optima - HeLP, I'm over charging!

[fla.sailor]

Hey folks,

Our new to us cat has a honda 4 outboard that is putting 16+ volts to our 2 optimas. I'm a little concerned that this kind of over charing will murder the bats. How can I control the volts going to the optimas other than setting the battery setting to none???

thanks!

-dennis
'91 gemini 3200

[never monday]

I'm wondering if the Optimas are bad and giving false info to the charging regulator.
As an aside, I've had poor luck from the orbital design batteries.

[jscott]

I got two honda 4 strokes an 8 HP and a 225 both put out a steady 14.7 volts.

I think its the honda.

[cal40john]

Below a certain engine size, outboards tended not to have a regulator as the alternator was considered too small to overcharge the battery. I can't find data on the Hondas so I don't know about them. I'd be surprised though that an alternator that small could drive a battery to that high of a voltage unless it was run a very long time.

Our club had chargers on small outboards, everyone was told never hook up the engine without the battery, so of course it happened. I was wondering why several of the lights weren't working, and the bulbs all had a mirror coating. Without a battery in the circuit an alternater (without a regulator) will put out 50 or more volts. All the filaments had vaporized and redeposited on the glass. This happened enough years ago that the boats didn't have anything more sophisticated than light bulbs, now VHFs and knotmeters would hopefully blow fuses before dieing.

John

[Therapy]

Originally Posted by fla.sailor

Hey folks,

Our new to us cat has a honda 4 outboard that is putting 16+ volts to our 2 optimas. I'm a little concerned that this kind of over charing will murder the bats. How can I control the volts going to the optimas other than setting the battery setting to none???

thanks!

-dennis
'91 gemini 3200

<edit>
What year???

I could not find a manual online (free to look at) but I did find this.

Honda Repair Advice, Service & Troubleshooting. How To Help From Honda Service Experts - JustAnswer

[Tropic Cat]

Anyone have an idea of how a 10 amp alternator can output 16 volts under load?

[Therapy]

Originally Posted by rickm505

Anyone have an idea of how a 10 amp alternator can output 16 volts under load?

Bad voltage regulator?

[96 P-23]

I would substitute a regular battery before condemming either battery or motor/charger.