you go by. Run till it
quits working. Gary

[snopro67]

Gary,
I realize the unit will stay running. I use this voltage reading to gauge my battery "stage of charge"
A battery reading 12.3 volts with say just the running lights on would indicate a good battery charge. But my unit would read 11.9 volts indicating a possible problem.

[stillbear]

Snop67 That reading difference you are talking about is a reading with and without resistance
your unit has resistance and is showing a different voltage. Which is normal. I check my
battery with a hydrometer then if the cells are all pretty equal I can load test it if I want.

[snopro67]

Gary,
All I can say is this "resistance" effect doesn't seem to affect my $200.00 Humminbird 565 near to the same extent. I understand I won't have the exact reading I do at the battery because the wire has resistance in it, the farther from the wire the more resistance. But a .4 to .5 VDC error seems excessive. Especially when I can check the voltage at the fuseholder which is soldered at the end of the Humminbird wiring harness. I get a .35 VDC error there. I emailed Humminbird to see what they say

[Del]

Well, your $200 565 has a smaller screen and a differten transducer, the power consumption should be less than on your 989. Higher power consumption would result in higher resitance and a lower voltage level. If i'm putting on full nav-lights on my boat my main battery's voltage drops from 12,6 to 12,1. I would assume you to check your voltage level with a voltmeter, when your 989 is powered on and off to check the difference.

Greetings,
Del

[stillbear]

my unit seems to read about .4 VDC lower than the actual voltage. Anyone else have this issue? This almost caused me to buy a new battery.

It is connected to the battery with 16 gauge wire with nothing else running on it.
16' Walleye boat. I have firmware version 5.500

Del checking  or replacing a battery because of what a voltmeter says is proably the
worst thing you could do.If your unit reads around 12 volts give or take a few points when
your trolling and around 13 volts or more when you start your big motor you are good to go.

[edwardpic]

I have found on my boat even the digital battery gauge is off just a little....I use a battery tester I have here at my shop for a true battery test....I have a gauge cluster that all 3 of my batteries have their own gauge, but, at the same time I have a 20 watt solar panel attached to my T-top and charges the battery used for livewell-electronics and radios all the time, it has a charging regulator wired in between....

[Del]

Del checking  or replacing a battery because of what a voltmeter says is proably the
worst thing you could do.If your unit reads around 12 volts give or take a few points when
your trolling and around 13 volts or more when you start your big motor you are good to go.

That's not been me!   
Theres really no reason to worry about lower voltage readings while the unit is powered on. I tested just the same with my 1197 and i had a 0.4 drop, too.


edit; no problem stillbear 

[stillbear]

Sorry Del I meant snopro 67