mspring135

I'm new to boat lifts, I've always had a slip in the past. For a 2006 Elite C4, I'm thinking that a 4000lb lift will be enough. NADA states that the dry weight is 2900 so I'm thinking that I am at ~3400-3600. Does that sound right? Is anyone else with the mid 2000's centurions running a 4000lb lift? I searched and saw that a couple guys have 4000lb lifts for the same year Avy which is a bit heavier. She's in the water now, otherwise I'd find a truck scale and weigh it on the trailer. Thanks!

Good point on the isolator max amperage, I missed the fact that the 150A fuse to the aux battery will blow if you try to cross connect to start using the battery doctor. If I add a 6011 switch or equivalent, that should enable me to keep the circuits separate as well as interconnect for a dead starter battery and bypass the VSR, correct? I definitely overthought this one and came up with a dumb plan, thanks for the help. I'm still a little hesitant on the ignition wiring, specifically, having the ignition circuit on the starting battery and everything else powered from the fused distribution block from the other battery would result in the two batteries being connected, i.e., voltage differential, somewhere down the line in a relay, sensor, etc. I would not think that this would be the case but want to make sure before something gets fried. To test this out so far, I lifted the + 10 AWG lead to the distribution block as well as the ignition lead from that same block. I used a fused test lead to power just the ignition lead and verified that all necessary things to run the boat (gauges/ecu/starting circuit) have power which lead me to believe that I would be okay splitting out the power sources.

Let’s take the switch out of the conversation for now since it’s not really necessary with the battery doctor isolator. If I do the following, what issues do you see: 1) Wire the isolator per the diagram from battery doctor. As I understand it, this should maintain both batteries charged and allow connecting them for a short duration to start in an emergency. 2) Run a cable from the auxiliary battery + to the fused distribution block under the dash so that all the house loads (except ignition and gauges, below) run off the new battery. 3) Move the stereo system power to the aux battery. 4) Retain the original distribution block + cable to power the ignition lead which will be moved off of the factory fused distribution block to a new fused line. This will retain the ignition circuit/gauges on the starting battery and shouldn’t cross power paths with the aux battery hotel circuits as far as I can tell looking at the Merc 350 Mag MPI schematics. Thanks!

I was thinking like this, only with the switch only handling the house load power source not two different circuits since the isolator can connect both if needed for an emergency start.

I appreciate the help on this, I may need to re-draw to better show the arrangement. The way that (ideally) I am looking to have things wired would be to either have power being fed to the “house” loads from the aux battery or from the original hot lead which is powered from the starting battery. Also, I want the isolator to recharge both batteries without having to flip a switch, which as I understand it, is what the battery doctor style isolators do. This way I can sit with ballast, stereo, lights, etc. without having to worry about being able to restart should the aux battery die. I see now that I also would want to keep the fused “Ignition” lead under the dash fed from the original hot lead from the engine bay/starting battery to accomplish this. I was trying to avoid wiring a new second distribution block for the house loads since really all but the ignition lead (gauges/starting) would be moved over to a new aux block.

I also realize that it looks like a child’s drawing lol, please don’t let that distract from the question.. To clarify, the line running from the “engine” to the “2” position on the perko is just the factory lead that goes to the fused distribution block currently.

Which part specifically, the battery doctor isolator is wired per their drawing. I also understand that the perko switch is not wired typically to the battery but rather further down the system.

Here is how I am planning on wiring my system. My idea is that the isolator should automatically maintain both batteries charged and the "house" loads from the fused distribution block can be run completely off of the new lead coming from the Aux second battery, which will also be charging while the boat is running with the isolator working. If for some reason the Aux battery dies, I can use the Perko switch to re-align power to the house loads from the factory lead that was lifted and moved to the Perko switch from the starting battery. The isolator can also be overriden to connect both batteries in parallel if the starting battery is dead. I just want to make sure that I'm not overlooking the way that things are connected back in the engine compartment and inadvertently have some weird circulating current or interconnect the batteries through the engine bay wiring.

I have an '05 Elite V C4 and I'm in the process of wiring dual batteries with a Battery Doctor Isolator. Hooking up the isolator is straight forward per their diagram. I have a deep cycle battery for the second auxiliary battery and a cranking battery for starting. The question that I have is regarding swapping over auxiliary equipment to the Aux Deep Cycle Battery (#2). I would like to do more than just hook up my amp and stereo to this battery. I found the distribution block with all of the fuses for lights, ballast, stereo, blower, bilge pumps, etc. under the dash (see attached). Can I disconnect the power feed wire for this distribution block (top, red, 10AWG wire that is coming from somewhere in the engine bay) and run a new lead to this distribution block directly from the Aux Battery? My concern is that if I feed this block from the new Aux battery and then run the engine (all of the gauges, sensors, ECU, etc. are now powered) is there going to be something that is now being fed power/connected to both the starting battery and Aux battery? I can't find any wiring diagrams for these boats to see where the power branches off from the main cable (starting battery) (ECU, sensors?) and would also potentially be provided power by that distribution block that is now being fed from the Aux battery (most likely what ever that ignition fuse powers, top right, yellow 20A). Thanks!