Toom much voltage?

[shirthero]

Installed a volt gauge this last week (cause I like to know whatsgoing on back there...) '78 evinrude 115, brand new deep cycle battery. Engine off I have 13 V, idling 14.5-15, WOT I looked up and was showing 18? Is this okay? I expected to see 14-15 all the time. Thoughts?

 

[ezeke]

Re: Toom much voltage?

It is expected but not really good. You can add a regulater to the system or run something off the battery to help reduce that voltage. Normally a true deep cycle battery will absorb the extra load, but if you had it fully charged to start with, it will read high.

The separate regulater kit was part number 173640.

 

[shirthero]

Re: Toom much voltage?

It wasn't always at 18, but we spent most of the day at WOT draggin the kids around on a tube, and it did settle down at lower rpms. How concerned should I be? Will it blow up other electrial items or is it just not great for the battery? Do I need to run right out and stick a regulator on it?

 

[R.Johnson]

Re: Toom much voltage?

Those deep cycle batteries are really not meant for starting batteries. Are all of you connection tight? Do not use wing nuts on the battery post. Brass, or stainless steel nuts.

 

[shirthero]

Re: Toom much voltage?

Okay, well I have another battery, actually an automotive battery that was in it, I can swap em back around and use the deep cycle for the trolling motor and radio etc which is what I was gonna do with the car battery. Yep I have wing nuts on it...gee it did come with stainless nuts....guess we'll switch that around too.

 

[ezeke]

Re: Toom much voltage?

A dual purpose deep cycle marine battery can be used either way and will generally outlive a starting battery because it can stand deep recharging many times more than a starting battery.

Optima specifically tells you not to use their starting batteries on unregulated rectifiers. http://www.iboats.com/Optima_Marine...72838190--**********.047626646--view_id.52134

I would check the battery company's website for specific recommendations for any particular battery.

Marine starting batteries are for starting. There is much specific literature from OMC and BRP manuals saying not to use automobile batteries with unregulated rectifiers. See the Battery Specifications in the Electrical System section of your factory service manual.