# Expert insight needed: Help me decide to rewire or small patches and improvements



## CHS_wop (11 mo ago)

I have a 2007 Mitzi 17ft with a pretty basic set up. I took some water on a few weeks ago which caused several electronic components to fail and as I've begun fixing I've dug deeper and considering a total rewire? I've replaced by 24v trolling motor, Power Pole HPU, 2 new 12v deep cycles, and trim tab HPU and want to make sure with these new parts I am set up for long term enjoyment. Located in Charleston if anyone wants to help take a look and lend some expertise too 

Summarizing my set up below

*House:* 2x 12v deep cycle in series with a 70amp breaker (in line on the positive 6awg wire) direct to a new battery tender plug. This is _not _on the battery disconnect switch and i'm measuring max 24v at the plug receptacle (again 2 new batteries and new battery tender plug)
is it okay that i'm not measuring more than 24v at the plug? also, do you think it's okay that this is an independent circuit and not connected to my battery switch or any other electronics? 

*Starting:* 1x 12v (deep cycle _not_starting battery )that is connected to a perco switch and has all of my center console accessories, engine start, + bilge pump connected to it
the negative part of the battery has 5 connections directly on it, i've bought a bus bar to simplify this. is this recommended?
i just bought a new promariner 3 bank charger, should I run one of the charging wires to the starting battery too?
My bilge is connected to a lot of other accessories, from a safety perspective shouldn't I have an independent power line for the bilge or not important? 


What I'm wrestling with is to keep this setup relatively the same, or should I rewire all of my accessories that are on the "starting" battery and put that on the house 24v circuit? Do i need to wire my 2 house batteries in line with the starting too or keep it independent? More detailed table below for reference. I appreciate any and all insight and painting with broad strokes here as I'm clearly new to all of this. 


*Components**Power Sources**Dash Components (together on one neg connection)*50HP Yamaha1x deep cycle (starting battery)Bilge PumpBilge Pump2x deep cycle (new only for TM currently)CompassStern Light_1 perco only seems to have starting bat on it)_RadioNav LightGarminSmall LED onboard lightsEngine ignition + tachometerCompassAll lightsMarine RadioSwitchboard (3 lights, bilge)GarminPower PoleTrim TabsPromariner 3 bank charger80lb terrova


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## permitchaser (Aug 26, 2013)

I’m doing a re-wire this winter. I think you bilge should be on your TM batteries, if your Bilge runs down your starting battery your toast. My 24v system has a new shut off switch. Go with your idea of separate buses with fuses. You shouldn’t have to charge your crank battery if you use your boat it will charge it. If you have to charge it, get a new battery
I’m not sure what you mean about your bilge connected to other things. It should just have its own spot on the buse 
Also if you use your 24v batteries your bilge can only be on 12v
If things broke from a little water you need to re-wire with shrink connections


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## CHS_wop (11 mo ago)

thanks. so would you recommend downgrading from a 3 bank charger and just get a 2 bank charger for the TM batteries only? 

also, the guy i bought the boat from had a deep cycle as the starting battery. do i need to get a new one in your opinion?


permitchaser said:


> I’m doing a re-wire this winter. I think you bilge should be on your TM batteries, if your Bilge runs down your starting battery your toast. My 24v system has a new shut off switch. Go with your idea of separate buses with fuses. You shouldn’t have to charge your crank battery if you use your boat it will charge it. If you have to charge it, get a new battery
> I’m not sure what you mean about your bilge connected to other things. It should just have its own spot on the buse
> Also if you use your 24v batteries your bilge can only be on 12v
> If things broke from a little water you need to re-wire with shrink connections


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## GitFishin (May 10, 2019)

First thing I would do is go to New Wire Marine's website and get their wiring guide. I'd read it all the way through and decide if I wanted to make any changes to the wiring on my boat. There's plenty of info in there about how to configure your batteries. Finally I think the guys who wire boats say rewire every 10 years. That might be aggressive especially if you have maintained things properly and had no major incidents. My guess would be that after 15 years and at least one significant event it's probably time in your case.

My personal opinion and worth every penny you paid for it


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## permitchaser (Aug 26, 2013)

CHS_wop said:


> thanks. so would you recommend downgrading from a 3 bank charger and just get a 2 bank charger for the TM batteries only?
> 
> also, the guy i bought the boat from had a deep cycle as the starting battery. do i need to get a new one in your opinion?


Do you know how old the battery is. If it’s more than 2-3 years replace with a 1,000 cranker 
I have a Minkota 2 bank charger on my boat and a separate charger in my garage just in case


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