Battery charging.

blueboy758 · 15 July 2008, 08:00

I have an evinrude 50 vro, and all the usual electronics.(echo sounder, gps and vhf)
when the engine is running watts the optimum volts it should be generating to keep the battery topped up? as well as running with the electronics turned on, if possible.

thanks

phil

captnjack · 15 July 2008, 17:12

About 14.5V regardless of what electronics are on. Outboards have constant voltage regulators. They deliver less current when idling and more when revved up and the demand is there. Less than 14V is not going to charge adequately and more than 15.5V is going to boil electrolyte.

al40 · 15 July 2008, 21:04

Yip - 14.4v is the magic number!

Unfortuantely, I think a lot of smaller outboards don't quite make it to that voltage (last 2 of mine haven't). A car with fully charged battery will sit happily at 14.4 with engine running.

For what it's worth, I got one of these to give my battery a treat once in a while (currently using it to recover a car battery that went completely and utterly flat with lights left on for a week).

http://www.ringautomotive.co.uk/cats...cat1=7&cat2=31

Into The Blue · 15 July 2008, 21:58

I've got a 70VRO thay'll happily sit at 17volts at full throttle, makes the radio tell me turn it off. "Over voltage" alarm. And it'll fry the battery eventually. The older VROs do not have a voltage regulator so can vary voltage with revs.
Anyone got any ideas on how to cure it I'd be very grateful

Lugnut · 16 July 2008, 03:32

Quote:

Originally Posted by Into The Blue

I've got a 70VRO thay'll happily sit at 17volts at full throttle, makes the radio tell me turn it off. "Over voltage" alarm. And it'll fry the battery eventually. The older VROs do not have a voltage regulator so can vary voltage with revs.
Anyone got any ideas on how to cure it I'd be very grateful

My suggestion for somebody on a budget would be to use an automotive voltage regulator. A mid 80's caprice would have a regulator rated for more than 100 amps. PLENTY of capacity and the standalone regulators are usually sealed. They run about 20 dollars on this side of the pond.

I had a 1983 Toyota truck that had seperate sealed voltage regulator too.

Nos4r2 · 16 July 2008, 12:24

Quote:

Originally Posted by Lugnut

My suggestion for somebody on a budget would be to use an automotive voltage regulator. A mid 80's caprice would have a regulator rated for more than 100 amps. PLENTY of capacity and the standalone regulators are usually sealed. They run about 20 dollars on this side of the pond.

I had a 1983 Toyota truck that had seperate sealed voltage regulator too.

Far easier on old engines to use a combined voltage regulator/rectifier from a Honda 250/400 Superdream. They are a nice sealed unit too.

To wire it in,remove the original outboard rectifier.On the Honda item, 2 of the 3 yellow wires go to the outboard alternator. Tape up the 3rd. Green goes to earth/negative from the old rectifier, RED AND BLACK goes to the live side of the starter solenoid. Tape up any others. DO NOT attach the black to earth-on this unit GREEN is earth and the black wire is a secondary live feed.

Into The Blue · 17 July 2008, 22:48

Thanks - that will be really useful, just got to go find one now
Bike Breakers R Us here I come

Nos4r2 · 17 July 2008, 23:25

Quote:

Originally Posted by Into The Blue

Thanks - that will be really useful, just got to go find one now
Bike Breakers R Us here I come

Either that or (just remembered these guys) http://www.electrexworld.co.uk
They'll do you a rectifier/regulator unit for your 2 phase alternator and it'll be better than the superdream unit. Won't be too expensive either.

The RR60 unit should be perfect and only £45.It's for a Kawasaki KZ750 (2 cylinder) Both yellows to your alternator, red to live side of starter solenoid, black to earth.