whoops, left out the float switch on that diagram.
With a standard 1-2-both battery switch, with the switch in position 1 everything runs off battery 1. Switch in 2, everything runs off of 2. Both, parallels the two batteries so everything runs off of both. While you can switch to both and get a little extra juice to get the OB started should you have a low starting battery, the batteries also equalize each other. Best not to run on both unless you’re just trying to get your OB started. So if you’re on both and running your TM all day, you’re draining both batteries down. In most cases you want your starting battery isolated from your house accessories to ensure that you always have starting juice and nothing else drawing that battery down. Me personally, on a small inshore boat with a TM, I want the TM isolated because it is a large power draw. That way if I kill the TM battery it doesn’t affect anything else on the boat. It also eliminates power surges to the electronics of your TM turning on and off, as well as eliminates another chance for electrical interference with the fish finder with them running off of separate power supplies. If you pay halfway attention throughout the day, the chances of you killing a battery by running a GPS and radio (assuming you’re not running an amp) are slim compared to killing a TM battery, or both, with running the TM all day.
No CB between switch and Yamaha.
50 amp on the TM circuit.
Need to size the main wire and CB based on the total house loads you’re running off of your fuse panel.
No, you won’t lose power to your accessories. You’ll just be drawing all accessories on your boat from whichever battery you have the switch set to.
So let’s say the amp draw from all of your accessories together is 50 amps. A 55 ipilot alone has a max amp draw of 50 amps according to MK specs. That’ll be wide open. So think about the total amp draw on your house battery if you’re running TM + Simrad + stereo + baitwell, for hours at a time fishing between running the OB and having a charging current going. My 0.02 is the take the chance of having the massive amp draw of the TM off the battery bank that contains my starting battery.
My last inshore boat I ran two group 24s on a standard switch. That handles the OB and house acc. Always ran on one or the other but not both. That way if I killed one with the acc while fishing or beaching, I could switch to the other to start the OB. Switch back to charge the low one. TM battery was a group 31 by itself. No switch on it, just tripped the breaker to act as my switch on that circuit. It was dry stacked so my TM battery was removed and taken home to charge each trip.
You could use a VSR to isolate the two batteries as two separate banks, and still have charging current from the OB to both batteries.
I don’t have room to run 3 batteries…nor do I want the added weight. I need a way to use two batteries for house/OB/TM and still be safe. I don’t want to kill the OB/house battery by using the TM.
BUT…beaching and blasting stereo is not what I do. So if I had OB/house on same battery, I would not be worried about killing it running ACC.
So, thinking that, couldn’t I just isolate TM battery with CB like you said, and run one battery through switch to HOUSE, and not through switch for OB?
If you want to retain the ability to charge the TM battery with the charging current from the OB, consider a VSR system. http://www.bepmarine.com/en/715-h
If you don’t care about charging the TM battery via the OB while it’s running, then you could do a battery to a on/off switch, from that switch to the OB and CB/Fuse panel. That would be cost effective way but not high tech.
I can’t afford high tech right now…my budget is destroyed lol.
Check the schematic I just posted, I think it will work for me. Honestly, I’ve NEVER had a TM on a boat, and I’m sure it will take some time to get used to, so for a while I’ll be using it minimally I’m sure. If it dies it dies and I go back to what I know…stick it pin anchored or regular anchored. EDIT: See your response. I’ve already got the 1/2 switch, so I’ll just use it. Would give me ability to add later if I make some room or come to need it.
Thanks a ton, Andy. Once I get the cable lengths and all dialed in, I’ll probably give you a shout about that crimper. Thanks
Figure out the main wire size you need to feed that circuit, and size your CB to protect that wire. It’ll end up being a little more than the total amp draw from all your accessories.
I can’t afford high tech right now…my budget is destroyed lol.
Check the schematic I just posted, I think it will work for me. Honestly, I’ve NEVER had a TM on a boat, and I’m sure it will take some time to get used to, so for a while I’ll be using it minimally I’m sure. If it dies it dies and I go back to what I know…stick it pin anchored or regular anchored. EDIT: See your response. I’ve already got the 1/2 switch, so I’ll just use it. Would give me ability to add later if I make some room or come to need it.
Thanks a ton, Andy. Once I get the cable lengths and all dialed in, I’ll probably give you a shout about that crimper. Thanks
Wadmalaw native
16’ Bentz-Craft Flats Boat
I couldn’t afford the high tech either, hence me wiring mine this way.
I came close to killing a big ass group 31 on a full day with a full boat. Good thing about isolating it is you can run it all you want, if it dies it dies, so what. You still have everything else going just keep fishing with a stick-it.
Pay attention to the amp hour rating of whatever TM battery you select. I made a big spreadsheet to pick mine, I’ll see if I can track that down.
From what I can find I see the following fuse sizes required:
Bilge - 5A
Washdown pump - 5A
Bait pump - 5A
NAV/ANCH lights - 5A
LED COURT LIGHTS - 5A
Horn - 5A
GPS - 3A
Radio (load says <20A) - 20A
Jackplate - don’t know, but it’s just to power relays - ???
I’m showing 53A without Jackplate.
Wire will be about 2’ long from BATT switch to Fuse Block + terminal.
Circuit wizard says 10AWG is good for that, up to 80 amps. Should I go with an 80 AMP CB? That would be about 33% over my max expected load.
you are WAY over thinking this, its not that difficult.
we use a trolling motor battery as a back starting battery on just about every boat we install a trolling motor on.
you do not need a circuit breaker between the battery and the engine.
andys first drawing is almost perfect, 3 minor changes
trolling motor positive should go straight to trolling motor battery, not to perko.
back light for gauges should be powered from the nav light switch. gauges don’t need to be lighted the entire time the perko is on.
separate inline fuse coming directly from the battery to power the float switch.
other than that, andy nailed it. clean simple, safe, affordable, fully functional.
perko 2 position is only to be used as an emergency power supply to start motor. normal operation will never see perko in position 2.
50 amp circuit breaker should be more than enough for house power
That makes sense to run straight off the battery 2 to the TM. That in effect isolates the TM to Batt 2, so long as the switch is never set to #2 like Chris says there.
Actually, I want my gauge backlights on a separate switch from the Nav/anc. lights. As long as I have space on the panel. Allows you to completely black out your helm area to help save the night vision while keeping the nav/anc lights on for running. Or have anc light on and nothing else at the helm. Or you could just lay a towel over them if you want them on the nav/anc switch.
Anyone wanna wire this thing for pizza and beer? LOL
Seriously, I’ll do it for Paisanos and beer depending on what kind of schedule you want/need it done in. But I would want you walking through the system with me so you understand it and can handle troubleshooting if something comes up in the future. I actually like the electrical system. It’s the final step to reaping the rewards of all the hard work so far. The most rewarding step IMO.
This should be it. Chris’ comments with minor variation/option or two.
Do you want your gauges backlit when your nav/anc lights are on? If so scratch the extra gauge light switch and run a positive out of the nav/anc switch to the gauges.
Are your switches backlit? If so they need to be grounded also.
Why would I be messing with the switch? Couldn’t I just turn both batts on when I depart and have power to TM and to House at all times?
H
I’ve done that before and ended up burning up the rectifier and later the stator. Heck on the little charging system of most outboards to keep up with two weak batteries and accessories. After learning that lesson I also make sure I have a fresh charge on batteries if boat has been sitting for a bit.
Like Chris said, tin you wires and insulate very well. I also like to spray some wd-40/ pb blaster on the fuse panel from time to time. I also coat my battery terminals in heavy grease.
For your battery terminals and bigger connectors try using solder slugs instead of crimping. Was in Fastenal the other day and was surprised at their electrical connector selections and price on bulk.
Anyone wanna wire this thing for pizza and beer? LOL
Seriously, I’ll do it for Paisanos and beer depending on what kind of schedule you want/need it done in. But I would want you walking through the system with me so you understand it and can handle troubleshooting if something comes up in the future. I actually like the electrical system. It’s the final step to reaping the rewards of all the hard work so far. The most rewarding step IMO.
The process of doing it isn’t really what I’m worried about, it’s all of this that you guys are getting me through just by reading this thread. Actually having someone capable enough to talk the right way to make me “see” it has made all the difference. I can do anything once I understand why I’m doing what I’m doing…make sense?
But hell, I wouldn’t turn down some extra brain power and another set of hands around. I’m going to go through everything this weekend, make sure I do have EVERYTHING, and get what else I need (terminals/heat shrink/battery cables/etc) ordered and then see where we stand.
