which battery for electronics

Started by scfisher, May 19, 2017, 12:01:51 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

scfisher

I have a cranking battery and a trolling motor battery.  When I got the boat only the trolling motor and the battery charger leads were connected to the trolling motor battery.  I purchased a new Garmin fish finder and it wouldn't stay on.  Every time I started the motor, shut off the motor, put the motor in or out of gear and sometimes at totally random times, the unit would shut off.  I thought there might be something wrong with it until I hooked it up to the trolling motor battery.  It hasn't given me one bit of trouble since.  However, I read online in a few places that you shouldn't power your electronics from this battery.  The only reason I can find for this is because you could experience some interference when the trolling motor is in use.  I haven't experienced this. 

My question is, is it ok to leave things wired the way they are or am I risking damage to my new fish finder?

I guess a part b to this question is does it sound like something may be wrong with my cranking circuit?  I have one of those optima blue tops but it's dated 2010.  It seems to hold a charge well so I don't want to replace it yet.  However, I just had to replace my starter.  Do these symptoms point to bigger issues to anyone?  Perhaps a bad battery lead to the starter failure and is causing voltage drops which shuts off the garmin?  The starter I took out was dated 1996(my boat is a 1997).

oldjim

What size is your motor? You can look in motor manual, look on line if you do not have manual to determine size of cranking battery. It may be your battery is not big enought for your motor.
It won't miss up your FF by using TM battery. The TM battery should be a deepcycle battery and cranking battery should be a "cranking battery."
You should be able to get FF to show low voltage on display.
If cranking battery voltage is dipping to low when it is used the FF will shut down to protect its self from low voltage.

Oldjim

ring fry

If you aren't getting any interference then it shouldn't be a problem.  Sounds like your cranking battery might be about due for replacement though.

SE Kansas grass grower
GO JAYHAWKS
2008 NCAA Basketball Champions

Princeton_Man

Quote from: ring fry on May 20, 2017, 07:31:13 AM
If you aren't getting any interference then it shouldn't be a problem.  Sounds like your cranking battery might be about due for replacement though.

SE Kansas grass grower

I agree. The Garmin unit will turn itself off when the voltage drops to around 10.5 - 11 volts.
Stratos 285 XL Pro 150 Evinrude ETEC

Dobyns Rods - LSCR Club

scfisher

Thanks for the replies.  Makes me feel a little better.  The motor is a 120.  The battery is a D34M-950 blue top.  I took it out this weekend for the first time with the new starter.  It always used to slowly chug before finally firing up.  Chug.....chug......chug chug.....chug vroom.  Anyway, now the starter spins the motor like a top.  Much less embarrassing while unloading the boat at the ramp.  All along I thought the battery was toast.  I'm not saying the battery is perfect but for now I'm not complaining. 

rebranger

Your battery is going bad,  replace it, put your ff to the tm bats on its own line / circuit

Sent from my VS835 using Tapatalk

Ed Hood
5651 Flower Lake Rd.
Dundee, MS 38626 256-883-8615 [Please enable JavaScript to see this content]