Adding a Battery and moving a VRO

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Permalink Reply by Henry on November 3, 2009 at 5:58am

Generally speaking, batteries charged by a single source (motor), should be isolated, with a battery isolator
that uses a feedback wire to ensure that both batteries (especially with the two being different types) are fully
charged. The motor's alternator is not likely to handle a large draw from the house (deep cycle) battery, so having
a large enough one to start with, and having an onboard charger to keep them "topped off" when at home will
help. If you intend to use the deep cycle battery as a back-up start battery, it will require a battery cable run the
distance, and a switch for it. On my boat, I run a crank battery for each motor, and a very large house battery.
My motor's (2001 Yamaha 250 ox66 sw2) were factory wired with auxilarry battery charge leads, thus simplifying
the addition of the extra battery, and eliminating the need for an isolator. I am not sure about Johnsons however.
An inline fuse would also be necessary.

For a newer motor (non Carbed), with the VRO setup, I myself would not mess with it. It ensures that the proper
mix is maintained, and has the safety's if a problem occurs, or the tank runs low on oil. Also the fuel in the tank
is easier to stabilize without the oil premixed. (always carry an extra container or 2-stroke oil onboard - in case
someone forgets to check the tanks level perodically).

There are many boaters fourmn's, but the two links below are ones that I can search, and generally find answers
to whatever tech questions I have, from someone that aready experianced whatever problem I have.


www.thehulltruth.com/ http://forums.iboats.com/

Henry
Wile E. Coyote

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Permalink Reply by R. Kirby on November 3, 2009 at 6:06am

Thanks for the advice Henry. I found thehulltruth and am getting a good response from my post.

RJ

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Permalink Reply by Larry Mac & Ernie on November 3, 2009 at 6:50am

Locating the batteries,fore-and-aft, to optimize trim is a good idea. Good quality marine cables, properly rigged, are essential to minimize voltage-drop reliably. Use an ACR to isolate the batteries. West sell a nice one for <$100

http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/...

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Permalink Reply by Jeff & Rhonda on November 3, 2009 at 8:08am

I want to elaborate on the deep cycle battery issue. Being in the Marine repair business for 24 years I see too many cases of deep cycle batteries being installed where they should not. Too many people refer to deep cycle batteries as "marine" batteries. They have a specific purpose. They are built differently and are more difficult to charge.

A deep cycle battery is designed to release lower amperage for longer periods of time. This is good for trolling motors and "house" equipment such as lights refrigerators electronics ect. Thus the charging systems deal with this differantly as well. If you ever try to give a deep cycle a quick 50 amp charge it will not take it. A good deep cycle will only accept about 10 amps of charge and when it is run down it will need more time to charge regardless of charging amp availability. This is why bass boaters will always have to plug the boat in early the day before.

Starters suffer from low voltage starting. If you are starting your motor and the proper amperage is not delivered to it, the starter suffers from heat build up and acquires wear. The more often this happens the shorter the life of it. The ratings marked on batteries are always the best under perfect lab conditions and can't be counted on. If a battery is marked 650 cold cranking amps, better count on 75% of that. If your starter wants 125 amps to start your motor a deep cycle delivering 150 amps is not going to be nice to it.

Combo batteries deep cycle /starting are poor attempts to doing both jobs. If this were truly possible then there would be no need to make both. Alternators are better charging systems than stators. Stators don't like having a "load" on them for long periods of time. Starting batteries will dump the amps quickly for starting and will take as much amps that the charging system will deliver and quickly top off releasing the load on the charging system.

Unless you are running a trolling motor, there is no real need for a deep cycle battery on a small boat. Also you are not likely to run for hours at a time to allow charging of a deep cycle. Your 90hp motor has a stator and as mentioned would not like to constantly be charging one. If you do have a trolling motor an isolator would be a good thing because any time you have a battery switch joining the two the starting battery will be trying to charge the deep cycle. It would also be best to use a trickle charger on the deepcycle overnight before using the next day.

Unless you have need for a deep cycle, use starting batteries and a dual battery switch. Also know that for a long run from the console to the motor you will need 2/0 cable to insure proper amp delivery to your starter over that distance.

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Permalink Reply by Scott on November 3, 2009 at 12:01pm

I am learning something here too. I have a 17 ft as well with battery under the console starting/deep cycle but it is time for a new one. I have digital guages and when running they flash 16.0 on the amps not sure why it is doing that boat always starts. I do not currently run a trolling motor but boat is prewired for one and I can add a deep cycle when that happens. I guess it wuold be better to switch to a starting battery for my immediate needs. With a 90hp what is good amps that would give me more than enough??

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Permalink Reply by Jeff & Rhonda on November 3, 2009 at 12:56pm

A standard 550 600 or 650 cold cranking amp "starting" battery is sufficient. I just buy wal mart batteries (everstart) because the price is good and the rotation of stock is high. There are many brands but only a few manufactures. I assume your guage is showing you "volts" not "amps" You motor has a regulator on it which is suppose to cut off charging at 13.5 to 14.5 volts. when this regulator begins to fail it allows the volts to increase. Total failer would allow the volts to be extremely high and cold cause damage to lights and other equipment. (very rare cases) Most commonly regulator failer results in an open circuit and stopps the ablity to charge completely.

A sign of 16 volts is not at all alarming and really requires no action at this time. if this voltage gets higher or exceeds 20 volt then you should have something done. when the guage is reading the 16 volts, try turning on some lights and equipment. the less equipment required to reduse this volts reading the lesser the concern.

This may also be solved by installing that new battery as in some cases the battery itself may be tricking the regulator to not stop charging due to a weak cell. If your battery is old and you suspect it then this is probably your culprit

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Permalink Reply by Scott on November 3, 2009 at 1:28pm

Ok great advice Jeff Thanks. Yes thats correct it is showing volts it probably is the battery so better replace it as it is cheaper than engine repairs. I was worried about those walmart batterys but now I see they are ok. Thanks again

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Permalink Reply by R. Kirby on November 3, 2009 at 8:03pm

I will not be running a trolling motor. The only things I see that I would be running for an extended period of time, other than nav lights would be a CD player or live well. I already have the starting and deep cycle batteries and would like to use them to keep costs down if possible. I posted on "thehulltruth" and have recieved about 50/50 for ACR and no ACR. What do you recommend in my particular case?

My run from the consel to the engine is about 8'. Do you think I need 2/0 wire? I was thinking 4 gauge.

Thank you for your advise.

RJ

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Permalink Reply by Jeff & Rhonda on November 4, 2009 at 5:06pm

Yes I think you need 2/0 cable for this. It will last longer and make up for the extra expense. With both types of batteries installed I would route the live well to the deep cycle. This way if your running the live well while not running the motor you should get long run times. The ACR (auto charging relay ) is a good question. They do offer the abilty to have both batteries connected and not lose your starting battery ability thus keeping each battery for its purpose. The cost is a bit high and extra wiring is involved to get full benefits. Its kinda "state of the art" and if its worth it to stop looking at the volt meter to see if you battery is dead then you might look into it. Of course you can just use your batt switch. These type of installations would be more common on larger boats where accessing battery switches in less convenient

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Permalink Reply by Capt. Rick Rescott on November 4, 2009 at 4:06pm

I would not remove the VRO, like Henry said it is not worth tinkering with the new systems. If you do move it keep these thing in mind. Place the tank so that:

1. It is easy to fill with out making a mess.
2. Make sure it is easy to see how much oil is in the tank.
3. How much water will be around the tank in the bilge.
4. Will water pour over the tank every time you open the locker/hatch.

Also, John at Beach Marine, behind Sunrise Marina, sells the Evenrude 2 stroke oil in bulk. You will need a 1 gallon container and he will fill it for $22.00. We always carried 3 gallons on each boat when we ran the E-Tecs.

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Permalink Reply by R. Kirby on November 4, 2009 at 6:32pm

Thanks for all the advice. I am going to keep the VRO where it is and just use a switch for the dual batteries just to keep it simple.

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