Battery / Radio set up for SIB

[MustRib]

I have already posted something about this before, but am looking for a little more detail if any members can help.
I want to install a radio in my SIB. To power it I will use a battery (any tips on a small light 12v battery that can take a pounding?) and intend to charge the battery from the 2 pin connector out on the front of my Yam 20d outboard.
The question I have ...is what I will need to do that?
I am assuming that the power supplied from the 2 pin out on the motor will be a little erratic?? so some form of regulator is needed maybe? Anyone got any ideas about this..or indeed has set up a similar system themselves?
What equipment did you use?

My intention was to clamp the battery into a battery box, and that in turn be attached onto a bracket fixed to the underside of the bench seat. The radio would also be mounted here. Any advice suggestions on a battery cut off switch or fuse panel?

Loads of questions here, but would like some advice before going any further with it...
thanks all
Andy

[JABS]

Andy,

Whilst I am not familiar with this engine, the output is likely to be from what is often referred to as a 'lighting coil'.

The voltage will be fairly coarsly controlled, low at low RPM and high at WOT. It is designed for running lights which are pretty tolerant of input voltage. Charging a battery is a whole different ball game.

I suggest you ask Yamaha to tell you what the output is and, if suitable, find a suitable charging regulator.

It could be a whole lot easier to take the battery home to charge it!

Sorry to be negative!

Tony.

[J S]

Hi

I have the same sort of boat, Is there a reason why you are not considering a handheld.

James

[MustRib]

I have the same sort of boat, Is there a reason why you are not considering a handheld.

I like to get about in the boat, and take it a few miles offshore and up the coast a ways..... Its not unusual to be the only boat for several miles around. I have a handheld as well.... I just wanted the security of a radio with a greater range.

[Daniel]

The new Icom M71 h/held is 6w which is a high o/p for a hand held. I intend to buy one.

As JABS says the engine o/p is almost certianly designed for powering lights and although likely to be DC is almost certianly unregulated. You should be able to check this because if it is DC then the two yellow wires appearing from under the flywheel will "goto" a rectifier which i would expect to find mounted on the side of the engine somewhere, and almost certianly has a short black wire connecting it to ground by one of its mounting bolts. This unit will in turn be connected to the connector on the front of the engine you cite.

Prehaps post a piccy if you are unsure.

I say all of this based on experience of the same system on the Yam30.

Assuming the o/p is DC and not AC then you have two options to charge your battery. (1) make a regulator circuit and house it somewhere and (2) buy a unit to do the same job.

Depending upon you knowledge and skill someone on RIBnet can help you with either. I expect RS www.rswww.com sell something that will do the job but if you have access to a soldering iron and know how to use it i or someone on here would be able to tell you the 3 or 4 components needed to build this yourself (and cheaper)

Let us know what category you fall into.

[vince]

Hi MustRib, we had a sib with a similar setup, just enclosed the undersides of the bench seat in plastic, mounted the radio and switch panel, with a jetski battery underneath. All we did for charging was to mount a waterproof caravan cig charging plug going back to the battery. Charging was a doddle, just took off the crocodile clips from charger and fitted a male cig end. Worked everything for ages, hardly ever needed charging, and that was with navlights as well. Even had a fishy finder!

[MustRib]

great replies ...thanks a lot...

I definitely fall into the "best buy something off the shelf" category...
so if you could recommend a voltage regulator I would be interested.

the under seat set up on the Zodiac looks just the the sort of thing I had in mind....

anyone else done this sort of set up on a SIB?

[Daniel]

This will do the job for less than a tenner (it's designed for AC aswell so even more universal) http://cpc.farnell.com/jsp/Car,+Leis...sp?sku=HK00218 but you will need to assemble it. Being variable voltage o/p you should be able to set the o/p to say 13.5v which is a nice voltage to charge a small 12v battery.

[jyasaki]

I used a lawn and garden battery in an Achilles 14'. A couple of footman loops (little metal belt loops, essentially) riveted to the floorboards, the battery in a plastic box, and the whole thing strapped down. I had a handheld VHF, as I didn't stray too far afield in that boat (usually). The battery was replaced once, after about 3 years; took a beating over its lifespan. Replacement was something like $35 US.

If you go with a full-size VHF, remember that full power transmission will draw about 7 amps or so from the electrical circuit. If you plan on talking a lot while the motor is shut down, size the battery appropriately.

jky

[MustRib]

once again thanks to all on here...very helpful advice.