Wet-N-Frugals Projects: Wire upgrade and Dual Battery System

[Wet-N-Frugal]

Wet-N-Frugals Projects: Wire upgrade and Dual Battery System

Per the interest in recent posts: I did these upgrades three-plus years ago.  I’m VERY pleased with the outcome/performance.

The original wiring harnesses on these boats are a bit of a disappointment. With that said, perform a couple of modifications/additions/upgrades and it can be made right. As mentioned many, many times before on this site, every Epic should pull another Power wire from the Battery to the cockpit. For the Medallion Instrumentation is very sensitive to under voltage, and is the root cause of all kinds of screwy behavior from your gauges. Under voltage also stems from poor connections, so I upgraded further.
 
On my 2000 X22, the power distribution nodes were a couple of studs at the base of the DECC… too many wires, on too small a screws… what a cluster farg.  Clean this up by adding two new #10 x 1.5” SS machine screws nearby (see pic); one for +12V and one for common (Batt-). They’re easily added by drilling two holes, over an inch apart, in the fiberglass of dash cavity’s belly. Insert the screws in from above and nut them tightly in place. Move all the wires from the DECC to the new studs respectively. Add to each, a new short #10 red and black wire back to the DECC for its power. Secure each stack of wires with SS nylocks. The new power distribution points are more ‘sanitary’, with room for expansion.

Continuing this theme I added two more distribution nodes for a second battery. The SS studs work slick, but instead I choose two bus bars; again they’re mounted to the belly of the dash cavity. Frankly, the bus bars are more suitable for adding new features (more wires) to the system. Red and Black #10 wires feed the bus bars from the second Battery. A large black wire ties the two common distribution points.

We upgraded the Stereo System (multiple amps), and desired to feed it independent of the Engine power and key switch. The reason obliviously is to not drain the starting battery, AND to help keep the engine noise out of the sound. So I added a dual battery system. The second battery is an Odyssey. Amp-hour wise, the battery has been a bottomless pit. And finally, in all my years I’ve never witnessed a battery with posts offering such outstanding corrosion resistance. The 2nd battery is mounted in the locker using a simple, yet stout tie-down frame. The make is HM, and is all plastic and stainless.

The Blue-Sea battery Switch (6011) is mounted super convenient for the captain, in the passenger seat wall; the backside falls in the seam between the cooler and locker. The switch has two isolated poles for separate circuits. Yet a third switch position will short the two batteries together in parallel, for a dead battery emergency… to accommodate this, a battery cable (black) ties the battery negatives together.

The charging circuit is my own design. The primary battery is still a small car battery that came with the boat… six seasons ago.

-WNF-

[Wet-N-Frugal]

Also here's a quick schematic.

WNF

[Supraman]

I am in the process of upgrading the stereo on my 2001 SX22. What do you think about using a Blue Sea 7610 with our boats? I'd like to automate all of the switching so I don't have to remember to switch the perko switch.

The 7610 will isolate starting so it only draws from the starting battery to start the boat. When the boat is running, it monitors the voltage in the starting and house banks and keeps them topped up. When the boat is turned off, only the house batteries power accessories.

Will a 7610 have the potential to harm the computer on our Epics? I know we have to be careful about connecting and disconnecting batteries without first turning the disconnect switch.

[Wet-N-Frugal]

Supraman,

First, I really like Blue Sea quality.

I don't believe introducing this device electrically is any more harmful then the native exposure already there; in other words, if the computer can withstand the original wiring and starting sequence it will survive this device too.

On the Plus side:
  *  Slick package and circuit.
  *  Isolation with the Engine off.
  *  Clever idea tapping into the starter circuit to provide isolation during heaviest/noisiest current draw... only if Blue Sea used a Fast switching scheme within the 7610. Otherwise the Starter and 7610 are triggered from the same signal, and the Starter will be generating ugly transients while the 7610 is still trying to unplug the ‘House’ side.

On the down side:
   *  With the Engine off, and no manual cut-off, the 7610's ambient power sucks current from the Engine Battery Xor House Battery. i.e.  if the Engine Battery is 65 A-hr, and the boat is idle for 45 days, the battery will lose 25%.
   * No isolation while the engine is running. Other electrically noisy devices like Ballast Pumps, valve solenoids are still on the same power. Not a huge deal, but all the same, an isolation advantage that can be attained.
  *  Can’t  tie both batteries together during dead battery scenario.

I can easily see the down side as tolerable/manageable.

-WNF-

[Supraman]

By using the 7610 in conjunction with a perko switch it will allow you to combine both botteries together, or select just battery one or just battery two to start from.

Do I also need to keep the stock on/off switch if I go with this system? I think it is redundant, as the Perko can just be switched to off...Here is a wiring diagram:

[Wet-N-Frugal]

I do like Blue Sea Switch: Always start from the same Battery. House battery always isolated. The Switch provides the 'Combine' option on those rare occassions. Not quit sure I understand the switch symbol on your schematic, but overall it's similar to mine... substitue the 7610 in for my charging circuit; the 7610 requires a Common as well.
The 7610 requires 15mA just to power itself. Whatever leg A or B the 7610 it draws this power from, I suggest you interrupt the connection with that battery via the Switch. Quickly scanning the 7610 documentation, I can tell what leg that is???

Are you going to put the battery (perko) switch in a different location? If not, then replace the old with new. As mentioned previously, I introduced my new switch in a different location. And thus didn't feel the need to restring new runs from the new switch to ALL the old locations. Rather I pulled a new battery cable from the new switch to the old one; tying all runs at the old switch to the same post (defeating the switch).

[Supraman]

The switch in that diagram allows you to select your starting battery. Position one will start from the starting batteries, position two starting from the house batteries. Switch it to combine and it will combine both batteries for starting. It will almost always be in position one (or off when the boat is in storage). The only time it would ever be inposition two or combined is if the starting battery failed.

I think this system will allow me to eliminate the factory On/Off switch.

My boat currently has both the factory on/off switch and a perko switch mounted in strbrd locker behind the drivers seat. I think that the factory on/off should have been bypassed when the perko was installed... I don't see a reason why we require two off switches.

I plan on leaving the aftermarket perko where it is now. The starting battery will be housed in the factory location and the house batteries will be stored at the front of the port side v-drive locker.