Battery charging - Yamaha 30

Searider · 31 March 2007, 22:07

Picked up the Searider this afternoon and am thinking about an automatic bilge pump and nav lights. Possibly an echosounder.

The engine is a completely manual 3 cylinder Yamaha 30 of about 1995 vintage.

Does anybody know if this engine can charge a battery? Or, can it only light nav lights?

There is a socket on the lower front left hand corner of the engine.

Had forgotten how much fun a small boat can be!

Nos4r2 · 01 April 2007, 08:06

Any labels or anything on the socket?

It'd be easier if I could see it.

Searider · 01 April 2007, 19:09

This is the fitting.

Nos4r2 · 01 April 2007, 19:20

It LOOKS like a charging system but some don't have rectifiers on the engine.

Start it up and hook a multimeter set to AC around 50v and see what reading you get.
Do the same with it set to DC20v
If you get a reading over about 3v on AC there's no rectifier.
You should get 12-16v open circuit voltage on DC if there's a rectifier.

Searider · 01 April 2007, 19:31

I'll give that a go tomorrow.

I assume if I get any AC it's not much cop for charging a battery - just good for nav lights.

Regards

Duncan

Nos4r2 · 01 April 2007, 19:37

Quote:

Originally Posted by Searider

I'll give that a go tomorrow.

I assume if I get any AC it's not much cop for charging a battery - just good for nav lights.

Regards

Duncan

If it's AC you'll need a rectifier and/or regulator and battery depending on voltage before you can use it-even for nav lights.

rickuk3 · 01 April 2007, 20:10

If you need a rectifier/regulator these people supply a great unit at a good price http://www.trailtechproducts.co.uk/store/erol.html

Richard

Jizm · 01 April 2007, 21:01

My 1995 25hp yam had the same socket. It was a DC outlet to power nav lights or charge a battery. I used it to trickle charge a motorcycle battery as the charge circuit was not big on power, about 130w if I remember correctly according to the manual. If connected directly to the nav lights then obviously the brightness is proportional to engine revs, the higher the revs the better the lights, dimming to almost nothing on tickover. Putting a battery in the circuit cures this. Don't bother with the proper plug, it's expensive. Standard 6.5mm crimps should fit the terminals.
hope this helps.
Jiz

Searider · 01 April 2007, 21:44

Cheers Jiz,

When you say motorcycle battery - do they come in 12 volts?

I'll see what my multimeter tells me.

When you say the plug was expensive - how much?

Duncan

Searider · 01 April 2007, 21:58

Richard - some good looking gear on that site.

Nos4r2 · 01 April 2007, 22:03

Knowing it's a 12v DC output makes it easier!

As you're not using an electric start then rather than using a motorbike battery personally I'd grab one of these.

You'll need one of the larger 12v ones so it's not overcharged-the UD03D would do. That way you'll never have to worry about it leaking or getting salt water inside (nasty-gives off chlorine!).

Searider · 01 April 2007, 22:16

I like the look of those.

But what I guess I need to do first is determine if the output is regulated.

I presume a regulated output will be a constant ish voltage irrespective of engine speed. This I guess would be OK to charge a battery.

Unregulated will vary - hence brighter and dimmer lights? Maybe not OK to charge a battery.

It's all a big change from the 60A alternator and two 90Ah batteries on the Scorpion!

Might also have a chat with my friendly local Yamaha dealer.

Nos4r2 · 01 April 2007, 22:24

A regulated voltage will be around 14.8-15v max at over about 2000rpm (rough figures). You may get brighter/dimmer lights on a small output charging system anyway-they put out hardly anything at tickover.

On such a small charging system you can put the battery in there and it'll act as a 'soak' anyway and should stop voltage soaring and frying stuff even if it is unregulated-just make sure the battery contracts are good and can't come off!
My old merc blueband was rectified but unregulated and was fine until the battery isolator died and the unregulated output went through the instruments and fried the VHF.

Jizm · 02 April 2007, 07:56

Quote:

Originally Posted by Nos4r2

Knowing it's a 12v DC output makes it easier!

As you're not using an electric start then rather than using a motorbike battery personally I'd grab one of these.

You'll need one of the larger 12v ones so it's not overcharged-the UD03D would do. That way you'll never have to worry about it leaking or getting salt water inside (nasty-gives off chlorine!).

Agreed,

those batteries would be better and as you say the12ah one ideal.

I think the plug was around £10-15 but at the time I was young and impatient and would rather spend my cash in the pub. I took the bike battery out of my kwak 750 when I went boating cos I was too tight to buy another battery for the boat...

jyasaki · 04 April 2007, 16:46

Searider: A garden and tractor battery will be fine. Used one with my Honda 40/4 on my 14' Achilles. Cheap, easy to find, and they seem to last quite well as long as you run the thing every now and then (mine was used to start the motor, though.) Got mine at a hardware store for $29 US (with a $10 core refund for the old one. So $19 total cost.)

The battery will help stabilize the voltage levels a bit; and I'd be a bit surprised if bright/dim lights at varying rpms was any issue at all.

You *may* be able to avoid having to get the connector if you pull the cowl and trace the wires back; if they're bolted on to the regulator output, you can bolt your battery cable on directly (I'm a believer in the fewer the connections the better.)

Luck;

jky

Poly · 04 April 2007, 22:49

Searider - I have a wee 20HP yam - but it has electric start (and therefore the alternator for charging electics). When I looked at the cost of battery, cables, battery box, isolator switch, 12V accessory socket, fuses etc I started having thoughts like yours. Then I got one of these "jump start" boxes you get for cars (21 Ah ? I think) and wired it in - this cost much less (has integrated switches / isolator / fuse etc). It lives inside the console and if it packs up because it gets wet then it doesn't matter as the engine has pull start too... electric is just to save me the effort. So far so good (over a year old, and even got a little wet on the odd occasion).

Searider · 08 April 2007, 17:53

Got my multimeter on the terminals and it looks like an AC output. Was getting about 8-9 volts at a high idle. So, loks like i'll need some sort of rectifier / regulator - or just keep things simple and use a bailer for getting the water out of the boat!

jwalker · 08 April 2007, 20:17

Post 19

jyasaki · 09 April 2007, 05:26

Quote:

Originally Posted by Searider

Got my multimeter on the terminals and it looks like an AC output. Was getting about 8-9 volts at a high idle. So, loks like i'll need some sort of rectifier / regulator - or just keep things simple and use a bailer for getting the water out of the boat!

Was that 8 to 9 DC? Was there an AC component present? Or if it was AC was there a DC component present? (A DMM is really lacking for this type of checking. Most folks, me included, don't have an O'scope lying around, though.)

With no load the output could be doing all kinds of weird things. A couple of amps worth of load should smooth it out enough to see exactly what it's doing.

jky

Searider · 10 April 2007, 00:03

Looked to be pretty much AC.