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The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
Unlike a marine 3-stage battery charger with a battery temperature sensor, an outboard regulator I assume is quite simple, designed only to maintain output voltage between about 13.5 and 14.5 Volts. My question then is on an extended run at cruising speed (2-4 hrs) is the battery at risk of over-charging? Let's assume the regulator is working properly....although I understand that may not be a valid assumption for older outboards.
Unless the voltage regulator is faulty, it essentially responds to the "back pressure" of voltage from a fully charged battery--just as it does in your vehicle, which you can drive indefinitely without "boiling" your battery.
Dave Bristle Association "Port Captain" for Mystic/Stonington CT PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired), Now on Eastern 27 $+!nkp*+ Sarge
That makes sense Dave. The context to my question is that I saw very little boat time last summer except for one weekend late in the season in which I rode a passing front out but had to motor back. When I checked my boat battery this past weekend I was surprised to see the water levels were very low...still above the plates but not by much. Just trying to understand why.
Sounds like a normal amount of water loss over a year for a standard vented wet cell battery. FYI I check and top off my battery 2-3 times a year. Battery's are vented to the outside air so you will have gassing and evaporation.
Scott-"IMPULSE"87'C25/SR/WK/Din.#5688 Sailing out of Glen Cove,L.I Sound
Gerry, You might want to also monitor your alternator voltage next time you’re out running the engine. I have a LED-based battery monitor with five sequential indicator lights that I purchased at Walmart or the auto parts store.
The lights indicate: Red - 11.8-12.0 VDC..........Battery Discharged Yellow - 12.1-12.5 VDC......Low Battery Green - 12.6-13.0 VDC.......Normal Range Yellow - 13.1-13.6 VDC......Charging Red - 13.7-14+ VDC...........Overcharging
Way back when, I had switched off the battery switch while the engine was running. That damaged my regulator, but did not destroy it. The alternator was constantly connected to the battery, so the regulator was not switching in and out, overcharging the battery. After a little while, I smelled rotten eggs - a sign of the battery out gassing H2S. I disconnected the engine right away. I had to replace the regulator afterwards.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.