Charging Voltage

[Hightower]

Just an observation but in the last couple of months I've noticed the Voltage go up to 16/17 volts on the gauge whilst the outboard's running. Is this a normal voltage or a tad on the high side. Everything seems to be in good working order etc. Just thought it should be around the 15/15.5v range? What voltage does everyone elses outboards run at?

[Nos4r2]

Mine runs at 14.8 max, starting around 12.8 at tickover.

[Hightower]

Mines a pretty constant voltage and is about the same at tickover as it is at WOT.

[Top banana]

Originally Posted by Hightower

Just an observation but in the last couple of months I've noticed the Voltage go up to 16/17 volts on the gauge whilst the outboard's running. Is this a normal voltage or a tad on the high side. Everything seems to be in good working order etc. Just thought it should be around the 15/15.5v range? What voltage does everyone elses outboards run at?

Andy what does the voltage on your plotter read, 17v sounds high to me,
mine used to show 14.8, and 12+ withengine off.

[PeterM]

12.5 off & 14.2 running on the ,and 13 & 15.2 on the Yamaha.

[jwalker]

16-17v is battery frying if the electrics are in proper order. Put a multimeter on there Andy to be sure of the correct voltage. Start checking at the battery terminals.

[Hightower]

Each Battery is showing 12.6v when everythings turned off.

I'll run up the outboard tomorrow and do some checks. The Chartplotter and Depthfinder have voltage displayed so this will be my first check and see if everything matches in terms of voltage readings. If I'm showing 16 volts on everything then I'll run a meter across the positive and earth on the engine and see what I get.

It's certainly been this voltage for about 5 of my last trips and have probably covered about 200miles in total since I first noticed the reading. I just assumed that the plotters, engine management etc would have put up an alarm if there was a serious problem.

[Bam Bam]

Originally Posted by Hightower

Each Battery is showing 12.6v when everythings turned off.

I'll run up the outboard tomorrow and do some checks. The Chartplotter and Depthfinder have voltage displayed so this will be my first check and see if everything matches in terms of voltage readings. If I'm showing 16 volts on everything then I'll run a meter across the positive and earth on the engine and see what I get.

It's certainly been this voltage for about 5 of my last trips and have probably covered about 200miles in total since I first noticed the reading. I just assumed that the plotters, engine management etc would have put up an alarm if there was a serious problem.

You need to be careful if the charge voltage reading is much above 15V as this could lead to gassing of the battery which should, on a modern battery be vented by a small valve. 16V to 17V is too high in my book. But that just my opinion and I may be proved wrong... but I doubt it. However, when a battery is over charged the gas released is a mixture of Hydrogen and Oxygen which is very explosive and if over charging is happening you should be able to smell a acid smell in the proximity of the battery if it has a valve. If you can smell acid near the battery while the engine is running at revs then turn everything off and have a qualified (auto) electrician diagnose the problem. If the battery does not have a valve then you could release one of the filler bungs, start the engine, and then see if there is a strong smell of acid I don't want to seem like a scare monger but over charged batteries can and do explode. Get it looked at mate, we don't want anything to go bad for you. On a lighter note... Change the elastic band... She might go faster!

[Chris]

If you are getting 16-17 volts it will be due to a gradually failing regulator. You will eventually fry the electronics at that voltage and the battery will fail as well.

14.8 Volts is the norm when the engine is running (regardless of RPM) then 12-13 volts when the engine is off.

[Hightower]

Batteries are SFL type and as far as I can tell there is no facility to refill, but as I understand it there is a vent. But I've never had any funny acidy smells in the console.

Perhaps the gauge is out of calibration. I'm going to give it a once over tomorrow and will let you all know how it goes.