Battery set up help

Salty Walty · 03-06-2004, 08:27 PM

I am putting in a second battery this season and would like some suggestions on set up. I run a graph, GPS, VHF and CB. I will use both main motor and kicker for charging and I am installing a battery switch. Which combinations have worked best for you. Any help would be appreciated.

WP · 03-07-2004, 04:10 AM

I have not isolated my electronics from the main system and have had no problems (yet). I run the power feed from the "out" post on the Perko switch so they run off of either battery (or both but I run on one and alternate.) I know it is "best" to have a separate power source for the electronics, or to isolate them so you don't have the interference from the engine, but I have not ever found it needed. The only thing I have ever had trouble with is hooking up an old AM/FM radio!
If in doubt, have your local electronics shop install or check out your installation set-up.
Dave

WaterDog · 03-07-2004, 06:38 AM

I just finished installing a second batt in my boat the other day. Used a perko 8501 switch. I thought about getting a true deep cycle for electronics but didn't go that way. The install was easy other than squeezing 2 group 24 marine batteries in a small space. Now I can run my new VHF, fishfinder, and GPS all day knowing I'll still be able to start the main motor. :grin:

NAUTI-NOTIONS · 03-07-2004, 09:27 AM

I run two battires off a perko battery sel switch. however off of one battery a ran a 8 gauge wire to a fuse panel and run all of my elect. off of that, i put a small pwc battery disconnect in lead leading to the panel. that way i can rest assured that all power is shut off. the only thing i have connected direct to the start battey is a auto bilge pump. just in case something should happen durning the night or when its left attended in the water. at home i can sel both batterys on the switch and hook a charger to the teriminals and charge both batterys at the same time. there's not enough post to connect everything to the selector so i installed to two terminal post. 1-3/8" and 1 -5/16" aval. thru go marine. and connected eveything to them.(downriggers kicker ect. ect.) i mounted everything on a peice of uhmw. which is a cutting board type material. i could post a pic.
i fail to mention on that same piece of uhmw i also mounted a battery isolater. Ill try to get some pic by mid week. worked it out on paper first and then mounted it. came out really clean. my biggest problem is with my type of fishing i'm starting and stopping the big motor jumping back and forth to the kicker. I didn't want anything to interup the power source to my elect. the way i did it is that both batteries are reciving a charge from the big motor but only the battery selected will recivie a charge from the kicker, unless both are selected. however when you go to start the main motor the selector must be in #1 to aviod power to the electronic's.
Sam

[ 03-08-2004, 12:48 PM: Message edited by: NAUTI-NOTIONS ]

Tinman · 03-07-2004, 01:54 PM

Nauti, please do post a pic or a schematic. I like your setup.

backlash442 · 03-07-2004, 04:55 PM

I ran two deep cycle batteries with Perko switch. You can run all electronics from either one. Auto bilge runs directly to the batteries and goes on even when the switch is at off. Replaced the original wood board the batteries sat on with some type of plastic. Wasn't really like a cutting board but great material.

jukemove · 03-08-2004, 12:02 PM

what about a battrie minder are you planning to install and if so what is a good one, that will last a long time
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Pilar · 03-08-2004, 11:38 PM

2 batteries is good because there is no pullstring on the mercruiser. I use a deep cycle Group 30 for all the important electronics and a marine starting Group 24 for the motor. This deep cycle battery is a Die Hard and is rated at 110 amp hours. It has lasted as long as 3 days of offshore fishing without a charge and would still crank the motor. This is tied to the 12 volt system with a perko switch. The Deep cycle sits forward in the boat and the starting battery is right by the motor.

I run the boat on #1 (Starting battery) while cruising and shift to #2 (deep cycle) if anchored or shutdown for a long time. On long trips the #2 battery gets charged on the way in by selecting #2. Otherwise I just overnight charge the deep cycle after every trip with the special deep cycle charger. This saves the cranking battery for continuous bilge pump action if that ever happens and leaves it topped off for cranking the motor. Starting batteries do not deep cycle well and this is prevented by using #2 to run the boat when shut down. Also it isolates the electronics on battery #2 from the alternator and the noise generated there while the switch is on #1.

Because of voltage dropout issues (GPS resets) when the engine is cranked I connect the GPS, sonar and radio directly to the deep cycle battery through a buss bar and fuse set up. The fuses are the bullet inline waterproof type and the buss bar is homemade. That way the radio GPS and sonar are always hot and they can be switched off at the device. The forward battery is connected to the Perko switch and the engine block with two 250MCM welding ground leads to take care of the lead length (25Ft total) and allow the engine to easily start off the forward battery.

The float activated bilge pump is fused and connected directly to the starting battery.

All other loads on the boat are switched through the perko switch and the fuse panel.

Another thing for added reliability and to reduce wire count ... the ground side of every load is terminated near the load at a negative buss bar. There are 2 of these, with 20 connection points each, 1 forward and 1 aft. They are connected to the negative side of the battery cables and the ground point on the engine block with #8 wire. All connections of either polarity are soldered, cut insulation ends sealed with liquid vinyl and covered with marine grade heat shrink. In below waterline connections I use RTV instead of liquid vinyl. Any exposed connections to terminals, battery posts or buss bars are coated with battery post sealant to prevent exposure to seawater.

Any wire failure results in using an installed spare wire and splices are never used because they are so quick to fail.

[ 03-08-2004, 12:39 PM: Message edited by: Pilar ]

NAUTI-NOTIONS · 03-08-2004, 11:53 PM

Pilar - it sound like we're about even except i like your grounding plate idea's
thanks
Sam