2002 90TLRA charging/running volts?

[SeaDawg3]

Just finished an install of a pair of Yamaha multifunction gauges.
I am seeing 15.2 - 15.6 volts when cruising.
I was seeing the high end of 14 v on the past (new) analog needle gauge. I was expecting to have better accuracy with the Yamaha set up and I am.
Apparently the boat had been running this way as there was no volt gauge from the PO.
Everything appears fine. Battery is 5 months old and in good health.
Is this anything to worry about? Do I need a new voltage reg/rectifier?

[Parker Yacht]

Are you running anything while the engine is running?
Stereo, depth finder, ice maker, vibrator?

[SeaDawg3]

Are you running anything while the engine is running?
Stereo, depth finder, ice maker, vibrator?

Lol, yes a Hummingbird 100SX, a Lowrance Elite 4M GPS chartplotter, and a Fusion RA-50 Stereo.
Same as before with the Faria gauges.

[SeaDawg3]

I turn on the stereo while underway to reduce the volts. Some had mentioned to turn on the Nav lights or an accessory to drop the volts if it gets to high. Assuming 14.5 is the norm.

[Parker Yacht]

Yea, well, unless that RA-50 has an amp attached to it, there is no draw.
Really is no downside, unless you have AGM or Gel batteries.

[SeaDawg3]

Yea, well, unless that RA-50 has an amp attached to it, there is no draw.
Really is no downside, unless you have AGM or Gel batteries.

no amp... weird just the first time I`m seeing 15+ volts with the better gauge.
Flooded acid battery, Everstart wally world 24DC. only 5 months old. static volts of 12.77

I have a new rec/reg coming from SIM. if anything else I`ll have a spare to toss in the tool box.

[SeaDawg3]

I was informed there was a service bulletin during the same year/period of the 2002 90, just for this charging issue. I`m curious to hear or know what it reads. If anyone has access to this, please post... thanks...

[SeaDawg3]

ok, as ya`ll know I have 2 batteries. one 5 mons old and the other 2.5 yrs old.

they both maintain 13+v on the battery tender and go green in short order.

I just finished replacing the reg/rectifier and here are the results.

Old battery fully charged with 12.8 after settling.
fire up the boat and see 12.8. 13.0, 13.2 up to 14.4-6volts from idle to 1500 rpm.

the new battery is on the tender and sitting at 13.15 v.
swap out the battery and immediately I see 15.4 at idle and can see 15.6-8 when rev`d to 1500 rpm...

not much of a difference but an immediate difference.

with either battery I can pull it down some by operating the trim, set a few minutes and refire, same results, brings the charging current up quick enough...

what does this tell me about the 2 different batteries?

there is a small variation of readings between the fluke meter and the actual Yamaha multi gauge. .5v to be exact.

ex: at the battery 14.7 at the dash, 15.2 this is on the new battery.

keep in mind that I never lost any water in the cells.


1st pic, older battery
2nd pic, newer battery