Trojan Boat Forum

yorklyn wrote:....the breakers are part of the factory system.....

That may be in your case Todd and that's okay. I'm just letting everyone who is considering rewiring know in case their current system doesn't have breakers that it is not a requirement.

I like the idea of the biggest battery box.... It gives you the ability to have the highest AmHr batteries. Also I'm not against the single battery for two engines... Start with new and have a solenoid backup switch you should be fine. Usually we have battery problems because we drain them trying to start a problematic engine..... A well maintained boat should not reach that stage.
Put fuses solenoid sect: on an adjacent rack to the box.
Consider 6v for weight vs handling reasons....... I need help getting my 160lb battery out..... The 60lb'ers I handle fine!

I would consider adding a neg cable from each battery to the neg bus bar that is equal in guage to the pos cable that leaves that same battery. In you diagram, current from all three batteries will flow out a single cable to the load and you run the risk of over-loading that single cable.

Thanks for the info. Please let me know how the HF crimper works. I pulled out my battery box today. To say its a mess is an understatement...
Wasn't sure if the relay was good or not. Looking forward to your project so I can copy it

I have the HF hydraulic crimper and it has been my experience that it works wonderfully on those large lugs. It puts a solid crimp on lugs. Incidentally for smaller stuff I only use a crimper that puts a clear stake indention into the connector as I have seen too many connecter come loose using the cheap wire striper crimpers sold around.

Harbor freight sells a small red handled double crimper for the small red,blue and yellow terminals . I bought it as a back up to my $90 ancor crimper. I think I paid $8 for the harbor freight and it's exactly the same as the ancor one. Makes great double crimps.

I'm getting closer! spent the last three days "studying"!!
Heres where I'm at:
-three marine starting batteries and four 6v trojan T105 golf cart batteries (got a local price of $122 with out core deposit)
-each engine will have its own dedicated starting battery , generator will have its own as well and will only be charged by the gens alternator. will have solenoid to combine starting batteries in case of an emergency
-two sets of of six volt wired in series then paralleled into a single house bank for 450ah
-mastervolt 40 amp 3 bank charger will connect to the two engine starting batteries and the house bank
-i plan on using one of my existing alternators to charge the two engine batteries. im leaning towards an acr to isolate them.
-looking into a 130 to 150 amp high output, hot temp rated alternator hooked up to a multi stage voltage regulator to handle the house bank.
-still not sure about where to put the main battery switches. I believe that their main use will be to kill power in an emergency as I wont need them for management purposes.
-I will have appropriately sized fuses within 7 inches of each battery.

I know I missed a few things but I'm not done my research yet

How does this look for estimated house loads for a 24 hr period?
-nova kool fridge 2.2 amp x 12hrs= 27 ah (mine was made in 1996, my same model is currently made so I used the spec for it)
-anchor lite 1 amp x 12 hrs= 12 ah
-vacuflush 6amps "say" 3ah
vhf 1.5 amp x 8 hr = 12ah
radio 2 amp x 10hrs= 20 ah
fresh water pump 4 amp x1 = 4ah
cell phone charger 2amp?? x 3 hrs= 6ah
interior lights ?? 12 ah
Total 96 ah used so say 100 to keep it easy
using only a 30% drain on my house bank I would need a 333ah bank
4 t105 batteries will give me 450ah so I have a good buffer which should prolong the life of the batteries as long I i properly charge and maintain them.

you know what they say, "pay a mechanic to rewire a guys boat so he can go fishing and he'll catch a fish (or at least lie about it!) Teach him how to do his own wiring and he'll over think it, over engineer it and spend so much time and money on it he'll never make it out fishing, be too broke to eat at a good seafood restaurant and will have to settle for a fillet-o-fish sandwich at mcdonalds!!!!"

Sound's like you've got a handle on this Todd.

my "newly rewired" battery box has been "un-wired!"
I Re-purposed the old engine bed angle and used it to support the based of the new battery box that im building.
I needed some extra depth in the battery box to fit the new 6volt batteries. if you look at the pictures you can see the old caulk line that was the top off the old battery platform. with the base lowered I have around 12 inches to the bottom of "generator" platform.
The base is 3/4 marine ply. I plan on using 1/2 for the sides and glassing it together with west system. I'm estimating it to be 22-5/8 X 27-1/2 on the inside. the t105 batteries are 10.3 L x 7.11W x 11H (say 10-1/2 x 7 1/4) . Figuring I can get all 4 of then in two rows which will take up 14 1/2 x 21 with no space in between leaving me 8-1/8 for a row of 2 starting batteries and spacing. an interstate group 27 starting battery is 6-3/4 x 12-3/4 x 9-1/2 H.
this will leave me 1-3/8 for spacing. I was thinking of using premade 1/4 fiberglass sheets to divide the three rows which leaves a WHOLE 7/8 inch extra room!
may end up buying pre made 1/4 non conductive sheets to make the sides. if I do that I free up an extra +-1/2 in both directions and could fit the generator battery in there too.
Have not found any info on how close batteries can be in a battery box. Anyone think that I'm pushing it???

Heat is one of the battery killers so as long as you ventilate good then you should be okay. There are actually some higher end boxes that are vented with a blower hose leading to hull vents.

was actually considering that! lol

The batteries don't need a battery strap since they are inside the box? None of mine have one, and it doesn't look like other battery boxes do.

The standard is that they must not be able to move more than 1". However, I do not like the batteries to move around at all. In my last boat there was a fiberglass box built into the hull for 2 8D's in each box. There was a little play in the box, the batteries could move about 1/2". So I made some shims out of starboard and took out all of the movement. It worked quite well. I did not like the idea of my batteries sliding back and forth on every wave...

Made the box, will fit all 7 batteries! dry fit it , fit perfect! then realized I'm a dumb ass!
luckily I caught myself before I epoxied it. forgot to take into account the bolts that hold the aluminum angle for the engine beds!!
Does anyone know of any reason why I cant use the actual stringer as two sides of my battery box as long as as I isolate and cover the bolt heads???? wondering why I cant epoxy the bottom and two other sides to the stringers to create a battery box. i figure i can use 1/4 fiberglass sheets to cover the bolt heads . im just brainstorming at this point. would love to have a single battery box in a central location. thought I had it but guess not, at least not yet.