two batteries in parallel

[eyedoctor]

I do a lot drifting while jigging or bottom bouncing rigs for walleye. My lowrance gen 3 draws quite a bit of volts and will start to flicker and get fuzzy after about a half hour of drifting and if I'm using my live well that only makes it worse. So I'm thinking of hooking up two batteries in parallel. what do you guys think will it solve my problem.

[Andre wallyandre]

I'm running 1 Simrad GO 7 , 1 Simrad EVO 7", 1 HDS LIVE 12" and another 9" with a autopilot on 2 AGM 31 and 27 ; at 1st I had only 1 31 and by the end of the day it wasn't enough but adding a 2nd battery cure all the problem

[Yankee Troller]

I'd check wiring. I can run 2 10" HELIX's and my two livewell pumps for 6-8hrs without any issues while drifting. Of course I'm bouncing around on the big engine looking for better drifts, so that helps put a little something back. One unit shouldn't put that much strain on a battery that quick. I'd also look at putting in a bigger battery. On my Lund I run a 27 series Interstate cranking.

[justtracytrolling]

2 batteries isn't quite enough for me, but I make it work.  I have 2 gen 3 12s and I can't run a third 12, which I have, without going to a bigger motor, bigger batteries, a third battery, or a lithium ion battery.  I don't leave the dock without a charged jump box and that piece of mind makes it stress free to use everything.  I am planning on going to lithium ion batteries this season so I don't have to be on the dock charging all 5 batteries near as many hours and I can finally have all of my electronics on the boat and maybe even add a few more things.

[cny_mike]

Unless the batteries are exact matches internally, they will eventually draw each other down. Putting them in parallel provides a path for current to flow between them, and it will, slowly draining both.

[Rookie Fisherman]

On 12/5/2020 at 8:01 PM, eyedoctor said:

My lowrance gen 3 draws quite a bit of volts and will start to flicker and get fuzzy after about a half hour of drifting 

 

The draw is measured in amps. Depending on the size of your graph average draw should only be 1-2 amps per hour.

If you are only getting ½ hr then there is a good chance your battery maybe the issue, or possibly some other underlying problem.

 

[John E Powell]

You have a problem. Start diagnosing the problem by taking your battery in to have it tested. If this checks out, you may have a wiring problem or short, a unrelated malfunctioning onboard device, or a charging problem with an auxiliary charger or the boat’s main power.

 

If you do go the two battery route and plan on a simple parallel connection (without isolated charging) they should be same battery type, group size, capacity, and age.

 

 

John E Powell

John’s Custom Rods

Winner, 2016 International Custom Rod Building Challenge.