multiple battery upgrades

[jditty]

I recently purchased a 16' aluminum boat with 40hp evinrude all from 1991 (12v trolling motor). A home made recharge system was installed which seems to make sense but I hate electricity....mainly because I dont understand it so I would appreciate any comments as to whether it needs addressing or not from a functional and/or saftey stand point.

There were two dual purpose batteries on the boat when I got it. One started the outboard only and the other ran the trolling motor and electronics. The trolling battery was bad and replaced by me with a marine type Walmart brand rated for 750 cranking amps and 109 amp hours at 1amp. The maiden voyage last week showed everything works but with just a half day or so regular bass fishing with the trolling motor I got home to see the battery was worn pretty low. The only tester I have is a cheap green/yellow/red light tester so I cant say for sure how low it was. To make sure I dont lose trolling power during longer days and gain confidence I can run the radio when the Cardinals are playing (which wasnt used on the first trip) I added another deep cycle battery that I plan to wire parallel tonight.

With that picture, my question has to do with the "recharge assistant" that was installed on the lowe covered compartment. The original trolling battery was tucked away under the rear deck so a new terminal was added near the opening to the covered compartment. This recharge terminal consists of two cut pieces for floor board (house floor board with a slight notch out of the rear). The first piece was bolted face to boat with the recessed notch facing out to the battery compartment. The second piece of floor board had two terminal bolts added so the bolt head could be squeezed between the two wood recesses. This piece was screwed with separate screws (dry wall screws) to the first so that the terminal bolts are surrounded by wood on all sides. A washer was added to each terminal bolt to create a metal surround and all trolling motor and accessory wires were connected to these bolts along with the trolling battery feed.

Is this causing any un-necessary draw on the battery when everything is connected and stored?
Are there any issues with using these remote terminals to continue to charge the new batteries?
Now that I have two batteries in parallel should anything be disconnected when not in use?

Thank you for your advise.

 

[Grub54891]

Re: multiple battery upgrades

Sounds kind of like a mess,how about some pics?
Grub

 

[jditty]

Re: multiple battery upgrades

good call grub. a picture is worth a thousand words, which i might have reached trying to describe the pics below. thanks.

 

[UncleWillie]

Re: multiple battery upgrades

The principal is sound, the execution is functional but messy.

I would advise against using wood as the mounting material for electrical terminals.
As long as the wood is fresh and dry it will be fine.
The dampness is going to cause the wood to become a high resistance and drain the batteries over time.

If you were in salt water I would warn that the worse case scenario (Highly Unlikely) would be having the wood conduct and char possible causing a fire.
Not likely, but one of those things you think about at nights.
If you are familiar with salted roads;
You hear every now and then about highway utility poles that arc over and catch fire. Same idea!
But not as likely at 12 volts. Probably just battery leakage.

Change the wood to plastic and sleep well! :joyous:

 

[Don S]

Re: multiple battery upgrades

PowerPost Connectors - Blue Sea Systems

 

[Auger01]

Re: multiple battery upgrades

Did I see a wire nut in one of the photos? That is asking for trouble. Consider instead a heat-shrink butt splice.

Here a a picture of what Don S was talking about:





Batteries left in parallel should always be of the same type and age. If not, differences in internal resistances will cause the batteries to discharge.

 

[Don S]

Re: multiple battery upgrades

I had to look at the wiring again, and it's just a mess. Every battery cable is black. You have terminals that I would guess were supposed to be positive and negative, but with the one on the right having one wire with red tape on it, while the rest on that stud are black, is making me wonder if that's part of your problem.
I see no fuses leaving the studs on the red wires, which is not good. They need to all be fused.

Also, don't expect your motor to charge all those batteries. You just don't have the capacity to do that.

Without knowing more about your "16' boat" it's tough to call how it should be wired.
But at minimum, I would put an on/off battery switch on one battery for the motor, and another on off switch for the trolling motor and your other accessories.

While your battery cables are fine, get some red tape, or better yet some red heat shrink and put on each cable end of the positive cables so you don't confuse them.

A home made recharge system was installed which seems to make sense

Explain this home made recharge system.

 

[jditty]

Re: multiple battery upgrades

thanks guys. looks like i have a little work to do to tidy this mess up but it generally sounds like the system will be okay in concept. i will add plastic blocks, real terminals, better wire coloring for reference and solid terminal bolt ends.

unclewillie, the damp wood (its dry for now) causing the batteries to drain over time is exactly the sort of thing i was questioning so thanks. i will only be in fresh water but thanks for the "one of many" heads up associated with saltwater. maybe one of these days i can move closer to that fishing environment and deal with those challenges then.

Don S and Auger01, those terminals look more legit so i will get some. is that "bar" off the ground just a cleaner way to connect all those wires without lining then up on one terminal or is there more to that than i want to know? also, the two new batteries i got are the same make of marine batteries but one is larger in size than the other (12" wide with 750 cranking amps, 10" wide with 690 cranking amps). will that cause the internal resistance discharge you described when paralleled? the only reason for the size difference is the size of the space they had to fit in. i could replace the larger one with a smaller but not the other way around.

Don S, the "home made recharge system" wasnt well described. it was just the way the previous owner creating the point of connection (wood mounted terminals) for a plug in charger closer to a reachable point in the battery/fuel storage compartment. the two terminal mounts (with the wood) are at an easier connection spot for the charger to connect when i get the boat home than reaching under the rear deck. the previous owner may have had a bad back or something and didnt want to reach back to the batteries. fyi, the boat is just a 16' aluminum v bottom lowe with a bass fishing setup. best i can tell, two of the larger wires extending to the wood mounted terminals are from the trolling motor and the rest of the spaghetti is from the console. all the accessories worked when i took it out the for the first time a couple weekends ago. there are fuses at the rear by the battery and a few in the consol for the various pieces of equipment. the horn does not work which will be my next project. im afraid the overheat warning does not work because the horn does not work. i have been reading posts here on that issue which is also on my "to do" list.

thank you all so much for your help.

 

[Auger01]

Re: multiple battery upgrades

Yes, the separate ground bar is just a cleaner way of attaching all the smaller wires. As a general rule, you dont want to have more than four wires on each lug/screw.

The general consensus is that you dont want to leave batteries paralleled indefinalely unless they are the same make, model and age.

 

[jditty]

Re: multiple battery upgrades

thanks auger01. time to get to work on the fat girlfriend. thats what i named my boat since it was my third choice and as you can see its a little embarassing to show to people but i love her and thats all that matters. word of advise, go buy stock in butt splice companies, ive got wire nuts out the wazoo that have to go.