I’ve just purchased my first boat and am setting it up with a 24 volt trolling motor and an on board charger. After seeing all the boat wiring info on your site, I just have a couple questions to make sure that I get it right.
- If I’m installing a VSR do I need a two or three bank charger for charging my batteries with shore power? I have two deep cycles for the trolling motor and one cranking battery for starting my big motor.
- I would also like to install an on/off battery switch, so when the boat is not in use, everything is shut down. Where should this be placed in the marine electrical system?
Everything else seems straight forward after visiting your site.
Thanks for all the info!
There are two types of VSRs.
12 Volt Systems
The VSR is connected between the positive posts of two batteries. The negatives are connected together. This type of VSR works great for multiple battery systems that have a common ground and only operate at 12 volts.
24 Volt Tolling Systems
In this case, the VSR is the only connection between the 24 volt trolling motor batteries and the 12 volt engine battery. This type of VSR charges battery 1 of the trolling motor system for 1 minute and then charges battery 2 of the trolling motor system for 1 minute.
For your marine electrical system, I would recommend the 24 volt VSR. You could use the 12 volt unit to charge one of your trolling motor batteries, but the second trolling motor battery would only be charged by the battery charger.
I would also recommend a three bank battery charger.
Size your charger based on your desired recovery time of your trolling motor batteries. (Decide of you want a few hours, overnight, or 2 day recharge time) The charger output to the engine battery can be minimal (3 amps). It is more of a maintenance charge than a recovery charge.
As for the battery switch, install an On/Off Battery Switch near your starting battery. Connect all emergency circuits to the battery side of the switch (bilge pump, horn, etc) and connect non-essential circuits (nav lights, docking lights, etc) to the non-battery side of the switch. Connect your existing engine battery cable to the non-battery side of the switch.
Let me know if you have any more questions,
Thank you for your quick reply.
I just have one other question. Do I hook my on-board charger directly to each of the three batteries, independent of the cables with the VSR?
The charger connection points will depend on where you are mount the charger and the type of wiring it comes with.
One option is to connect the charger directly to each battery. Another option is to connect the charger at the VSR. The Trolling VSR has three sets of wires that lead directly to each battery. A third option is a combination of these two ideas.
My preference is to only have one positive and one negative cable connected to each battery post. I realize this is not possible for some applications, but the more you can reduce the confusion and clutter when reconnecting batteries, the better your marine electrical system will be.
I have purchased all of my boat wiring components and am ready to install.
I just have two other questions before I start, so I get it right the first time.
- For leads from the starting battery, do they go from the battery to the switch then the VSR and then the motor? Or, does one set goes to the VSR and another to the motor via a switch? As you recommended, my on-board charger will attach at the VSR for all the batteries.
- I am having a hard time finding 70 amp fuses or circuit breakers, so is it OK to use 50 amp ones?
Thanks for all your help!
- The leads from the starting battery go to the switch. Two sets of wires leave the switch. One goes to the motor and one goes to the VSR (through your circuit protection).
- 50 amp will work fine. If your engine alternator is large enough, you may have a nuisance trip problem with the circuit protection on the lead between the VSR and the battery switch.
Let me know if you have any other questions,