Best way to wire Kicker w/2 batteries - VSR vs. 2 switches

[Major Tom]

I've read up here and THT and I still need a little advice... I have new Tohatsu 6HP Sail Pro, that charges at max 6A (not much but every bit helps), manual start. Main is Honda 90 with a standard 3 way Perko switch (Off/1/Both/2) to 2 batteries (#1 Hybrid starting, #2 Deep cycle House). This kicker is mostly a backup, although cruising at 4-5knts while charging the house battery is an appealing idea, and I may troll with it too. And you never know, there may be a dicey situation where I'd want to run both engines.

Many years ago on my old boat I spent a few hours in an engine compartment apparently designed by Munchkins from the Wizard of Oz, to replace an alternator. So it's become instinctive for me to check that switches are in the right position, not switching through Off, etc.

I read on THT that new outboards in past 10 years or so have onboard "charging protection" so just connect kicker to same Perko terminals as the Honda. Seems like a very bad idea to me... is that true?

I looked at BEP's site... if I install a VSR, which one should I get, and would that give me the protection and flexibility I want? Wouldn't I still need a switch before the VSR, selecting which engine is charging?

I am also considering a pretty simple approach: Keep existing setup, wire Kicker to a new On/Off switch, then direct to the House battery (with a 6A fuse). This way, whichever engine is to be running, switch it on and the other engine off. And if running both, make sure Main 3 way Perko is on 1, and new switch is on (going to #2 House). Worst case, I always carry jumper cables so I can charge #1 from the kicker if I need to. This seems pretty simple to me and seems like a good option. The only other thing I cna think of is that in an emergency or similar stress situation there's a lot of potential to make a mistake.

Any advice or thoughts? Is there another, better way? What else am I missing?
Thanks!

[Aurelia]

You should be able to wire it directly to the connections used by the Honda so long as there is physical space to do that. The alternators will not hurt each other and your current switching allows you to determine the battery split.

A VSR is a nice item to have as well, and I have been happy with sense models from BEP like this

http://www.bepmarine.com/en/710-140a

But I have also successfully used DC to DC chargers instead such as this:

Advantage here is the ability to mix battery types and sizes more drastically while assuring safe and complete charging.

http://www.sterling-power-usa.com/ProCharge-B-waterproof-dcinput-battery-charger-12volt-12volt.aspx

My favorite unit and what I current use is this one due to its features and small/waterproof form factor plus simple wiring.

http://www.yandina.com/c100InfoR3.htm

Greg

[Major Tom]

Thanks for the reply, Greg. Huh, I've never experienced it, but I've read that connecting 2 engines together will fry the coils or alternators, probably on the smallest alternator first, when both engines are running. 6 amps going into the honda probably won't do anything, but 16amps from the Honda into the kicker might (unless only at idle for short periods of time). Anyway, that's what I've gleaned, but of course I could be wrong.

The BEP system seems pretty cool, the 2 engine/3 battery model, though I didn't find any info saying whether I'd have to get a 3rd battery for it to function properly.

I also found what seems like an elegant, single solution: a dual alternator controller, like this Balmar...
http://www.westmarine.com/buy/balmar--centerfielder-ii-dual-alternator-regulator-controller--12033007

Actually this would do the trick nicely and protect everything in the system, I think. This one is for a single bank but I think I could utilize the existng 3 way perko to select the bank.

Hmmm... decisions, decisions. Think I'm going to try with my last, simple approach by adding an on/off switch for the kicker, and see how that goes. If I dont' like it I'll try the dual alt controller.

As I was looking at BEP system and VSR's I saw that there's not a "bypass" mode, at least not that I could tell, and I like to top off the #2 House battery for the night, so having control of the charging battery is important for me. I've never had a problem with my start battery, that's usually fully charged or close to it. And I think a VSR still won't protect the "dueling alternators" scenario. So I've ruled a VSR out.

I'll probably just make some nice big labels for the switches so I don't make a mistake in a high stress situation. The more I think about it the simpler it seems... even in a pinch, just remember Honda switch on 1 (the 3 way) and Tohatsu to On. And even if I did get it wrong, it should take quite a while for the coil on the Tohatsu to fry. One correction, I think I'll need a slightly larger fuse to avoid constantly blowing... have to research but I'm guessing 7a or something like that.

Thanks!

[Aurelia]

Many boats do run them connected together, but on most boats it is also normal to run only one of the motors at a time. I can't think of a situation where you would have to run both but if you wanted that option and were worried about a possible conflict, a simple switch on the incoming kicker wiring would allow you to keep them from playing together. If you think you need the charging from both motors at the same time, I would only say, are you sure? The VSR does not address the dual alternator connection but does keep you from babysitting switches for house battery management and protection of the starter battery. If you still have quite a few accessories wired to your start battery, moving those to the house clarifies some of the management details for many people.

You could also wire the kicker to the house battery and use your existing switches for some isolation options.

Good luck MT,

Greg

[Major Tom]

Thanks, Greg. To clarify, in case this helps someone down the road, Yes to your first point, that's what my intended approach does, with an on/off switch for the kicker. And it will be wired to just the #2 House battery. (I should probably create a simple schematic at some point in case it helps someone).

I don't plan to charge from both at the same time, although I could do that without harm with this approach. And yeah, I also find it a bit hard to imagine a situation where I want both running, the only one I can think of is a difficult sandbar crossing or similar situation where loss of an engine at the wrong moment could really ruin your day.

Again, thanks!

[Kushtaka]

[Kushtaka]

[Aurelia]

That's sounds like a pretty good reason but I would suggest adding more battery capacity if your accessories are really cutting your current system down enough to run the main as a precaution. One more house battery could save some hours on your main.

Remote control/steering is always a bonus but does take some investments.

Greg

[Kushtaka]

I'm hauling a lot of weight in the stern at this point with the motor, kicker, tanks and two batteries. I don't have room for new batteries at the moment. BUT, I could move them to the v berth after some carpentry, and fiberglassery. Someday I'll add that v berth storage.

Regardless of the battery bank, the owners manual on my puller and my windlass both want the motor running while using the gear.

I think the best thing to do would be to run my generator and use a battery charger (more amps than the motor anyway!) but I don't have a charger yet.

[Major Tom]

I finished the kicker install and tested yesterday. I ended up with my "simple" approach, I just ran 10AWG direct from the House battery, 10a fuse, to a BEP/Marinco 701 Battery Disconnect Switch, and kicker connected to the other pole of that switch.

Very happy with this setup, I'll post some pics in my album.

Kushtaka, the 6a charging alternator on the Tohatsu is a nice plus, and worked well. I don't have a battery monitor yet, but before starting the kicker the battery was reading 12.9v on my fishfinder. At 25% throttle I was immediately getting 13.5, and about 30 minutes later it was 14.3, still at 25% throttle. That's not exactly scientific, but I was encouraged... I need to hookup at meter one of these days, but it does what I wanted, keeps the house battery topped off (although I've read that all outboards won't charge the last 20% like a trickle charger, don't know if that's true).

I didn't plan on it, but I also answered the question of 'why run both at the same time'...

I knew I'd be breaking in the new kicker so I left the main Perko 3 way switch on Battery 1, for the main Honda. Spent a few hours breaking in the kicker, Honda off, kicker at 50% throttle steering with the main as a rudder, so I was at the helm in the pilothouse. At one point I looked over my shoulder and saw a 200' day cruise ship bearing down on me just as we were entering a narrow 50' wide channel. He had been hidden behind an island and came around at full speed... in 30 years I've never seen the day cruise ships in that channel and he was moving. I probably could have made it clear with the kicker, and I don't think he was going to ram me, but hey you never know. I didn't feel I had time to go back and kill the kicker and raise it, so I simply fired up my main honda and took off to a safer spot while he passed. With the kicker in gear at 50% throttle. Worked like a charm, didn't have to think about switches or anything. So right there, on my first day out with the kicker, I found a time when running both engines was a good thing. I know it's still unusual, but I'm glad I rigged it this way... it works for me.