Dual Battery Setup???

Rescue Wagon · 10-07-2012, 09:25 PM

I'm trying to come up with a dual battery setup for my 08 VN900C and have gotten stuck when it comes to the battery isolator. The ones I can find are to large as they are designed for cars and trucks and the other options I find are strictly relays and don't employ any diodes.

Any options I'm overlooking? Could I use one of the relay setups and add diodes to them?

Thanks.

DESERT ANGEL · 10-08-2012, 04:42 PM

what is the purpose of the two batteries,

and what are you trying to do ? if you give more details maybe some one here can help, I used the relay option on my camper to charge the house battery and keep the main bettery fully charged

on my goldwing I have two batteries but nothing separating them both are working all the time

good luck

Rescue Wagon · 10-08-2012, 04:53 PM

I camp a lot with my motorcycle and would like to be able to steal some power for the evening without risking a dead battery in the morning. Also, I prefer to run accessories on a secondary battery and I plan to run a gps, ham radio, and aux lighting.

And can someone tell me if stators are self exciting?

bikerbill · 10-08-2012, 09:06 PM

Quote:

Originally Posted by Rescue Wagon

And can someone tell me if stators are self exciting?

I believe that the alternator is a 'permanent magnet' type. The regulator simply shunts excess power back to ground. (i.e. it's wasted energy)

Have another look at the 'VSR's (Voltage Sensing Relay). I have worked in the boating industry for many years and you are right, the ones for boats, cars & RV's are waaay too big for your use. A VSR will connect the batteries in parallel only under certain conditions so the main battery is 'protected'. The VSR also has the advantage of no voltage loss like a diode based isloator would so it should be more efficient.

Davego · 11-04-2012, 09:08 AM

Get a consent duty relay at auto parts(it will look like old ford starter relay)Pos. on battery one(main bat.) to one side of relay,Pos. of battery two to other side of relay. Connect key switch power to control relay.With key on both batterys will get charged.Hock acesssorys to bat #2.No power will come from bat #1 unless key is on.Rember you only have a 35 amp alternator on the 900.If you run #2 bat. way down alt. will have to work hard to recharge it and run the bike.Good luck hope this helps. Enjoy the ride. Dave G. Tampa fl.

whoaru99 · 11-04-2012, 09:14 AM

^^^

Yup, that's what I'd do with one exception. Wouldn't use that style of relay. One of the 30A or 40A cube-style relays (Bosch, Hella, etc.) would be more than adequate to feed the second battery.

Oh, and don't forget fuses first in line off your "hot" sources.

That said, I do wonder what the effects might be of the second battery backfeeding the starter circuit. Not concerned about the starter, just about the relay, fuses, etc. with the starting current draw. Would be easy enough to put a diode inline though to prevent that backfeed. Diodes though drop voltage and are less efficient than the relay method.

Suppose could use two relays in series. One that closes when in ON/RUN position and one that opens when you hit START. Or, we could assume relatively safely, I think, it's not going to be a problem and just use the single relay.

Davego · 11-04-2012, 12:09 PM

Your right a bosh type relay should work.I am thinking of bigger charging system I have worked on is why I said bigger relay. That should work fine, just control it with the run relay that works the headlight.Then should not get starter load on the bosh relay when starting.It would only close after bike is running and then charge #2 bat. I am getting old and forget.Thanks for the reminder 99.Have a great day.